Sciencemadness Discussion Board - Interests in Radioactivity & Nuclear History

Interests in Radioactivity & Nuclear History

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bfesser - 28-8-2013 at 08:55

I, myself, have been thinking about purchasing and putting together one of these <a href="http://en.wikipedia.org/wiki/Geiger%E2%80%93M%C3%BCller_tube" target="_blank">Geiger–Müller tube</a> <img src="../scipics/_wiki.png" /> based radiation counter <a href="http://mightyohm.com/blog/products/geiger-counter/" target="_blank">kits</a>, for use as a practical tool in my mineral collecting. I've also thought about connecting it to a <a href="http://www.raspberrypi.org/faqs" target="_blank">Raspberry Pi</a> or an <a href="http://arduino.cc/en/" target="_blank">Arduino</a>, along <a href="http://www.adafruit.com/blog/2013/01/24/adafruit-ultimate-gps-on-the-raspberry-pi-raspberry_pi-raspberrypi/" target="_blank">with a GPS receiver</a> so I can map local background radiation on my rock-collecting hikes.

So, I ended up purchasing a mightyohm.com Geiger Counter kit with my latest tax return, and I have to say that I love this thing! The kit is very well engineered, and the components are top quality—the 555 is a Texas Instruments, the trimpot a Bourns®, EPCOS electrolytic, TDK piezo, etc.. The board layout is very nice, and the actual construction of the board is top-notch. Holes are all through-plated, the solder mask and printing are precise, and the edges are all smoothly routed—not those nasty snap-off edges! Anyway, the whole thing went together like a dream, and it's addictive to use. I'll write up a proper review later, and I'll try to get some photos of the assembly process (my father liked mine so much that he ordered one for himself). I'll also describe my modifications and ideas for future board revisions (it's Open Hardware). So far, I've interfaced it to an Arduino Uno and an iPhone 4S running Geiger Bot.
<img src="http://farm7.staticflickr.com/6039/6275026497_3cf9f175b2.jpg" width="500" height="375" alt="mightyohm.com Geiger Counter v1.0" />
Oh, and I plan to post on my adventures in radiation detection and collecting radioactive mineral specimens (plus a couple other objects), if anyone's interested.

[Edited on 3.9.13 by bfesser]

plante1999 - 28-8-2013 at 08:57

I am indeed interested!

I had bought that kit, but it never passed trough the customs, what an huge lost of money!

bfesser - 28-8-2013 at 09:00

Odd; I see no reason why it shouldn't have passed through customs. All of the components are already available in Canada, as are the source code and schematics. Was the kit returned to the seller or just confiscated?

plante1999 - 28-8-2013 at 09:04

confiscated. Probably due to "nuclear material" content.

bfesser - 28-8-2013 at 09:10

What nuclear material? The kit itself is no more radioactive than any other assortment of standard metallic objects. Did they send you any notification or explanation?

plante1999 - 28-8-2013 at 09:13

Nope.

I still want one of those, but I already have spend the cash one time, so yea.

bfesser - 28-8-2013 at 09:18

Well, I plan to renew my passport soon and will be taking a short excursion into Canada (Ontario). I'll let you know when; maybe I can order a kit, drive it across the border, and mail it to you from there? Do you have customs between provinces?

[Edited on 28.8.13 by bfesser]

Fantasma4500 - 28-8-2013 at 09:34

gotta love how well informed people worldwide really are, that is really horrendous, plante..

if you would like to go gather some radioactive minerals, im sure greenland is the place to go, of what i know they have a decent stock of thorium laying around, which has been discussed to replace uranium, buuut darker plans are probably the only thing that took it off the list

IrC - 28-8-2013 at 11:04

bfesser if you need something to test let me know. I have a few rocks laying around. Actually used my bargraph counter to find the box in storage once. Was tired of opening one after another. Coffinite is probably the hottest rocks you will find in your area but rare. Best ore for testing there is. However in your area look for old sedimentary deposits in sandstone since Carnotite (yellow crystals) is mostly what your state has.

Don't say it. Why didn't I mark the box. My dog ate my magic marker?

mr.crow - 28-8-2013 at 12:17

Quote: Originally posted by bfesser

Well, I plan to renew my passport soon and will be taking a short excursion into Canada (Ontario). I'll let you know when; maybe I can order a kit, drive it across the border, and mail it to you from there? Do you have customs between provinces?

[Edited on 28.8.13 by bfesser]

Not between provinces. Its our great and empty land

That's bullshit it was confiscated! Tons of people bought Geiger counters after the Fukushima disaster. Maybe the box was labelled poorly and some highschool drop out power tripped and took it.

bfesser - 28-8-2013 at 13:31

IrC, thank you for your offer and information—I have plenty of test sources, though. I have a small <a href="http://webmineral.com/data/Torbernite.shtm" target="_blank">torbernite</a> <img src="../scipics/_ext.png" /> specimen, a pair of Th <a href="https://en.wikipedia.org/wiki/Gas_mantle" target="_blank">lantern mantles</a> <img src="../scipics/_wiki.png" />, and a disturbingly <a href="https://en.wikipedia.org/wiki/Hot_cell" target="_blank">hot</a> <img src="../scipics/_wiki.png" /> <a href="http://www.redwingpottery.com/" target="_blank">Red Wing</a> <img src="../scipics/_ext.png" /> ceramic plate with orange glaze from the 1930's (before uranium enrichment). I'll be sure to keep an eye out (or should I say an ear?) for <a href="http://www.mindat.org/photo-13783.html" target="_blank">coffinite</a> <img src="../scipics/_ext.png" /> and <a href="http://www.mindat.org/min-907.html" target="_blank">carnotite</a> <img src="../scipics/_ext.png" />, though. I've seen on geologic maps that Minnesota has(/had?) some uranium mines, but I haven't put any further effort into researching them yet.

Wizzard - 28-8-2013 at 15:11

I have some family in Canada - I might be able to help if something is stuck up there.

IrC - 28-8-2013 at 16:05

@bfesser "disturbingly hot"

How hot in mr/hr?

Ozone - 28-8-2013 at 17:35

Thanks! I'm soooo buying one of these.

BTW, I've got some old Bauer and Fiesta ware that will also ping a GM. I'm not sure how viscerally disturbing 2000-5000 cpm is, though. Doesn't bug me, but they are excellent test sources.

Cheers,

O3

[Edited on 29-8-2013 by Ozone]

Hot plate?

bfesser - 28-8-2013 at 18:20

IrC, as you know, the kit's neither calibrated nor a lab-grade instrument and I have yet to take a proper reading (just listened to the chirps/watched the flashes) but it seems to be more so than the torbernite specimen. Of course, it has a larger surface area, and the U is distributed near/on the surface, as a component of the glaze; whereas the torbernite (likely) has a higher density and much of the decay within the specimen won't be detected. (Or so I understand it at this point.) I'll try to get some semi-quantitative data tomorrow. I was just given the second kit to assemble, so I'll try to do that tomorrow, as well.

I'm hoping to at least calibrate the two against each other, if nothing else, so that a reading on one will be repeatable by the other. Since they ship with the <a href="http://gstube.com/data/2398/" target="_blank">SBM-20</a> <img src="../scipics/_ext.png" /> <a href="https://en.wikipedia.org/wiki/Geiger%E2%80%93M%C3%BCller_tube" target="_blank">Geiger–Müller</a> <img src="../scipics/_wiki.png" /> (G–M) tube, which is well characterized and widely deployed, an approximate dose-rate is calculable from the counts per minute (CPM). In fact, the <a href="http://www.atmel.com/devices/attiny2313.aspx" target="_blank">ATtiny2313</a> <img src="../scipics/_wiki.png" /> that ships with the kit is <a href="http://mightyohm.com/blog/products/geiger-counter/source-code/" target="_blank">pre-programmed</a> <img src="../scipics/_ext.png" /> to do so, and outputs the data to the <a href="http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232R_CABLES.pdf" target="_blank">FTDI-compatible serial header</a> <img src="../scipics/_pdf.png" /> once every second.

Finally, I forgot to list my beloved <a href="https://en.wikipedia.org/wiki/Trinitite" target="_blank">trinitite</a> <img src="../scipics/_wiki.png" /> specimen in my last post.

A few noteworthy webpages I've come across:
<a href="http://hps.org/publicinformation/ate/faqs/radiation.html" target="_blank">Radiation Basics</a> <img src="../scipics/_ext.png" /> (Health Physics Society)
<a href="http://hps.org/publicinformation/ate/cat47.html" target="_blank">Radiation Basics</a> <img src="../scipics/_ext.png" /> (same site & title, different page... bad web design practice)
<a href="http://modernsurvivalblog.com/nuclear/radiation-geiger-counter-the-radiation-network/" target="_blank">Geiger Counter Numbers, How Bad is Bad?</a> <img src="../scipics/_ext.png" /> (Modern Survival Blog) — Neither authoritative nor a philosophy that I subscribe to, but a concise and informative read.

P.S. I suppose "disturbing" wasn't the word I sought; perhaps 'surprisingly hot' would describe it better. I went to an antique shop with my counter and the plate was the first thing I tested; I hadn't expected anything above backround. It's a little disturbing, though, to think that someone scraped their knife and fork across the glaze and ingested the tiny dislodged radioactive particles (or worse; inhaled them). I'm not unduly scared of it, but prefer to minimize my exposure, and won't allow the cat sleep on it for warmth.

[edit] Oh! IrC, I recall seeing that you have knowledge in Electrical Engineering and instrumentation. I may have a few questions for you in the near future, if that's all right. I don't consider myself knowledgeable in anything, really; rather I tinker around in many overlapping areas of interest, and pick up a few tidbits of trivia here and there. I always seem to end up with more questions than anything else...

</end of rambling post—I promise!>

[Edited on 29.8.13 by bfesser]

BobD1001 - 28-8-2013 at 20:49

What an awesome Gieger kit! I just purchased a kit from electronicgoldmine a couple weeks ago, their miniature Geiger board one was on sale for $15, and I bought an SBM-20 on eBay. Sadly something seems defunct in the components of the kit, not sure exactly which component however. Had I seen this one from mightyohm, I would have purchased it in a heartbeat over the electronic goldmine kit.

Varmint - 29-8-2013 at 03:28

bfesser:

Since the counter is a raw event counter, there really is no calibration other than to insure the HV is high enough to create the conditions for an arc channel through the halogen gas, but no so high as to false trigger or create a channel that is so energetic the quench has a hard time making recovery for the next event.

Calibration would be required if you were displaying the counts (say on a meter movement).

At the low end, you have few counts in a second, so you need to integrate them over time, then amplify the result to give a useful meter sweep.

At the high end, you might have thousands of CPM you still need to average over time, but in this case the result of the integration would present too high of a meter deflection, so the higher setting amounts to more of an attenuation.

The ideal case for this would be an Arduino where software counts the pulses, and auto-ranges the meter display all on the fly.

I did something similar with a Motorola Mc68HC11 almost 2 decades ago. I counted the pulses, the pulses per second ended up be an index to a table in ROM that was used to drive a meter movement via a D/A converter, and at the same time, the code set the range LED when in automatic mode.

In either automatic or manual range selection modes, the D/A output was restricted to avoid slamming the meter needle but still give good response to rapid swings in the actual CPM. This gave you the intuitive analog meter pointer, with digital conditioning to avoid damage and enhance response. A quick glance at the LEDs told you which scale you were in.

The final implementation had green, yellow, orange, red, and a high brightness flashing LED to represent the scales.

Basically if the LED was green all was well, if flashing red, get the hell out of Dodge!

Very interesting project, unfortunately the victim of a common thief who lifted it off my table at Hamfest.

PS: Don't forget to take some readings on Beer, bananas, and nuts of all varieties. 40K is everywhere!

DAS

[Edited on 29-8-2013 by Varmint]

[Edited on 29-8-2013 by Varmint]

[Edited on 29-8-2013 by Varmint]

IrC - 29-8-2013 at 13:12

Quote: Originally posted by Varmint

Don't forget to take some readings on Beer, bananas, and nuts of all varieties. 40K is everywhere!

But I like bananas

http://www.youtube.com/watch?v=lWcxZe_-Wrs

Is that why my mind is glowing?

dontasker - 31-8-2013 at 02:46

Tempting. Very tempting. It's also a great price.

I know the kit from SparkFun got some attention when they first started selling them. There were some interesting projects with people using it for random event/number generation.

The random generator may be easier to do with a webcam and a pinch of some alpha emitter.

Speaking of radiation and CCDs, there's an app for that.

Quote: Originally posted by BobD1001

What an awesome Gieger kit! I just purchased a kit from electronicgoldmine a couple weeks ago, their miniature Geiger board one was on sale for $15, and I bought an SBM-20 on eBay. Sadly something seems defunct in the components of the kit, not sure exactly which component however. Had I seen this one from mightyohm, I would have purchased it in a heartbeat over the electronic goldmine kit.

They have a few nice tubes on their site.

My father and I both share a love for odd gadgets. He's an old electronics engineer so he was buying tubes and building the rest out of stuff he already had. I think he ordered some of the tubes from someone out of Russia via ebay. I think it ended up being much cheaper than any domestic source.

bfesser - 2-9-2013 at 14:16

Thanks for sharing the link, dontasker. I've been a subscriber to that channel for quite a while, but hadn't seen that video yet. I tried the app out on my iPhone 4S. It did indeed detect the above-background radiation from my U-glazed plate, although the rate wasn't comparable to my kit Geiger counter. Perhaps I didn't calibrate it properly, didn't allow it to sit on the plate for long enough, or just have a <a href="https://en.wikipedia.org/wiki/Charge-coupled_device" target="_blank">CCD</a> <img src="../scipics/_wiki.png" /> from a poor batch for this purpose. I wonder if anyone's tried converting the camera module or a cheap USB webcam on the Raspberry Pi to this purpose.

On a related note, I'm working on setting up the serial interface between a RasPi Model A and the Geiger counter. I'm also going to add an 4 digit 7-segment LED display on an <a href="https://en.wikipedia.org/wiki/I%C2%B2C" target="_blank">I2C</a> <img src="../scipics/_wiki.png" /> backpack to display current background levels and local temperature (+ other weather data) along with a separate 10mm diffused LED as a warning indicator. I'd like to stream the data from the counter up to <a href="https://xively.com/" target="_blank">xively™</a> <img src="../scipics/_ext.png" /> (Cosm/Pachube)—or whatever they'll be known by next week— as well.

Varmint, I'm sorry to hear of the theft; your project sounds interetsting. As for readings from food, it wouldn't be detectable by this kit.

Finally, I assembled the second kit, and it worked perfectly. I was too lazy to take photos, but I might still write up a complete review later.

dontasker - 2-9-2013 at 17:54

I love the idea of using a Pi for a web accessible radiation monitor. It's almost disappointing that there aren't many nuke tests anymore. It would be interesting to set up a world-wide network of monitors and see how the debris propagates.

Please work on a write up of your project. I have 3 RPi units that I'm looking for new projects to use them in. They're amazing toys and I always get some useful ideas from seeing how other people choose to go about their creations.

Plutonium239 - 2-9-2013 at 19:30

Thanks, I will look into it. I currently use a CD V700, and it's not very portable, as you can imagine. I've been looking for a very portable one (I considered the Gamma Scout, as my friend seems happy with it). I also have an interesting "nuclear" collection, including:

Reagent grade uranium dioxide
Multiple americium-241 pellets
Two lead pigs (I almost got a PET tungsten pig on eBay, but someone outbid me)

Gamma sources, including:
Cesium-137, cobalt-60, cobalt-57, cadmium-109, sodium-22, manganese-54, barium-133

I almost got a Victoreen neutron detector, but once again, someone outbid me. I wanted it because I assembled a very low-power neutron gun, but I'm not going to work on it anymore until I can find a cheap neutron detector that doesn't require the outrageously expensive helium-3 isotope.

It's nice to meet someone with similar interests in radioactivity, and I look forward to hearing more about your collection.

IrC - 2-9-2013 at 21:38

Quote: Originally posted by Plutonium239

until I can find a cheap neutron detector that doesn't require the outrageously expensive helium-3 isotope

Unlikely you will find one cheap. You can build a Neutron counter using your CDV-700. Schematics are easy to find for it. Alter it so you can adjust the voltage from 400 to 900 volts which you will adjust for the tube being used. Now build a neutron detector assembly. Adjust your voltage to get the tube working properly but do not put an excessive voltage on the tube. First one I built was crappy. I melted 3 pounds of Borated Paraffin keeping it in motion while I added an ounce of fine Ag dust, cooling while trying hard to keep the dust from settling. Damn near impossible I might add. Drill the block to accept your Geiger tube. The wax slows the Neutrons, the Ag produces a Gamma from a slowed down Neutron. Enclose it with lead foil or background Gamma will confuse the issue. No way to tell if you are detecting a Neutron or background radiation. Of course if using the OEM tube in the counter voltage adjustment is not required. I altered mine to try many tube types. For example around 590 volts is correct for the B(10) tube mentioned next.

Better is to find a B(10) tube (I bought a Russian surplus tube on ebay for $40), insert it into a moderator (Borated plastic works better than the wax). Again provide a Pb foil Gamma shield.

Right now I am playing with Photomultiplier tubes and a ZnS(Ag) screen (still need moderator). I have wanted to try the Li(6)-ZnS(Ag) material but have not found this cheap anywhere thus far.

I had less than $100 total into my first detector although it does not work very well. Of course how well it really works is not easy to tell since my Be foil + Alpha emitter = Neutron guns don't exactly produce a steady stream of Neutrons. IIRC it's about one Neutron for every 30 million Alphas. The worst problem is keeping all the background out of the detector no matter which method you try. Was it a Neutron or a Gamma? Not easy to know. Actually pretty impossible to tell. Best method is to be sure using shielding which does not allow any Gamma within a reasonable energy. Easy to test with all the sources you list. If your detector does not see your sources but does provide a count from your Neutron gun you can be fairly sure of what you are detecting.

At least this is how I try to determine what I am actually measuring.

Links for info on building circuits:

http://charliethompson.50megs.com/Radiation_Page2.html

http://mcs.uwsuper.edu/sb/Electronics/Geiger/

bfesser - 3-9-2013 at 05:44

Here are some eBay listings I came across last week that you might be interested in:
<a href="http://www.ebay.com/itm/160594077799" target="_blank">Russian Geiger NEUTRON Counter SNM-9 SNM9 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/160741457807" target="_blank">Russian Geiger NEUTRON Counter SNM-11 SNM11 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/160741457788" target="_blank">Russian Geiger NEUTRON Counter SNM-12 SNM12 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/160728973374" target="_blank">Russian Geiger NEUTRON Counter SNM-13 SNM13 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/400278432826" target="_blank">Russian Geiger NEUTRON Counter SNM-14 SNM14 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/161010077619" target="_blank">Russian Geiger NEUTRON Counter SNM-17 SNM17 NEW LOT 1</a> <img src="../scipics/_ext.png" />
<a href="http://www.ebay.com/itm/161089397813" target="_blank">Russian Geiger NEUTRON Counter SNM-42 SNM42 NEW LOT 1</a> <img src="../scipics/_ext.png" />

I ordered a CI-3BG tube from the same seller, and am waiting for it to come in the mail:
<a href="http://www.ebay.com/itm/160639267176" target="_blank">Russian Geiger TUBE Counter CI-3BG / SI-3BG NEW LOT 1</a> <img src="../scipics/_ext.png" />

And of course, no discussion of amateur nuclear anything is complete without mentioning <a href="http://unitednuclear.com/" target="_blank">United Nuclear</a> <img src="../scipics/_ext.png" /> (they sell <a href="http://unitednuclear.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=borated" target="_blank">borated paraffin</a> <img src="../scipics/_ext.png" /> and <a href="http://unitednuclear.com/index.php?main_page=product_info&cPath=2_9&products_id=490" target="_blank">Pb sheet</a> <img src="../scipics/_ext.png" />

.

I'm waiting on a shipment of four lead pigs from eBay which is due to arrive later today. And later this week, I should receive the parts I need to finish the RasPi set up. I will do a write up now that I know there's interest.

IrC, those links are great! Thanks for sharing.

[Edited on 3.9.13 by bfesser]

Marvin - 3-9-2013 at 06:29

Be aware that the Russian neutron counter tubes are corona tubes, a different animal entirely. There is some information on the Fusor Net forums and more specifics at Coulter's Smithing. Without a neutron source and a strong gamma source to set levels it may be impossible to measure neutrons and have any real confidence they are neutrons.

The SI-3BG may be less sensitive than you are hoping for. I rather like the SBM-20's.

bfesser - 3-9-2013 at 07:48

I'm currently using an <a href="http://gstube.com/data/2398/" target="_blank">SBM-20</a> <img src="../scipics/_ext.png" /> in my kit. I'm aware that the <a href="http://gstube.com/data/2486/" target="_blank">SI-3BG</a> <img src="../scipics/_ext.png" /> may be less sensitive, but wanted a spare tube to tinker with, and couldn't resist the glass envelope and smaller form factor. Also, the kit's designed to hold either an SBM-20, an SI-3BG, or an <a href="http://gstube.com/data/2480/" target="_blank">SI-1G</a> <img src="../scipics/_ext.png" /> by soldering the clips to different pads—I plan to order extra <a href="https://en.wikipedia.org/wiki/Printed_circuit_board" target="_blank">PCBs</a> <img src="../scipics/_wiki.png" />. I'm waiting on a <a href="http://www.mouser.com/Search/ProductDetail.aspx?R=ROX0501G00FNLBvirtualkey61300000virtualkey71-ROX1/2-F-1G" target="_blank">1 GΩ resistor</a> <img src="../scipics/_ext.png" /> I ordered from Mouser, so that I can <a href="http://mightyohm.com/forum/viewtopic.php?f=15&t=487" target="_blank">adjust the high-voltage</a> <img src="../scipics/_ext.png" /> properly. Until last week, I didn't even know that they produced resistors over 10 MΩ—I had never seen one before. I'm sorely tempted to buy a <a href="http://www.ebay.com/itm/110990414351" target="_blanK">10 GΩ resistor</a> <img src="../scipics/_ext.png" /> just to display on a shelf with a tag that reads "<img src="../scipics/_warn.png" /> Achtung! 10,000,000,000 Ohms <img src="../scipics/_warn.png" />."

SBM-20 (top) vs. SI-3BG (bottom):

I hope to accumulate an entire collection of detection instruments, including G–M tubes, and related items. Maybe later I'll get out my <a href="http://www.civildefensemuseum.com/cdmuseum2/radkits/cdv7772kit.html" target="_blank">CD V-777-2</a> <img src="../scipics/_ext.png" /> for some photos.

IrC - 3-9-2013 at 10:28

Marvin, This may be useful to those experimenting:

http://www.hardhack.org.au/neutron_monitor

bfesser, do not touch that resistor -ever- or you will ruin it. Use Hemostats. On the leads near the body, not the body!

Also, those glass tubes suck. One I tried worked for a while at around 470 volts then died. Also they need very high radiation flux it appears. Either the ones I tried needed a special circuit (I have yet to see in print) or they are not very sensitive and/or reliable. Higher voltages seem to ruin them rapidly. Out of a handful I tried only one worked, for a short time. Their operating region seems to vary, then they fail.

Of the Russian surplus the tiny SBM-21 appears to be the most reliable and very sensitive. I built one counter using the SBM-21 with a flash unit I hacked from a throw away camera. Powered by two AAA batteries in a tiny project box it is one of my favorite Geiger counters. Freaky how sensitive, reliable, and overall very cool from a hardware hacker perspective this tube is to play with.

Here is an image I found on fleabay of the tube:

[Edited on 9-3-2013 by IrC]

bfesser - 3-9-2013 at 11:09

Interesting, I had expected lower sensitivity, but hadn't considered the shielding effects of the glass. Also, I hadn't thought about the effects of fingerprints on the resistor (if that is why you're warning me). Would it be alright to handle it with clean nitrile gloves—I tend to wear them while soldering anyway? If not, I do have hemostats... I'm a geek, what can I say?

I doubt I'll get any accuracy regardless, with my shite <a href="http://www.radioshack.com/product/index.jsp?productId=2103176" target="_blank">RadioShack multimeter</a> <img src="../scipics/_ext.png" />. I've been using the junky thing for years, and should really invest in a better one (Fluke?).

[edit] IrC, I'm a little confused by the hardhack.org page you linked to. Is there more to it, or does their write up just end with the 'specifications'? They seem provide a circuit diagram, and then no evaluation or conclusion. I can't seem to find anything detailing the actual projects. I must be missing something...

[Edited on 3.9.13 by bfesser]

IrC - 3-9-2013 at 12:13

Quote: Originally posted by bfesser

Also, I hadn't thought about the effects of fingerprints on the resistor (if that is why you're warning me). Would it be alright to handle it with clean nitrile gloves—I tend to wear them while soldering anyway? If not, I do have hemostats

Yes the chemicals coming off your skin gets into the surface of the resistor and not only alters the value, the value keeps changing with humidity. Forever ruined. My hundred billion ohm resistors have been altered from much handling using even good gloves, thus my learned behavior of using Hemostats on the leads only, close to the body. Held further down the lead torque is multiplied against the seal on glass body resistors. Not so bad on some plastic body resistors. Unsure what the plastic is chemically, it matters in the hundred billion ohm range but no doubt that was taken into account by the MFG.

"Is there more to it, or does their write up just end with the 'specifications'? They seem provide a circuit diagram, and then no evaluation or conclusion"

Have not had time to really study the site. I see it from the perspective of what circuit I will design around the circuitry shown, although this probably is of little use for those needing a completed project. To me I see what is needed to operate the tube and go from there.

I keep forgetting to mention but if hard to find high value resistors are needed, buy some old CDV-715'S. I just love hacker supplies.

[Edited on 9-3-2013 by IrC]

bfesser - 3-9-2013 at 12:46

Interesting. Thank you so much for all of your advice on this subject, IrC. I'm just a novice in electronics, and I greatly appreciate all of the effort and time you're expending in posting.

A bit off topic: You wouldn't happen to have a suggestion for an entry-level multimeter, would you? I've been following EEVblog on YouTube for a while, and have learned a lot from it. I've been leaning toward an <a href="http://www.youtube.com/watch?v=bKvyoZa5J8Q" target="_blank">Agilent U1272A or a Fluke 87 V</a> <img src="../scipics/_yt.png" /> (admittedly beyond entry-level, but I'm willing to invest once I find employment).

I'm re-watching these:
<a href="http://www.youtube.com/watch?v=gh1n_ELmpFI" target="_blank">EEVblog #75 - Digital Multimeter Buying Guide for Beginners</a> <img src="../scipics/_yt.png" />
<a href="http://www.youtube.com/watch?v=ZoeUgMFLyAw" target="_blank">EEVblog #91 - $50 Multimeter Shootout - Extech EX330, Amprobe AM220, Elenco, Vichy VC99, GS Pro-50</a> <img src="../scipics/_yt.png" />
<a href="http://www.youtube.com/watch?v=n3WGaiYF2sk" target="_blank">EEVblog #99 - $100 Multimeter Shootout - Extech Amprobe BK Precision Ideal UEi Uni-T</a> <img src="../scipics/_yt.png" />

[Edited on 3.9.13 by bfesser]

IrC - 3-9-2013 at 12:53

I have dozens of DVM's in boxes. Only Flukes stay on my bench.

Plutonium239 - 3-9-2013 at 13:41

I was aware of the cheap Russian tubes on eBay, but I never considered assembling my own neutron detector with them. Is a moderator required? I know that fast neutrons are less likely to interact with particles, so should the tube be surrounded with borated paraffin? But then I would assume that neutrons produced by bombarding beryllium with alpha particles are mostly in the thermal range, so I kind of doubt that it would even be needed for this application.

IrC - 3-9-2013 at 13:43

Yes you need a moderator.

For Neutrons to test it build this: Electron beam driven neutron generator

http://www.freepatentsonline.com/3968378.html

[Edited on 9-4-2013 by IrC]

Marvin - 7-9-2013 at 14:24

Quote: Originally posted by IrC

http://www.freepatentsonline.com/3968378.html
[Edited on 9-4-2013 by IrC]

Has anyone actually made one? It looks tricky, assuming the principle works at all.

IrC - 7-9-2013 at 16:06

I would guess if they did it would have been at Los Alamos or somewhere with an advanced lab.

12AX7 - 7-9-2013 at 23:27

Easy:
http://www.electricalfun.com/WorkbenchFun/Fusor_William_Jack...

Though it didn't turn up in the first hits, I recall a webpage concerning amateur fusion efforts, with several examples needing only a source of deuterium and tritium to generate neutrons.

Unfortunately, none of these are anywhere near overunity -- thermalization in the middle prevents desirable head-on collisions for the most part. They can be used as portable neutron sources though.

Tim

phlogiston - 8-9-2013 at 05:06

bfesser, also consider that the resistance of the circuit board material becomes relevant when working with such high resistances. I used a 10Gohm resistor to built a fast pico-ampere amplifier for use as a headstage in electrophysiology experiments (for recording the electrical activity of single ion channels), and could not get it to work satisfactorily untill I built the critical part of the circuit in 'dead-bug style'

bfesser - 8-9-2013 at 06:14

Thanks, phlogiston, I had planned to <a href="http://runawaybrainz.blogspot.co.uk/2012/04/audio-crystal-cmoy-freeform-headphone.html" target="_blank">freeform</a> <img src="../scipics/_ext.png" /> or <a href="http://en.wikipedia.org/wiki/Point-to-point_construction#.22Dead_bug.22_construction" target="_blank">dead-bug</a> <img src="../scipics/_wiki.png" /> it. The project is on hold until I can afford a decent multimeter.

Marvin - 8-9-2013 at 08:53

To use a fusor as a source of neutrons you don't need tritium, just deuterium. It's a large project on it's own. The glass mockup "demo fusors" are not capable of neutron production, glass does not survive a proper run and a really good flowing vacuum system is required. fusor.net is the place to go for more information.

IrC - 10-9-2013 at 11:17

http://techlib.com/science/ion.html

Wanted to add this link but forgot where it was. Been a while since I went to this site. Anyway here it is. I have built everything on the page at one time or another. Maybe bfesser will find a project He likes. Or :

http://www.vk2zay.net/article/265

http://circuitsalad.com/2012/11/19/a-solid-state-photodiode-...

http://www.techlib.com/science/ionchamber.htm

bfesser - 10-9-2013 at 14:23

Great links, IrC. Thank you for sharing these. I especially like the techlib.com pages. I saw a similar page once on soup can ionization chambers, but can't recall where I bookmarked it.

IrC - 10-9-2013 at 17:46

I wanted to add the link to http://techlib.com long ago but could not remember the name and there are no embedded keywords that I could see to aid search engines. I was looking at a Polonium pen I made a while ago and just could not remember where I found the plans for it. Oddly I was searching for picoamp photodiode amplifier circuits for a gamma detector I was playing with and serendipitously one of the pages I found had a link to techlib. I recognized the name the instant I saw it and just had to come back here and post it. Besides one of the most useful tools I ever built was the C-Beeper which I also found on the site.

http://www.techlib.com/electronics/c_beeper.html

A guy running a cat digging a trench outside my building chopped a business line main cable (pulled about 100 feet of 100 conductor line out of the ground, ripping it out leaving the end nearest me hidden underground). The phone company would not be able to fix it for 11 days as it was going to be a major dig up a trench 400 feet to a junction box. No phone, no DSL, no internet. Phone no biggie people bother me anyway at the worst times. No DSL? That was asking far too much. So I got the guy with the cat to help me measure out the stretch of cable, approximate where 3 feet down the end might be, and dig until we found it. 110 feet of 2 conductor wire later I patched my pair, leaving the wire just laying on the ground. Only 2 wires in the 100 active (only me here now the other businesses long gone). Trusty Fluke one probe in dirt, testing junction box end, two wires showed voltage. At my end inside using the C-Beeper it took mere seconds to find the right 2 wires.

Quote: Originally posted by Marvin

Quote: Originally posted by IrC

http://www.freepatentsonline.com/3968378.html
[Edited on 9-4-2013 by IrC]

Has anyone actually made one? It looks tricky, assuming the principle works at all.

I was going to comment on this the other day, then got busy and forgot about it. Has anyone studied the Krytron? I know, just a switch but years ago I remember studying a neutron pulse tube patent (if I recall the number I'll post it) which was very similar except a sudden pulse of current drove particles against an enriched LiD target deposited on a really thin Be window. In effect a Krytron type pulse assembly which directed a jet of particles at high velocity against a target designed to produce neutrons for use in the Teller-Ulam design. Been a few years and I don't recall the specifics, was it protons or Alpha particles, I will need to go find and study the patent again to be sure. In the meantime:

http://en.wikipedia.org/wiki/Neutron_generator

Or, what about building a Neutristor?

http://www.youtube.com/watch?v=fOsoueOIURo

http://arxiv.org/abs/1308.0327

Another page on neutron fun:

http://en.wikipedia.org/wiki/Neutron_source

Attachment: 1308.0327.pdf (206kB)
This file has been downloaded 923 times

[Edited on 9-11-2013 by IrC]

bfesser - 12-9-2013 at 06:16

I can't wait until the neutristor becomes an off-the-shelf component! I wonder how long it will take them to develop a similarly small and simple detector. Thanks for the links.

I finished a modification of my MightyOhm.com GC Kit last night and was going share my idea, but sadly the HV circuit died before I was able to test it. The modification was on the LV side, and shouldn't have caused the malfunction. I think I may have fried the FJN3303F while adjusting the HV, so I'm going to order some replacement parts from Mouser later today. Frustratingly, my multimeter died yesterday morning, so I can't even use that to diagnose the failure.

[edit] I just found some photos on my camera that I will share.

<table><tr><td>

</td><td>

</td><td>

</td></tr><tr><td></td><td></td><td>

</td></tr></table>

On the left is a close-up of the counter with an SBM-20 G–M tube and NiMH batteries installed. A cable is attached from the serial header to a <a href="http://adafru.it/757" target="_blank">level shifter</a> <img src="../scipics/_ext.png" />, shown clearly in the second photo. I had the <a href="http://arduino.cc/en/Main/arduinoBoardUno" target="_blank">Arduino Uno</a> <img src="../scipics/_ext.png" /> set up to relay the serial through USB to my laptop. In the third photo, you can see a prototype hardware interface which allows monitoring of the pulse output of the kit in GeigerBot on an iPhone (below is a wiring diagram, adapted from <a href="https://sites.google.com/site/diygeigercounter/geiger-bot-interface" target="_blank">here</a> <img src="../scipics/_ext.png" />

. Inside the tote were a pair of thorium lantern mantles and my torbernite & trinitite specimens.

Note Regarding Arduino Serial:
Here's a nifty trick for anyone with an Uno but without a PC serial port or FTDI: Put a jumper between "RESET" and "GND" on the UNO and any (3.3-5V) serial data fed to "TX → 1" will be relayed through USB to your computer. You can easily view the data using the <a href="http://arduino.cc/en/Guide/Environment#serialmonitor" target="_blank">Arduino IDE Serial Monitor</a>, or capture it using <a href="http://realterm.sourceforge.net/" target="_blank">RealTerm</a> <img src="../scipics/_ext.png" /> or a similar application.

Final Notes:
The modification I made was to include the interface circuit on a daughter-board inside the counter case. I'll try to post photos and an explanation tomorrow. You can also connect the kit to a computer using any 3.3V compatible <a href="http://adafru.it/70" target="_blank">FTDI cable</a> <img src="../scipics/_ext.png" /> or breakout. I recommend the <a href="adafru.it/284" target="_blank">FTDI Friend</a> <img src="../scipics/_ext.png" /> by Adafruit, but others are available (<a href="https://www.sparkfun.com/products/9873" target="_blank">SparkFun</a> <img src="../scipics/_ext.png" /> {mixed reviews}, <a href="http://thecustomgeek.com/store/products/ftdi-ez-flex-adapter/" target="_blank">TheCustomGeek.com</a> <img src="../scipics/_ext.png" /> {out of stock}). The MightyOhm.com Geiger Counter Kit can also be purchased <a href="http://adafru.it/483" target="_blank">from Adafruit</a> <img src="../scipics/_ext.png" />, as well as <a href="http://adafru.it/561" target="_blank">the case</a> <img src="../scipics/_ext.png" />. If you watch their <a href="http://www.youtube.com/playlist?list=PL7AE4BFB81D3DC925" target="_blank">Ask an Engineer</a> <img src="../scipics/_yt.png" /> webcast on Saturday evenings at 10:00 p.m. EST (UTC-5), you can get a promotional code for 10% off. The kit+tube+case is currently on sale for 99.95 USD <a href="http://mightyohm.com/blog/products/geiger-counter/" target="_blank">from MightyOhm.com</a> <img src="../scipics/_ext.png" />. You do the math.

[2nd edit] I used one of the cables from <a href="http://www.radioshack.com/product/index.jsp?productId=10797999" target="_blank">this RadioShack product</a> <img src="../scipics/_wiki.png" /> for connecting the 3.5mm TRS socket on the prototype to the 3.5mm <a href="http://en.wikipedia.org/wiki/Phone_connector_(audio)#TRRS_Standards" target="_blank">TRRS</a> <img src="../scipics/_wiki.png" /> iPhone jack—no clue as to the intended purpose, it was the cheapest I could find locally. My recently deceased multimeter's continuity test function was used to verify the internal wiring (see diagram above).

[Edited on 13.9.13 by bfesser]

bfesser - 13-9-2013 at 17:00

Quote: Originally posted by bfesser

I finished a modification of my MightyOhm.com GC Kit last night and was going share my idea, but sadly the HV circuit died before I was able to test it. The modification was on the LV side, and shouldn't have caused the malfunction. I think I may have fried the FJN3303F while adjusting the HV, so I'm going to order some replacement parts from Mouser later today. Frustratingly, my multimeter died yesterday morning, so I can't even use that to diagnose the failure.

Not that anyone but myself actually cares, but I got the kit working again. On a hunch (call it <a href="http://www.youtube.com/watch?v=g8vHhgh6oM0" target="_blank">'the knack'</a> <img src="../scipics/_yt.png" />

, I replaced the 2n3904 on the HV side with the last one I had in my parts boxes, and it worked. I'm too tired to do a write up tonight, but here's a preview (turn your volume down):

<iframe sandbox width="420" height="315" src="//www.youtube-nocookie.com/embed/4gqPfqamrtA?rel=0" frameborder="0" allowfullscreen></iframe>

dontasker - 14-9-2013 at 18:55

Just thought I'd throw this out there. Found it while browsing hackaday. It's Arduino based, has a solid state detector, and color touch-screen display.

@bfesser
Looking forward to the write up!

IrC - 18-9-2013 at 20:21

Bfesser it occurs to me to ask was the 3904 and your new meter dying related? As in a HV spike while checking voltages. No doubt the meter did not come with a schematic but it may be possible to save it. I have blown several of my Flukes multiple times over the years, especially in my Tesla Coil days. Every time I have managed to revive the meters by studying board and learning the locations of spike protection devices. Pulling one end loose would bring back the voltmeter function. If that worked then replacing with a similar device. On those occasions the meter would still work in current ranges so at least I knew the processor and A-D portions were OK. You might take it apart and look for parts from the voltage probe input to ground and testing for short circuit. At least worth some study time and educated guessing as opposed to just chucking it in the hacker supply bin. Also find something with a higher voltage rating than the 3904.

[Edited on 9-19-2013 by IrC]

bfesser - 18-9-2013 at 22:20

Unrelated. The meter just blew a 500 mA fuse while I was trying to get a reading on the current draw of my vacuum pump. The only thing still non-functional on it is the 'high-current' function (unfused). I don't recall it ever working, now that I think about it...

IrC - 19-9-2013 at 04:09

Is there a circuit path of low impedance in high current range, i.e., a device functions just no reading? Does it display zeros? Maybe an omitted part or cold solder junction in meter? Or if you take the meter apart and study the range switch do you see thick black oxide on contacts? You might try spraying an electronic grade of cleaner/lubricant on the contacts while rotating the switch. Then spraying the board with Hexane such as CRC QD electronic cleaner (Walmart) to get rid of oily residue.

bfesser - 21-9-2013 at 16:05

IrC, I've been a bit distracted from it for the last week, but I'll take another look at it.

<hr width="80%" />
I stopped at the same antique shop (where I found the 'hot plate') today, and picked up a small "depression era" shot glass. The glass is quite thin, and a strangely pleasing light green color. It's slightly radioactive (CPM noticeably elevated above background—no quantitative data). Here are two photos; the first under standard illumination, and the second directly under my 254 nm UV lamp:

[edit] It's 48 mm in height and 39 mm max. OD—feels smaller than most shot glasses I've held. I might drink from it... but just once.

<a href="https://en.wikipedia.org/wiki/Depression_glass" target="_blank">Depression glass</a> <img src="../scipics/_wiki.png" />
<a href="https://en.wikipedia.org/wiki/Uranium_glass" target="_blank">Uranium glass</a> <img src="../scipics/_wiki.png" />

[Edited on 22.9.13 by bfesser]

plante1999 - 20-10-2013 at 17:39

So, bfesser, have you found some ore, or looked for them?

Or you are more of the shop guy, looking in stores for already gathered stuff?

Looking forward devlopement.

bfesser - 21-10-2013 at 11:56

Well, for rocks and minerals, I much prefer to find them myself, but I live between two metropolitan centers, and there's not much uncovered ground. Even if the land weren't developed, I live on a thick layer of glacial till over some unremarkable dolostone. I've been scouting at the local rock & mineral shows, but haven't found anything worth posting yet. I was hoping to go to the Black Hills and Bighorn Mountains this fall, but it looks like the plans will be delayed until next year.

IrC - 21-10-2013 at 23:11

http://www.imagesco.com/articles/articleindex.html

This site has a Geiger counter project and a few interesting things to study:

http://www.imagesco.com/articles/geiger/build_your_own_geige...

They also sell sources to test your counter with:

http://www.imagesco.com/geiger/uranium-ore.html

http://www.imagesco.com/geiger/radioactive-sources.html

They also have a graph for Cs137:

[Edited on 10-22-2013 by IrC]

bfesser - 4-11-2013 at 15:23

Testing out a thrift shop scanner, thought I'd share these in case anyone's interested:

Fenir - 4-11-2013 at 18:49

How much did you pay for the two? It looks like you got a survey meter instead of a Geiger counter. The survey meter is essentially useless unless you live in Prypiat. However the dosimeter looks quite diverting.

bfesser - 5-11-2013 at 05:24

The instructions are indeed from a surplus Civil Defense survey meter kit; intended for high levels of γ radiation.

Just finished a geiger kit

BobD1001 - 30-11-2013 at 14:16

I recently purchased another type of Geiger kit through trough the DIYgeigercounter site. I had compared it to the MightyOhm kit and decided to go with the DIYgeiger counter as it was virtually the same price and seems to have a little more flexibility in tubes to drive and accessories to use with it; but mostly just because it looked more challenging to solder

.

After completing the kit, it works fantastically, and I hope to be able to find some samples of uranium ore for my periodic table display from a local abandoned copper/silver/lead mine. I am going to be running two SBM-20 tubes in parallel for enhanced sensitivity, although I would love to get a pancake type tube.

Here are some pictures of the build:

And here is a shot of it up and running with the two SBM-20's in parallel. The source is a thorium lantern mantle I got off eBay for a few bucks.

SL-1 & SRE

bfesser - 5-12-2013 at 14:33

Very nice. I've been thinking about trying one of those kits. I'm curious, though; with the additional SBM-20, have you adjusted the dose rate calculation accordingly?

[1st edit] I've modified the firmware on my mightyohm.com GC slightly. In short; I reduced the LED flash length slightly, added a third 'mode' which gives more traditional (nostalgic) 'clicks' on the Piezo—rather than the louder 'chirps'—and set it to default to the click mode when first powered on and cycle through click-chirp-mute when the button is pressed. I haven't cleaned up, optimized, or commented the code yet. Consider this to be a beta firmware mod.

Attachment: geiger_mod.tar.gz (18kB)
This file has been downloaded 1053 times

In a future version, I plan to adjust the dose rate calculation, among other things.

[2nd edit] <a href="http://en.wikipedia.org/wiki/SL-1" target="_blank">Stationary Low-Power Reactor Number One (SL-1)</a> <img src="../scipics/_wiki.png" />

<iframe sandbox width="420" height="315" src="//www.youtube-nocookie.com/embed/FAKcWM-yBkI?rel=0" frameborder="0" allowfullscreen></iframe>

<a href="http://en.wikipedia.org/wiki/Sodium_Reactor_Experiment" target="_blank">Sodium Reactor Experiment (SRE)</a> <img src="../scipics/_wiki.png" />

<iframe sandbox width="420" height="315" src="//www.youtube-nocookie.com/embed/videoseries?list=PLH27cxqYTgN52BtiAPv49_o_quNR_M8ea" frameborder="0" allowfullscreen></iframe>

[Edited on 16.12.13 by bfesser]

IrC - 5-12-2013 at 16:03

I don't see any links to the site the kit came from. On it is a handy page of info to aid in calibrating the GM tubes.

https://sites.google.com/site/diygeigercounter/gm-tubes-supp...

Chernobyl Catastrophe

bfesser - 16-12-2013 at 13:12

Some documentaries about the <a href="http://en.wikipedia.org/wiki/Chernobyl_disaster" target="_blank">Chernobyl disaster</a> <img src="../scipics/_wiki.png" /> on YouTube (chronological order):
<a href="http://youtu.be/e3FjkBozlu0?t=33s" target="_blank">NOVA: Back to Chernobyl</a> <img src="../scipics/_yt.png" /> (1989)
<a href="http://youtu.be/VDvCoLEpB0c" target="_blank">NOVA: Suicide Mission to Chernobyl</a> <img src="../scipics/_yt.png" /> (1991)
<a href="http://youtu.be/hUAATawYCD8" target="_blank">Horizon: Inside Chernobyl Sarcophagus</a> <img src="../scipics/_yt.png" /> (1991)
<a href="http://youtu.be/_TQ32XV0B54" target="_blank">Horizon: Fallout from Chernobyl</a> <img src="../scipics/_yt.png" /> (1996)
<a href="http://youtu.be/pNvmShXD0vw" target="_blank">Zero Hour: Disaster at Chernobyl</a> <img src="../scipics/_yt.png" /> (2004)
<a href="http://youtu.be/5WGUbfzr31s" target="_blank">Seconds From Disaster: Meltdown at Chernobyl</a> <img src="../scipics/_yt.png" /> (2004)
<a href="http://youtu.be/3Q7w17VSqTM" target="_blank">The Battle for Chernobyl</a> <img src="../scipics/_yt.png" /> (2006)
<a href="http://youtu.be/SYU47v_J9fo" target="_blank">Horizon: Nuclear Nightmares</a> <img src="../scipics/_yt.png" /> (2006)
<a href="http://youtu.be/YfulqRdDbsg" target="_blank">Inside Chernobyl</a> <img src="../scipics/_yt.png" /> (2012)

These are the highest quality uploads I could find. For Meltodown at Chernobyl, there is another version available <a href="http://youtu.be/lyqpVOxmw8s" target="_blank">with an American narrator</a> <img src="../scipics/_yt.png" />, but he's annoying and the video quality is reduced. Please let me know if any of the videos are removed, and I'll try to find another copy. I will be compiling and posting similar collections of videos for both Three Mile Island, Windscale, and Fukushima as I find time. Or, if you like, you can follow <a href="http://www.youtube.com/playlist?list=PLH27cxqYTgN7XnLn1zz1Ea7htguJBe1b3" target="_blank">this playlist</a> <img src="../scipics/_yt.png" /> where I'll be adding videos as I find them.

[Edited on 17.12.13 by bfesser]

dontasker - 16-12-2013 at 19:03

Looking at the list of videos made me think of:
BBC Horizon: Nuclear Nightmares
_{Video hosted on DailyMotion}

BobD1001 - 16-12-2013 at 19:59

Quote: Originally posted by bfesser

Very nice. I've been thinking about trying one of those kits. I'm curious, though; with the additional SBM-20, have you adjusted the dose rate calculation accordingly?

I haven't yet adjusted the dose rate to compensate for running the two tubes in parallel. I'm not really all that concerned as I'm really just going to be using the counter to hopefully find some samples of ore for my element collection. In the future if I do any logging or that sort of thing, I will adjust the code to compensate for it.

I really want to get one of the GPS modules, and log the average counts according to location, as I live somewhat near an active nuclear power plant. Of course I wouldn't expect to see any above average values near the plant, as its never had an incident, but it would be neat to try just out of curiosity. The site has a good writeup of it here: https://sites.google.com/site/diygeigercounter/daughterboard... It would be be a neat experiment, just no extra funds to do it!

[Edited on 17-12-2013 by BobD1001]

bfesser - 17-12-2013 at 05:45

It's interesting to note that radiation levels are typically higher near coal power plants than nuclear ones (<a href="http://en.wikipedia.org/wiki/Fossil-fuel_power_station#Radioactive_trace_elements" target="_blank">ref.</a> <img src="../scipics/_wiki.png" />

. Luckily for me, there are plenty of each in my area, including 3 nuclear plants—some decommissioned, but much of the pollution remains.

For GPS, I'd recommend the <a href="http://www.adafruit.com/products/746" target="_blank">Adafruit Ultimate GPS Breakout</a> <img src="../scipics/_ext.png" />. They've also got it available as an Arduino shield, a wearable breakout, and a bare module. Sparkfun has some <a href="https://www.sparkfun.com/categories/4" target="_blank">GPS receivers and modules</a> <img src="../scipics/_ext.png" /> as well. Finally, you'll want to familiarize yourself with <a href="http://en.wikipedia.org/wiki/NMEA_0183" target="_blank">NMEA 0183</a> <img src="../scipics/_wiki.png" />.

[Edited on 17.12.13 by bfesser]

Solid-state Gamma Detection with PIN Photodiodes

bfesser - 3-1-2014 at 09:00

The title pretty much sums it up. Not much to say, except that I'll be checking between the couch cushions for change to order some <a href="http://www.mouser.com/ProductDetail/OSRAM-Opto-Semiconductors/BPW-34/?qs=sGAEpiMZZMtWNtIk7yMEsZEKXNTNxzvbiGrwFlDOnN8%3d" target="_blank">BPW34</a> <img src="../scipics/_ext.png" /> <a href="http://en.wikipedia.org/wiki/PIN_diode" target="_blank">PIN</a> <img src="../scipics/_wiki.png" /> <a href="http://en.wikipedia.org/wiki/Photodiode" target="_blank">photodiodes</a> <img src="../scipics/_wiki.png" /> for experimenting with <a href="http://en.wikipedia.org/wiki/Solid-state_(electronics)" target="_blank">solid-state</a> <img src="../scipics/_wiki.png" /> <a href="http://en.wikipedia.org/wiki/Gamma_ray" target="_blank">gamma ray</a> <img src="../scipics/_wiki.png" /> detection.

Here are the better of the websites I've been looking at (sorry, my favorite are in German):
<a href="http://www.b-kainka.de/bastel131.html" target="_blank">Das Gammastrahlen-Mikrofon</a> <img src="../scipics/_ext.png" /> (b-kainka.de) ~ "The gamma-ray Microphone"
<a href="http://www.elektronik-labor.de/Projekte/Gamma3.html" target="_blank">Der Gammadetektor III</a> <img src="../scipics/_ext.png" /> (b-kainka.de) ~ "The gamma detector III"
<a href="http://www.elektronik-labor.de/Projekte/Alpha5.html" target="_blank">Kernstrahlungs-Spektrometer</a> <img src="../scipics/_ext.png" /> (b-kainka.de) ~ "Nuclear radiation spectrometers"
<a href="http://www.vk2zay.net/article/265" target="_blank">Photodiode Gamma Ray Detector</a> <img src="../scipics/_ext.png" /> (Alan's Lab)
<a href="http://www.dgkelectronics.com/a-radiation-detector-with-a-solid-state-pin-diode-sensor/" target="_blank">A radiation detector with a solid-state PIN-diode sensor</a> <img src="../scipics/_ext.png" /> (DGK Electronics)

I'll upload all the PDFs I've collected:
<table><tr><td>Application circuit examples of Si photodiode      Hamamatsu Photonics (appnote)</td><td>Attachment: appnote_Hamamatsu.pdf (64kB)
This file has been downloaded 1168 times</td></tr><tr><td>Gamma-Photon Radiation Detector      Maxim Integrated (appnote)</td><td>Attachment: appnote_Maxim.pdf (78kB)
This file has been downloaded 1119 times</td></tr><tr><td>Silicon PIN Photodiode: BPX 61      Osram Opto Semi. (datasheet)</td><td>Attachment: datasheet_bpx61.pdf (192kB)
This file has been downloaded 1179 times</td></tr><tr><td>Si PIN photodiodes: S1223 series      Hamamatsu Photonics (datasheet)</td><td>Attachment: datasheet_s1223.pdf (615kB)
This file has been downloaded 981 times</td></tr><tr><td>PIN Photodiode Based X and γ Ray Detectors      E. Emirhan & C.S. Ozben</td><td>Attachment: Emirhan_Ozben.pdf (954kB)
This file has been downloaded 3319 times</td></tr><tr><td>Measure Gamma Rays with a Photodiode: Radiation detector using a BPW34      B. Kainka</td><td valign="top">Attachment: Kainka.pdf (531kB)
This file has been downloaded 9316 times</td></tr><tr><td>Gamma-Ray Detectors      H.A. Smith Jr. & M. Lucas</td><td>Attachment: Smith_Lucas.pdf (1.2MB)
This file has been downloaded 1579 times</td></tr><tr><td>An Intro. to Semiconductor Radiation Detectors      C.W. Thiel</td><td>Attachment: Thiel.pdf (1.3MB)
This file has been downloaded 1890 times</td></tr></table>

[Edited on 6.1.14 by bfesser]

IrC - 3-1-2014 at 22:43

"sorry, my favorite are in German"

Another site : http://www.rapp-instruments.de/

bfesser - 5-1-2014 at 17:56

<iframe sandbox width="560" height="315" src="//www.youtube-nocookie.com/embed/zMDUzDBzFD8?rel=0" frameborder="0" allowfullscreen></iframe>

<a href="http://www.teviso.com/" target="_blank">TEVISO Sensor Technologies Ltd.</a> <img src="../scipics/_ext.png" />

neptunium - 6-1-2014 at 19:13

the technology is getting better and better with every new breakthrough in electronics! what used to betens of thousands of dollars of investments and constant supply of liquid nitrogen when i was studying nuclear physics 15 years ago is now availlable for hundreds! and no cooling !
i wonder how far these diodes can go...
the videos doesnt explain what type of display device and compatibility those semi conductors work with ... shame

also check out this video...

http://www.youtube.com/watch?v=BRdZouC7CRo

i think he gets it arround exit 79 on I40 in new Mexico for anyone familiar with the area

[Edited on 7-1-2014 by neptunium]

IrC - 6-1-2014 at 23:46

Yeah I used to pick up good Carnotite rocks north of what is now Sky City Casino a little ways past Grants. That would put it more like the 89 mile marker or thereabouts. However look east to Santa Rosa, go up a main gravel road a few miles north of town. Bring a few pickup trucks as you can find a ton of several different species, my favorite for high rad levels being Coffinite. Real hard to find anywhere else by the way except at a few locations in Colorado. This location was big decades ago but not well liked by the people there. I knew a few families who lost their providers working to mine Uranium and IIRC Radium. No safety procedures at all. Pretty much the company had workers hands on with the rocks with virtually zero protection. From the stories one lady friend in particular had the company didn't seem to care much if workers died from terrible cancers as her husband did. Think of the 40's and 50's and coal miner stories, but add high levels of radiation much of which was breathed in daily in dust by the workers. By the 70's it was mostly all closed down and played out. You can find more specimens by the tons in tailing piles than you would ever want to haul away.

bfesser - 7-1-2014 at 06:33

IrC, that sounds like heaven to me. I'll have to mark it on my maps.

neptunium, that techniques in that video always make me cringe.

IrC - 7-1-2014 at 10:21

Quote: Originally posted by bfesser

IrC, that sounds like heaven to me. I'll have to mark it on my maps.

neptunium, that techniques in that video always make me cringe.

If really hot specimens is your goal I'll give you a better place. Picture this. All day I am marveling at the weirdest saguaro cactus I have ever seen. A large arm goes up as is normal, halfway up the arm is another arm coming out growing down. Like one cactus sticking out of another but it naturally grew that way, a single cactus. Many like it or even stranger looking, especially odd looking prickly pear everywhere you look. Warm night so I put the campfire out after making coffee. Getting used to the dark lying there looking at an amazingly rich field of stars. But I keep noticing a strange very dim blue glow all around, especially coming from the dry creek bed. Before any physics majors come in saying that's not possible my reply is I saw it with my own eyes. That trip I was prospecting from experience along with my trusty mineral book and chemical kit, last time in Phoenix no one had any 'B' batteries in stock so my Precision 111B sat in the trunk dead as a hammer. I had nothing to detect radiation with.

image3501.jpg - 5kB

Next day I study the area and in the middle of the dry creek, a smooth bedrock surface, I notice thousands of jet black botryoidal bumps in the rock. You guessed it, Uraninite. With the highest concentration of Radium I have ever found.

http://national-radiation-instrument-catalog.com/Image170.gi...

http://upload.wikimedia.org/wikipedia/commons/e/e7/Pitchblen...

Spent a few days with hammer and chisel filling a backpack so full it was hard to carry even on my back. Took it back down to *a place* where it could be measured in Phoenix as I had no way to test for radioactivity. As luck would have it the transmission went out of my car, 1975, dead economy few jobs so it took a while to fix my car and outfit for a trip back to stake a claim. A large company claimed it before I returned and ran a mine there for several years. I know without doubt *this person* had friends in the business and of course I had stupidly told him exactly where it was.

Years later they restored the natural look to the place but believe me there is still a huge amount there as I had found outcrops in over a mile in any direction. I bring all this up because if you really want to go out and add to your collection the hottest rocks you will ever find in the US is there. I know this because 8 months later the Arizona Republic had a front page pic of my campsite with the headline "largest Uranium and Radium discovery in US history". True story.

A little way north of the Grand Canyon, 20 miles southwest of Fredonia Arizona is a box canyon called Hacks Canyon. Dry dead for eons stream bed, the very one I filled my pack in. You should make a trip this summer and bring your counters, pick and other tools. Would be well worth the trip even after the mining closed down so long ago. I know it's worth your trip because to this day you can see the blue glow all around, just search for the most deformed freaking odd cactus you have ever seen. It occurs in patches here and there for a mile in diameter, they only mined the creek bed. Wherever you see patches of deformed cacti you have only a few inches to dig to bedrock to see the formations of black glowing grapes (at night).

First time I ever gave out my best location but I'm too old to ever go back so what the hell if some of you want to grab a great collection of specimens more power to you. While your there head south over Mt Trumbull (take a survey map it's gravel roads through wilderness) and visit the North rim of the Grand Canyon. They may be paved now it's been been nearly 40 years since my last trip there. Or go back out to the highway to get there. By far the greatest place to see it from, without all the endless lines of tourists, they nearly all visit the site from the south rim.

**Occurs to me mentioning the location, year, and job position of the one who gave out my find location could make it simple to get a name and open possible liability for myself and SCM. Being almost 4 decades ago I can not prove it even if there was no other possible source that could have sold the information. Long ago loss may as well be safe and keep identities obscure.

[Edited on 1-7-2014 by IrC]

bfesser - 7-1-2014 at 11:10

Damn. I just missed an auction for a mint condition <a href="http://www.orau.org/ptp/collection/surveymeters/precisiondeluxe.htm" target="_blank">Precision 111</a> <img src="../scipics/_ext.png" /> on eBay a couple months ago. I'm still mad at myself for not selling a kidney to get it—I think it went for only around 40 USD. Unfortunately, I'm broke as all hell, and surely won't be able to come up with funds or transportation from the MN tundra all the way to the AZ desert. I'll certainly take note of the location, though, and will try to find some geologic maps of the area.

[Edited on 7.1.14 by bfesser]

Fireball and blastwave from Grable nuclear detonation

Dany - 7-1-2014 at 15:24

Very beautiful video of the explosion of a nuclear shell at low altitude, fired from nuclear cannon (280 mm). the test name is Grable (1953) and shows the effect of an explosion of a low altitude nuclear device. The device in the form of a shell uses the gun type mechanism (same as Little boy-Hiroshima) to detonate the warheads. The intense shock wave from the warheads will reflect when touch the ground, and after a short time it fuses with the incident shock wave so as to form a Mach wave which can have twice peak pressure as that of incident wave. The Mach wave can inflict extensive damage when interacting with object in it's path.

Grable test (1953)

Dany.

violet sin - 7-1-2014 at 15:58

impressive, thanks for sharing. that was well restored and beautiful even in full-screen

ExcelPhysics APOC Mini Radiation Detector

bfesser - 9-1-2014 at 11:52

While browsing around, I found this reasonably-priced <a href="http://excelphysics.com/collections/apoc-detector/products/apoc-basic-kit" target="_blank">gamma detector kit</a> <img src="../scipics/_ext.png" /> based on an array of seven BPW34 PIN photodiodes in parallel and an LM311 comparator. I'm working on designing my own small BPW34-based detector, which I hope to enclose in a small aluminum flashlight housing, but this kit is very tempting. The sellers also carry the <a href="http://excelphysics.com/collections/frontpage/products/apoc-basic-kit-no-enclosure" target="_blank">kit sans-enclosure</a> <img src="../scipics/_ext.png" /> and what appear to be homemade 10n<a href="http://en.wikipedia.org/wiki/Curie" target="_blank">Ci</a> <img src="../scipics/_wiki.png" /> <a href="http://en.wikipedia.org/wiki/Isotopes_of_thorium#Thorium-232" target="_blank">232Th</a> <img src="../scipics/_wiki.png" /> <a href="http://excelphysics.com/collections/frontpage/products/confirmation-source-disk" target="_blank">check sources</a> <img src="../scipics/_ext.png" />.

<img src="http://cdn.shopify.com/s/files/1/0223/5841/products/APOC_Basic_1024x1024.jpg" height="200" /> <img src="http://cdn.shopify.com/s/files/1/0223/5841/products/Finished_Top_No_Tape_grande_1024x1024.jpg" height="200" /> <img src="http://cdn.shopify.com/s/files/1/0223/5841/products/Confirmation_Disk_1024x1024.jpg" height="200" />

While I can't vouch for it (yet), this kit might be an option for those who cannot purchase the MightyOhm kit due to import/export restrictions.

Attachment: LM311_datasheet.pdf (1.1MB)
This file has been downloaded 874 times

[edit] Evidently they had a successful <a href="http://www.kickstarter.com/projects/excelphysics/apoc-mini-radiation-detector" target="_blank">KickStarter</a> <img src="../scipics/_ext.png" /> campaign early last year, and will be developing a more advanced unit with an integrated <a href="http://www.parallax.com/microcontrollers/propeller" target="_blank">Propeller</a> <img src="../scipics/_ext.png" /> microcontroller.

[Edited on 9.1.14 by bfesser]

neptunium - 9-1-2014 at 11:57

thanks for this fascinating story Irc ! i will have to plan one of my trips there this summer! however because of new regulations and radiation detectors at weigh stations there is a radiological limit to how much ore one can haul away... ha the good old days pre 9/11

bfesser - 9-1-2014 at 13:19

Quote: Originally posted by neptunium

i will have to plan one of my trips there this summer!

Any chance you want to swing by the Twin Cities (Minnesota) or Des Moines to pick up a hitchhiker along the way? An extra set of eyes and strong shoulders never hurt when prospecting or rock hunting.

Although I suppose the shortest land route for you would be through Indianapolis, St. Louis, Oklahoma City, and Albuquerque.

[edit] Re. IrC's first-hand observations:
<a href="http://en.wikipedia.org/wiki/Botanical_prospecting_for_uranium" target="_blank">Botanical Uranium Prospecting</a> <img src="../scipics/_wiki.png" />
<a href="viewthread.php?tid=17295">Radium glow</a>

[Edited on 9.1.14 by bfesser]

IrC - 9-1-2014 at 13:58

Quote: Originally posted by neptunium

thanks for this fascinating story Irc ! i will have to plan one of my trips there this summer! however because of new regulations and radiation detectors at weigh stations there is a radiological limit to how much ore one can haul away... ha the good old days pre 9/11

Load the crap out of your truck. From Fredonia 89 back towards Flagstaff. Halfway between turn left on 160 straight the F up, so steep it's damn near switchbacks, into Tuba City. Through the Navajo reservation on 160, bear left at Teec Nos Pos, don't go straight on the main drag that is 489 to Farmington New Mexico. You want to stay on 160. In fact you might want to hang out in the area for a while. I stayed on the Res for a while in the same year as the story above and the people were unbelievable. Anyway you will cross into NM for a very short stretch then into 160/491 into Colorado, drifting back east at Cortez. 160 east all the way across Kansas. Not sure where you are going back to but assuming you have a CB on channel 19 you can get info around every single weigh station there is. Besides I have never seen any laws relating to having mere rocks from the ground. Just don't go 40 miles east past Pagosa Springs if there is bad weather with ice anywhere, Wolf Creek Pass is one scary SOB if the road is bad.

Myself I would go the easy way and if they gave me crap at a weigh station (which you don't pull into anyway unless your GVW is over 26,000 pounds) if they gave me flak they would soon hear the many ways they could bite my shiny metal ass. Actually you could after Teec Nos Pos stay on 489, turn right at Farmington heading back down to I-40. At least this avoids the only thing cars and pickups do stop at, the agricultural inspection station on I-40 in Arizona before you get into New Mexico.

This is still America and we are still a free people no matter how anal retentive the DHS wishes to be and hauling your load of minerals you dig out of the ground is not illegal. Screw Em. If your really worried wrap lead sheet around your boxes of rocks.

I forgot to ask, what new regulations and how does this relate to minerals from a prospecting trip? Tell them you run a rock shop.

Also, I got the letter wrong. All this talk prompted me to go dig out my chrome beast and it's not a Precision 111B, change the B to a C. I also learned 2 things I had not considered in the talk in this thread. Found a link describing how much better the crystal is in my C than the B model. Honestly never read that before but back in those days we had no internet and finding things at a local library could be near impossible. Second, bfessers link. I never knew about looking at plant life actually being a tool for surveying deposits. I just found it out through experience by happening to camp on top of three mile Island's desert vacation spot. Looking at a cactus growing back out of a cactus. No pre knowledge of the subject (other than all the 'B' scifi in the 60's) yet it clicked in my mind after seeing the glow later that night that high radiation had to be the cause. That second day I started noticing the deformed patches of prickly pear and even though my scintillator had dead batteries I knew the area was hot. So much so I moved my campsite out of paranoia which is why I had to load a backpack with samples from the creek bed. I just was not comfortable sleeping on a perfect set for yet another stupid radioactive giant ants movie.

On another note neptunium if you do make a trip do us all a favor. I had no camera that trip. See if you can locate and photograph some of those scary looking deformed cacti. I suppose it's possible Exide found and dug up all the really hot spots but the area was so big. Surely if you do some hiking around there must be untouched places. This site was the largest I ever found in all the years out prospecting. Another question I have is can anyone explain the conditions where the Radium concentration is so much higher than typical pitchblende finds. I have Uraninite from various places in the southwest and I still have some of the rocks from this 1975 trip. 34 years later these rocks are still a hell of a lot hotter than various Uraninite rocks I have, much hotter than even my choice Coffinite specimens.

The area is very ancient volcanic, if you go straight south from this location to the north rim you will find a half mile wide stretch of nearly 100 percent Obsidian from the cliff top all the way down to the Colorado river. Standing there looking down at the river I kept having visions of being sliced into hamburger if I slipped and slid down that thing. Nothing but sharp shards of black glass, very frightening looking cheese grater. So is it possible deposits brought up in lava flows from deep in the earth concentrate Radium? Or was it merely the decay over eons of an unusually high percent per ton Uranium content?

On another note I just got a dozen BPW34's, bfesser do you have a schematic for your APOC kit? If you cannot post it does U2U allow files? I was going to build one using LMP7721's but looking at the part list yours looks simpler to build. Plus I have those parts in standard sizes meaning I could avoid dealing with surface mount components.

[Edited on 1-10-2014 by IrC]

neptunium - 9-1-2014 at 17:17

you were increadibly lucky Irc to find this spot its an amazing story ! the regulations i was mentioning are unworthy of this forum and concern commercial drivers (80 000lbs and up)
but i have found maps that indicates a hot area in Ohio (?) wich would be a lot closer to me (Michigan) and easier to haul away ... however i cannot pinpoint the exact location and the geology of this area doesnt look uranium ore prone.
having said that Uranium pops out of the ground like gold , a little bit everywhere..

i do agree with you on the freedom to pick rock out of the ground i just hate to see it confiscated because it triggered the detector i am not a confrontational dude especialy with the cops..

[Edited on 10-1-2014 by neptunium]

IrC - 9-1-2014 at 17:36

I don't think discussing the laws today are really off topic. The title is 'interest in radioactivity', and information about what we need to be concerned with actually going out and finding specimens seems pertinent. Pretty much this was how I looked at telling the story of my Hacks Canyon find, providing another great location for members serious about doing some digging for rocks. Myself I always try to avoid confrontations also but having done something like prospecting all my life I just do not think I would allow their unreasonable paranoia to stop me from going out and finding rocks to bring home. But that's just me.

I should add as with bfessers location, sedimentary deposits are fairly common so at least one could look for sandstone bearing Carnotite. Believe it or not there is a very hot location in black shale not too far from me and Arkansas is probably the last place I would go if looking for Uranium. Even though there is volcanic rocks down south this state is not known for much along these lines. I mention this anomaly since no doubt shale exists in your part of the country.

http://www.dangerouslaboratories.org/rak.html

The specimens there are very hot and it is more or less something one would not expect to be possible around here.

A good place to get ideas when planning your outings:

http://www.dangerouslaboratories.org/radrocks.html

I suppose it is up to bfesser if the last few posts are off topic, but to me it seems pertinent information to aid members who wish to go find some specimens to experiment with or test out their detector projects. Especially considering how much more expensive good specimens on ebay are getting. I also noticed United Nuclear which once was a decent source seems to eternally be sold out of everything, on top of being too pricey as well. At this point a nice 'working' summer vacation to go out and do some digging may well be worthwhile.

[Edited on 1-10-2014 by IrC]

bfesser - 9-1-2014 at 18:06

Quote: Originally posted by IrC

On another note I just got a dozen BPW34's, bfesser do you have a schematic for your APOC kit? If you cannot post it does U2U allow files?

I do not. I'm not sure if it was clear in my post, but I haven't (yet) purchased the kit. I have already started work on reverse-engineering the PCB to a schematic, based on the photos the <a href="http://excelphysics.com/" target="_blank">ExcelPhysics</a> <img src="../scipics/_ext.png" /> website. If I do purchase the kit, I'll scan and upload both sides of the unpopulated PCB—I don't see a screen printed copyright on the PCB, so screw 'em. And screw 'em again for not making it <a href="http://en.wikipedia.org/wiki/Open-source_hardware" target="_blank">OSHW</a> <img src="../scipics/_wiki.png" />!

Quote: Originally posted by IrC

I don't think discussing the laws today are really off topic. The title is 'interest in radioactivity', and information about what we need to be concerned with actually going out and finding specimens seems pertinent.
. . .
I suppose it is up to bfesser if the last few posts are off topic, but to me it seems pertinent information to aid members who wish to go find some specimens to experiment with or test out their detector projects.

I concur. This is exactly what I hoped to see in this topic, and why I tried to give it a rather generic subject line. Of course, the presence of this topic shouldn't be seen as a barrier to opening additional threads with specific foci.

As for sedimentary concentrations of radioactive minerals, I haven't found any in my locality—and I think they're highly unlikely in the particular sedimentary strata of my area. <del>I've found some dendritic manganite in the Decorah shale, but not much else.</del> [edit] (After looking through the specimens in my drawers, I found that I had been thinking of a specimen of manganese dendrites on dolostone from the Madison formation in Wyoming.) I've found nothing here but calcite and Ordovician marine fossils, but as soon as the mercury rises, I'll be out searching again.

[Edited on 10.1.14 by bfesser]

IrC - 9-1-2014 at 18:14

OK, done for a while anyway. Someone recently talked me into looking for my copy of THEM! and watching it. Been years since I saw that one.

Metacelsus - 9-1-2014 at 18:24

How much radiation does it take to actually cause a noticeable concentration of deformities in plants? It seems like said areas would be a severe health risk.

Side note:
I always am peeved by blatant violations of the square-cube relation (6 foot tall ants

).
Yes, I have seen THEM!

bfesser - 9-1-2014 at 18:34

Cheddite Cheese, I would guess that the effects are caused by the plants having actually incorporated significant quantities of radioisotopes through uptake of ground water—but I have yet to read more on the subject than the Wikipedia article.

Metacelsus - 9-1-2014 at 18:47

Yes, but anyone drinking water or eating food grown there would be at the same risk.

https://www.sciencedirect.com/science/journal/05315131/1276

(I was thinking more long-term health risks than short-term ones.)

[Edited on 10-1-2014 by Cheddite Cheese]

neptunium - 9-1-2014 at 19:02

Irc when i mentioned picking up a few rock i had a complete differente idea in mind. i collect element and also mess with nuclear physics a little... my idea is to chemicaly separate massive amount of ore to obtain significant amount of Radium, Thorium, and other uranium daughters.
so a dozen 5 gallons buckets fill with hot ore would hardly pass as a rock collection trip and would positively register on even the less sentitive detector . adding shielding would considerably increase the weigh of such load...
several trips would be required...
i find it so damn interesting i just cant help myself! the satifaction of accomplishing what Marie Curie did over 100 years ago is such an intelectual reward it over rides all risk and posible penalty! .... but thats just my dumbassand ...
also nature provide so much more than united nuclear!

neptunium - 9-1-2014 at 19:06

Quote: Originally posted by Cheddite Cheese

Yes, but anyone drinking water or eating food grown there would be at the same risk.

https://www.sciencedirect.com/science/journal/05315131/1276

(I was thinking more long-term health risks than short-term ones.)

[Edited on 10-1-2014 by Cheddite Cheese]

radiation is an everyday part of life at what point does it become dangerous is hard to say when it comes to natural radioactivity, not too many people live in the area mentioned above a few trips of 2 or 3 days per year would certainly not harm anyone (unless you eat the stuff and sleep with it )
as for the water supply contamination i would love to get my hands on a sample of water from the area and run it through my spectrometer..

IrC - 9-1-2014 at 19:12

Quote: Originally posted by neptunium

Irc when i mentioned picking up a few rock i had a complete differente idea in mind. i collect element and also mess with nuclear physics a little... my idea is to chemicaly separate massive amount of ore to obtain significant amount of Radium, Thorium, and other uranium daughters.
so a dozen 5 gallons buckets fill with hot ore would hardly pass as a rock collection trip and would positively register on even the less sentitive detector . adding shielding would considerably increase the weigh of such load...
several trips would be required...
i find it so damn interesting i just cant help myself! the satifaction of accomplishing what Marie Curie did over 100 years ago is such an intelectual reward it over rides all risk and posible penalty! .... but thats just my dumbassand ...
also nature provide so much more than united nuclear!

Having natural rocks for specimens is one thing, but trying to concentrate radioactive elements opens up a whole new realm of needing to be licensed since there are serious regulations involving this area. I could be incorrect I really never studied the subject of law on this (I study what I am interested in doing at the time and building a lab full of centrifuges has never been on the agenda), however I think this would not be a good idea for the amateur for many reasons. Never forget the price the Curie's paid for their curiosity, and you would have to deal with the NRC and DHS. Something which never existed in their day.

neptunium - 9-1-2014 at 19:24

very true Irc...this is probably going to remain a fantasy ...

bfesser check out this meter
http://www.ebay.com/itm/RPI-Rad-Monitor-Survey-Meter-DX-6000...

if i am not mistaken it is a scintillation probe ... often better and more sensitive than geiger tube

[Edited on 10-1-2014 by neptunium]

bfesser - 10-1-2014 at 06:36

Thanks for the link, neptunium, I've been wanting to build a <a href="http://en.wikipedia.org/wiki/Scintillator" target="_blank">scintillation detector</a> <img src="../scipics/_wiki.png" />, but they're invariably more expensive than the PIN photodiode-based designs—much more than I can afford at the moment.

<hr width="80%" />
I'll try to compile a list of radiation detector kits (online):
<a href="https://sites.google.com/site/diygeigercounter/" target="_blank">DIYGeigerCounter</a> <img src="../scipics/_ext.png" />
<a href="http://www.goldmine-elec-products.com/products.asp?dept=1468" target="_blank">Electronic Goldmine</a> <img src="../scipics/_ext.png" />
<a href="http://excelphysics.com/collections/apoc-detector" target="_blank">ExcelPhysics APOC Detector</a> <img src="../scipics/_ext.png" />
<a href="http://www.imagesco.com/geiger/geiger-counter-kits.html" target="_blank">Images Scientific Instruments</a> <img src="../scipics/_ext.png" />
<a href="http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&categoryName=cat_7 0&subCategoryName=Education%20%26%20Hobby%20Kits%20%2F%20Educational%20Kits&category=7030&refine=1&position=1&history=c243uwxf%7Cf reeText~geiger%5Esearch_type~jamecoall%5EprodPage~15%5Epage~SEARCH%252BNAV" target="_blank">Jameco Electronics</a> <img src="../scipics/_ext.png" />
<a href="http://www.madscientisthut.com/Shopping/agora.cgi?product=Radiation%20Detection" target="_blank">Mad Scientist Hut</a> <img src="../scipics/_ext.png" />
<a href="http://mightyohm.com/blog/products/geiger-counter/" target="_blank">MightyOhm.com Geiger Counter</a> <img src="../scipics/_ext.png" />
<a href="http://radiohobbystore.com/diy-kits.html" target="_blank">RH Electronics</a> <img src="../scipics/_ext.png" />
<a href="https://www.sparkfun.com/products/11345" target="_blank">SparkFun Electronics</a> <img src="../scipics/_ext.png" />

[Edited on 20.1.14 by bfesser]

neptunium - 10-1-2014 at 08:24

you know you can build your own scintillation detector ...
thats what i did with a cheap photomultiplier, a 14 pin base from an old oscilloscope a few resistor, there is some plastic scintillator for 30 dollars availlable too. and a high voltage DC power... of course i understand the DC power arent cheap but sometimes with a little luck you can find one less than a hundred bucks on ebay.
i have noticed an increadible increase in the price of radiation detector scintillation crystals and such since the Fukushima disaster...
supply and demand..

[Edited on 10-1-2014 by neptunium]

Varmint - 10-1-2014 at 09:25

For anyone interested in copying the (7) BPW-34 design, if it were me I'd run one op-amp per diode, then sum them all together for the final output.

Reasoning: Being "large area" devices, they have a significant amount of capacitance which hinders their response in both time and amplitude. When you parallel 7 of them, each "strike" which of course only happens on one device, has the combined capacitance of 7 devices to attenuate and stretch the pulse.

DAS

neptunium - 10-1-2014 at 11:03

its a good idea but the thickness is lacking to absorb (and create a signal ) so your spectrum (the photo peak) would suffer greatly making it a wide one smudge...
it doesnt matter for a simple detection but if you want to do spectroscopy its a bust

[Edited on 10-1-2014 by neptunium]

IrC - 10-1-2014 at 16:00

Quote: Originally posted by Varmint

For anyone interested in copying the (7) BPW-34 design, if it were me I'd run one op-amp per diode, then sum them all together for the final output.

Reasoning: Being "large area" devices, they have a significant amount of capacitance which hinders their response in both time and amplitude. When you parallel 7 of them, each "strike" which of course only happens on one device, has the combined capacitance of 7 devices to attenuate and stretch the pulse.

DAS

http://circuitsalad.com/2012/11/19/a-solid-state-photodiode-...

I posted this on page 2 but not a bad idea to look at it again since it discusses this capacitance problem and gives useful math for design consideration. While expensive I think the single large area detector (PS100-7-CER-PIN) is a better route.

http://einstlab.web.fc2.com/Gamma/spectroscopy.html

This link on Gamma spectroscopy is also interesting reading.

The sites main page is Japanese but several English pages are on it which are also interesting such as:

http://einstlab.web.fc2.com/geigerE/geiger.html

He does not provide the code for the Pic, I assume because he sold it to a company to manufacture and sell as a kit. In any case a great project with a wealth of circuit ideas and plans to easily build the 'air Geiger tube'. I especially liked the butane lighter supply of quenching gas since dealing with pump systems and halogens to refill Geiger tubes is not my first choice in a home setting. You really should study this one.

http://j-kosaku.jp/ if anyone is interested in the kit itself.

http://einstlab.web.fc2.com/Xdetector/detector.html

Back to the photodiode subject, this page has a few broken image links but still good reading, image below is from the page. I like this circuit because the LMC662 is not a bad opamp for this circuit but mainly because I have the IC already. Always helps to have everything in stock when tinkering.

[Edited on 1-11-2014 by IrC]

bfesser - 11-1-2014 at 05:41

The follow-up blog post <a href="http://circuitsalad.com/2013/01/08/solid-state-radiation-detector-with-lcd-complete/" target="_blank">Solid State Radiation Detector with LCD Complete!</a> <img src="../scipics/_ext.png" /> (Circuit Salad)

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<hr width="80%" />
Last night, I added a few new <a href="http://en.wikipedia.org/wiki/Rare_earth_mineral" target="_blank">rare earth mineral</a> <img src="../scipics/_wiki.png" /> specimens to my collection. Nothing too fancy, but they exhibit the expected radioactivity. I recieved a small specimen of <a href="http://en.wikipedia.org/wiki/Gadolinite-(Y)" target="_blank">gadolinite-(Y)</a> <img src="../scipics/_wiki.png" /> (also known as ytterbite), a specimen of <a href="http://en.wikipedia.org/wiki/Xenotime" target="_blank">xenotime</a> <img src="../scipics/_wiki.png" /> in fluorite, a specimen of xenotime in quartz, and a specimen of <a href="http://en.wikipedia.org/wiki/Samarskite-(Y)" target="_blank">samarskite-(Yb)</a> <img src="../scipics/_wiki.png" />; all from the <a href="http://www.mindat.org/loc-66693.html" target="_blank">South Platte Pegmatite District, Jefferson Co., Colorado</a> <img src="../scipics/_ext.png" />. A rough measure of the samarskite showed ~3.5×103 CPM, so I put it in a lead pig to keep the cat from sleeping on it. I'm very pleased with these new additions to my collection, but I'm still hoping to get a specimen of gadolinite from <a href="http://www.mindat.org/loc-3191.html" target="_blank">its type locality</a> <img src="../scipics/_ext.png" /> sometime in the future—which may prove difficult, as collecting from the quarry site has been prohibited since the 1970's.

[edit] I've taken and uploaded <a href="http://www.flickr.com/photos/35937732@N02/sets/72157639665100206/" target="_blank">some photos</a> <img src="../scipics/_ext.png" /> of my collection radioactivity related items, including my new mineral specimens. I've also uploaded two short videos to YouTube; one <a href="http://youtu.be/7QmuvC0-F2M" target="_blank">demonstrating the modified firmware</a> <img src="../scipics/_yt.png" /> on my MightyOhm.com kit along with the activity of my samarskite-(Yb), and the other showing the activity of my previously-mentioned <a href="http://youtu.be/HGQlYvI5oWY" target="_blank">'hot plate'</a> <img src="../scipics/_yt.png" /> (~9.5×103 CPM).

I apologize for the quality of the photos, in particular—these are the best I could coax out of my Nikon S9300 point-and-shoot. To exacerbate things, I hadn't noticed that I had left the exposure set low from previous use, which I've tried to correct in GIMP.

[Edited on 20.1.14 by bfesser]

Varmint - 14-1-2014 at 04:46

IRC, why worry about the slight supply mismatch? The CMRR of any op-amps you use will render minimal differences like yours irrelevant.

Believe me, I understand perfection is always a worthy goal, I'm a bit retentive in that way as well. But at some point you have to consider the devices we use (and even discrete circuits we design) can handle these differences without worry.

If low noise is what you desire, a good battery supply with adequate local bypassing can run rings around almost anything mains-connected.

Add a couple of regulators to keep the rails "perfect", and now you've added noise you didn't have before. Let the CMRR do the work for you.

DAS

bfesser - 14-1-2014 at 07:16

I think it was definitely worth the work. Half the fun is the process, isn't it—or is that half the torture? Anyway, this is a bit over my head; I had to look up <a href="http://en.wikipedia.org/wiki/Common-mode_rejection_ratio" target="_blank">common-mode rejection ratio</a> <img src="../scipics/_wiki.png" /> (CMRR). Looking at the specs listed, both op-amps are given CMRR - min: 70 dB. You could try using a <a href="http://www.mouser.com/ProductDetail/Texas-Instruments/TLC2272CP/?qs=sGAEpiMZZMtCHixnSjNA6NDQA1eMYwPy1dlIO6ln6a4%3d" target="_blank">TLC2272</a> <img src="../scipics/_ext.png" /> instead, but from my (limited) understanding, it would restrict your output voltages to a narrower range than the <a href="http://www.mouser.com/ProductDetail/Texas-Instruments/LM1458N-NOPB/?qs=sGAEpiMZZMtOXy69nW9rM4ua1u5LNaSPM2gVRMNTLCs%3d" target="_blank">LM1458</a> <img src="../scipics/_ext.png" />. If you still have the address, could you post a link to the circuit you based yours on?

I finally ordered some BPW34s last night, and am eager for them to arrive so I can start experimenting! In the mean time, I've been brushing up on Civil Defense gear at the <a href="http://www.orau.org/ptp/museumdirectory.htm" target="_blank">ORAU museum site</a> <img src="../scipics/_ext.png" />, and kicking myself for not buying a <a href="http://www.orau.org/ptp/collection/civildefense/cdv750mod6new.htm" target="_blank">CD V-750 Model 6</a> <img src="../scipics/_ext.png" /> when I had the chance.

IrC - 18-1-2014 at 02:23

Spent hours searching neutron production in an effort to find a simple low cost way to produce neutrons to test out my neutron detector. If anyone is working along these lines the partial list of patents below contains much useful information.

Neutron search:
http://www.freepatentsonline.com/result.html?sort=relevance&...

United States Patents for producing neutrons:
------------------------------------------------------------------
2240914 Device for converting atoms
2489436 Method and apparatus for producing neutrons
2211668 Electronic device
2983834 Neutron discharge tube
2251190 Method of producing neutrons
2161985 Process of producing radio-active elements
2500223 Artificial atomic disintegration
0917191 No Title
2206634 Process for the production of radioactive substances
3766389 TARGET FOR PRODUCING NEUTRONS
3167655 Target for a neutron generator consisting of a coating of one of the lanthanon elements on a base metal
2967245 Neutron source for well logging apparatus
3183356 Neutron source
3084256 Neutron generator
2986441 Neutron generator targets
2975113 Method of fabrication of an irradiation transmutation capsule
2859095 Process of producing cm244 and cm245
2816242 Neutron sources
2712081 N/A
2592115 Neutron source
2440999 Compressed neutron source
2253035 Apparatus for the production of a ray of slow neutrons
1620081 Alloy of lithium and aluminum
1333965 Alloy
3320422 Solid tritium and deuterium targets for neutron generator
3124711 No Title
2951945 Renewable target
2576600 Device for generating neutrons
2943239 Method and apparatus for renewing targets

[Edited on 1-18-2014 by IrC]

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IrC - 18-1-2014 at 15:51

Too many patents for one post. Thought I would save people the time looking for the files.

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I should add the search in the post above includes patents for detection while I tried to focus mainly on production in the ones listed here and in the post above.

[Edited on 1-19-2014 by IrC]

bfesser - 7-2-2014 at 06:02

Some links:
<a href="http://dmytry.com/electronics/microgeiger.html" target="_blank">MicroGeiger</a> <img src="../scipics/_ext.png" /> (dmytry.com)
<a href="http://boginjr.com/electronics/lv/no-semiconductor-geiger/" target="_blank">Semiconductor free Geiger Counter</a> <img src="../scipics/_ext.png" /> (Bogin, Jr.)
<a href="http://makezine.com/projects/make-34/hand-crank-geiger-counter/" target="_blank">Hand-Crank Geiger Counter</a> <img src="../scipics/_ext.png" /> (makezine.com)
<a href="http://danyk.cz/gm.html" target="_blank">GM Počítadlo - měřič radioaktivity</a> <img src="../scipics/_ext.png" /> (danyk.cz)
<a href="http://www.mikrocontroller.net/topic/anschluss-und-verwendung-von-geiger-mueller-sbm-20" target="_blank">Anschluss und Verwendung von Geiger Müller SBM-20</a> <img src="../scipics/_ext.png" /> (mikrocontroller.net)

<a href="http://www.atomicrocks.com/html/redbluff.html" target="_blank">Red Bluff Mine</a> <img src="../scipics/_ext.png" /> (Atomic Rocks)
<a href="http://intercontinentalcry.org/a-birds-eye-view-of-uranium-mining-near-the-grand-canyon/" target="_blank">A Bird's Eye View of Uranium Mining Near the Grand Canyon</a> <img src="../scipics/_ext.png" /> (IC Magazine)
<a href="http://rockhounders1.com/Hack%20Mine.htm" target="_blank">Uranium mines</a> <img src="../scipics/_ext.png" /> (John & Shirley Bloomfield )
<a href="http://www.mindat.org/loc-37364.html" target="_blank">Hack Canyon Mine …, Hack Canyon, Hack Canyon District, Mohave Co., Arizona, USA</a> <img src="../scipics/_ext.png" /> (MinDat.org)

[Edited on 7.2.14 by bfesser]

IrC - 7-2-2014 at 11:16

Something about that Hacks Canyon link is confusing. The copper mine was about 11 miles southwest of the location I described, but in 1975 it looked abandoned to me. Did they open it again, as one pic I saw made it sound as if in 1989 they were running the mine again. Am I reading that right? Makes sense I imagine by 1989 copper was starting to rise in price making old mines worth operating again. Hacks Canyon is a cool place, think Martian canals. Miles long with branching tributaries, cut into the earth. Standing on the desert floor you wouldn't think it existed until you walk close enough to see the cut in the earth. What I wouldn't give to go back and explore all that again now that I know so much more about how to look and what to look for. After looking at prices on ebay lately for radioactive rock specimens one could make a decent living collecting rocks in the area. The canyon is miles long with forks and branches all over.

bfesser - 7-2-2014 at 12:39

Yes, I think you are reading that right—I noted the date on the picture, as well. I've never been out in a desert before, only driven through one when I was very little, but from what I saw in photos, the views must be absolutely breathtaking. It looks like paradise to me, with plentiful rocks and geologic formations to study. I would love to explore the entire region; and I bet I'll have dreams tonight of purchasing a claim and prospecting mineral specimens for a living. [sigh]

A quick survey of Google search results hints that uranium mining in the Grand Canyon area has fallen under public scrutiny and has become a political struggle between ecological organizations allied with the indigenous Native American tribes and those who wish to mine the rich deposits. Unfortunately, it also looks like the mineral rights in much of the area of interest have been claimed.

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<a href="http://intercontinentalcry.org/wp-content/uploads/grand-canyon-mining-claims1.jpg" target="_blank"><img src="http://intercontinentalcry.org/wp-content/uploads/grand-canyon-mining-claims1.jpg" width="250" /></a>

<a href="http://www.nytimes.com/2011/03/08/opinion/08tue4.html" target="_blank">The Grand Canyon Uranium Rush</a> <img src="../scipics/_ext.png" /> (New York Times)
<a href="http://www.bbc.co.uk/news/world-us-canada-11350744" target="_blank">'Uranium rush' prompts Grand Canyon fears</a> <img src="../scipics/_ext.png" /> (BBC)

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[Edited on 7.2.14 by bfesser]

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