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bfesser
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Interests in Radioactivity & Nuclear History
Quote: Originally posted by bfesser  | | 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 <em>I love this thing!</em> The kit is
<em>very</em> 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" />
<em>Oh,</em> 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]
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plante1999
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I am indeed interested!
I had bought that kit, but it never passed trough the customs, what an huge lost of money!
I never asked for this.
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bfesser
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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?
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plante1999
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confiscated. Probably due to "nuclear material" content.
I never asked for this.
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bfesser
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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?
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plante1999
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Nope.
I still want one of those, but I already have spend the cash one time, so yea.
I never asked for this.
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bfesser
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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]
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Fantasma4500
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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
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IrC
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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?
"Science is the belief in the ignorance of the experts" Richard Feynman
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mr.crow
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| 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.
Double, double toil and trouble; Fire burn, and caldron bubble
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bfesser
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<strong>IrC</strong>, 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.
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Wizzard
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I have some family in Canada - I might be able to help if something is stuck up there.
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IrC
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@bfesser "disturbingly hot"
How hot in mr/hr?
"Science is the belief in the ignorance of the experts" Richard Feynman
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Ozone
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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]
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
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bfesser
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Hot plate?
<strong>IrC</strong>, 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.
<strong>A few noteworthy webpages I've come across:</strong>
<strong><a href="http://hps.org/publicinformation/ate/faqs/radiation.html" target="_blank">Radiation Basics</a></strong>
<img src="../scipics/_ext.png" /> (Health Physics Society)
<strong><a href="http://hps.org/publicinformation/ate/cat47.html" target="_blank">Radiation Basics</a></strong> <img
src="../scipics/_ext.png" /> (same site & title, different page... bad web design practice)
<strong><a href="http://modernsurvivalblog.com/nuclear/radiation-geiger-counter-the-radiation-network/" target="_blank">Geiger Counter
Numbers, How Bad is Bad?</a></strong> <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 <em>'surprisingly hot'</em> 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! <strong>IrC</strong>, 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]
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BobD1001
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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.
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Varmint
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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. <sup>40</sup>K is everywhere!
DAS
[Edited on 29-8-2013 by Varmint]
[Edited on 29-8-2013 by Varmint]
[Edited on 29-8-2013 by Varmint]
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IrC
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| Quote: Originally posted by Varmint | | Don't forget to take some readings on Beer, bananas, and nuts of all varieties. <sup>40</sup>K is everywhere! |
But I like bananas
http://www.youtube.com/watch?v=lWcxZe_-Wrs
Is that why my mind is glowing?
"Science is the belief in the ignorance of the experts" Richard Feynman
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dontasker
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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.
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bfesser
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Thanks for sharing the link, <strong>dontasker</strong>. 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">I<sup>2</sup>C</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.
<strong>Varmint</strong>, 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.
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dontasker
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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.
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Plutonium239
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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.
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IrC
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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/
"Science is the belief in the ignorance of the experts" Richard Feynman
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bfesser
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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.
<strong>IrC</strong>, those links are great! Thanks for sharing.
[Edited on 3.9.13 by bfesser]
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Marvin
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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.
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