Sciencemadness Discussion Board

Luminescent material for X-ray project

Melmoth - 23-8-2013 at 10:26

I'm looking for a chemical which lights up when exposed to X-ray. I was thinking something like ZnS, would this do the job?

watson.fawkes - 23-8-2013 at 11:51

What search terms did you use to look for such information before posting? And what search engines did you use?

[Hint: "phosphor"]

Melmoth - 24-8-2013 at 00:22

I know phosphors are used in all kinds of x-ray screens, but thats not what i'm looking for. I thought I could post it here, but somehow youre constructive reply tells me otherwise..

watson.fawkes - 24-8-2013 at 05:38

Quote: Originally posted by Melmoth  
I know phosphors are used in all kinds of x-ray screens, but thats not what i'm looking for.
If it glows when hit with x-rays, it's called a phosphor, whether or not it's used in a screen.

IrC - 24-8-2013 at 10:15

Quote: Originally posted by Melmoth  
I'm looking for a chemical which lights up when exposed to X-ray. I was thinking something like ZnS, would this do the job?


Must be made with Ag activation for your purpose, otherwise you will barely see response to even gamma. Have you searched for screens used in fluoroscopy? Materials such as barium platinocyanide or the better while chemically safer calcium tungstate? Edison figured this out long ago. From the page:

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

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

"I'm looking for a chemical which lights up when exposed to X-ray."

"I know phosphors are used in all kinds of x-ray screens, but thats not what i'm looking for."

This is confusing to me as well as Watson. Your first post said you were looking for substances which glow in X-rays. Then you say it's not what you seek. Few of us know any materials which scream "owie the pain" when hit with X-rays. We mostly settle for materials which quietly glow and are happy.

I do believe however new members with few posts should not be given the USTFSE treatment (no one here has thus far), they should be guided towards proper etiquette (which I thought Watson did quite well and politely). In this way they learn to not put the jobs they easily could be doing upon others.

"I thought I could post it here, but somehow youre constructive reply tells me otherwise."

Comments such as the above from new low post count members who were politely steered in the right direction concerning not only the subject at hand but also proper conduct are a very bad beginning. Watson was helpful and most polite and your response to it was not.

Not desiring to badger you, new member, but get real. Your over-reaction to Watson is not such a great start. He was giving you polite useful information which was the answer you were seeking. If it was not what you were looking for perhaps you should post the question in a more useful way?

http://www.ebay.com/itm/ZnS-Ag-scintillation-screen-spinthar...

I have bought these from this ebay seller. However it takes time getting your eyes used to darkness to even barely see flashes from gamma so unlikely your ZnS/Ag idea is going to be of much use for X-rays.


[Edited on 8-24-2013 by IrC]

Melmoth - 24-8-2013 at 11:02

I'm sorry if I offended you, I'm not a new member as you can see, but rarely post.. Unless I realy need to know something. I did find the answer from watson not very constructive, and it might be a translation problem in this case, but I found it offensive aswell..
As for the screens i work with, they don't light up visibly when in contact with x-ray so that might explain my question/reply. I iknow i'm might not be on the same level as you guys but that's what I'm here for right.
Thanks for the info IrC I will seek further..

IrC - 24-8-2013 at 11:54

You know, I didn't even look at the date just the count. I do not think He was trying to be offensive but I cannot speak for him. Just sounded like He was asking if you searched and what terms were used. I spend much time experimenting with materials along this line and honestly the best ones are well known/used in the art. You mentioned ZnS and even with Silver activation the material is not all that great even for Gamma, worse for X-rays. If getting light from a material irradiated with low energy photons in the X-ray spectrum is the goal I believe Watson's idea is good. Search for materials used in medical screens. My reasoning for this is I assume over decades to protect patients from burn much work has been done getting better light output from the lowest possible energy. At least it sounds like a reasonable assumption to me.

Edit to add I don't think anyone has been offended in any way, chalk it up to google translate?

Also to add: I have had fair results using Ca and Sr Aluminates I have created in a reducing atmosphere for what it's worth. In these I have experimented with doping using various Lanthanides, Eu and Dy being good choices.

An interesting patent US1563856A, mentions ZnS with Cu activation. May be worth looking at.

Attachment: US1563856A.pdf (223kB)
This file has been downloaded 441 times


[Edited on 8-24-2013 by IrC]

Melmoth - 24-8-2013 at 12:27

Ok let's drop this non-topic issue.. Apologies on my side.

Nowadays I work with lead foil screens from NDT, they are to be scanned and show no visible illumination. Before I used the Polaroid system to make radiographs.

Did you have any experience with platinocyanide, like Barium platinocyanide, Ba[Pt(CN)4]?

(Nice upload btw, brings ZnS back in the picture..)

[Edited on 24-8-2013 by Melmoth]

[Edited on 24-8-2013 by Melmoth]

unionised - 24-8-2013 at 12:46

This might also help
http://en.wikipedia.org/wiki/Scintillator

IrC - 24-8-2013 at 13:35

Quote: Originally posted by Melmoth  
Did you have any experience with platinocyanide, like Barium platinocyanide, Ba[Pt(CN)4]?


No I avoid toxic chemicals if possible, I got that reference from the wiki page. Mostly I toy with ceramic materials, aluminates and the like as ultra persistence glow powders is where most of my chemistry experiments occur. However I have tried about every version of ZnS /activation elements I have read and/or dreamed up. Such a poor choice in my experience. Rare earth doped materials are so much better. Likely true for what you are desiring as well. Below are patents of interest. Assuming I can get multiple patents to show up. I keep getting called away and interrupted in the middle of edits and delete files when trying to add multiple files. Don't ask, I keep coming back and hitting browse file instead of add another.

Attachment: US3225193A.pdf (467kB)
This file has been downloaded 459 times

Attachment: US3563909.pdf (204kB)
This file has been downloaded 456 times

Attachment: US3829700.pdf (275kB)
This file has been downloaded 443 times

Attachment: US4256965.pdf (95kB)
This file has been downloaded 442 times


watson.fawkes - 24-8-2013 at 15:24

Quote: Originally posted by Melmoth  
Ok let's drop this non-topic issue.
Let not, since it's part of the actual topic, which includes both your actual question and whatever is in your mind that you think you're asking.

Four posts in this thread now, and you still have provided almost zero information about what you're actually trying to do. This isn't a case of translation, this is a case of you asking a question that is not well-formed enough to make it possible to provide a helpful answer. The reason I asked if you'd searched on the internet before asking your question is because it seemed that you had not. I am more convinced now than before that you've done no prior research on this, not even cursory reading. This is indicative of laziness, and I'm not inclined to spend my time spoon feeding the lazy.

Melmoth - 25-8-2013 at 00:50

Quote: Originally posted by IrC  

Rare earth doped materials are so much better. Likely true for what you are desiring as well.


Thanks for the info! Reading from your patents these must be the elements of choice, although they might be a bit hard to get since I'm in Kabul now..

Europium seems widely used and internet available though.

phlogiston - 25-8-2013 at 04:05

Bounty of Rare Earths Discovered in Afghanistan

The phosphors used in CRT TV's, white LED's and fluorescent lighting tubes are often rare-earth based. Could these be used as-is for the OPs purpose?

[Edited on 25-8-2013 by phlogiston]

[Edited on 25-8-2013 by phlogiston]

IrC - 25-8-2013 at 15:28

http://en.wikipedia.org/wiki/Phosphor#Radioluminescence

A page useful in your quest. While focus is on radioactive materials causing a glow it's not a stretch to use this knowledge for your Xray purposes. After all many if not most of these materials will glow from photons in frequency all the way down to Ultraviolet. One would assume then even if not the stated application decent light output can be realized even from fairly low energy Xrays. The phosphors mentioned by phlogiston are also worth experimenting with. Lacking a commercial Xray tube for testing materials, one can try some of these home made ideas for Xray sources.

http://www.dangerouslaboratories.org/xray1.html

http://www.belljar.net/xray.htm

http://www.kronjaeger.com/hv-old/xray/intro/

http://hackaday.com/2012/05/17/making-a-miniature-x-ray-tube...

Hopefully stating be aware of the dangers is not needed. Anyone unaware should not be toying with this area of science to begin with.