I had to suppress my urge to squeal like a schoolgirl when I saw this video appear in my feed a few minutes ago. Just finished up a few custom scintillation detectors last week, I’ve learned so much from your channel already, can’t wait to hear your take on this!
Wow, you can see the gamma rays slamming in to the CMOS sensor on the camera causing a good amount of pixelating noise.. that's a pretty hot source for sure! thanks Carl for sharing
@@shannonpincombe8485 No problem - starting at about 3:56 when he shows the video from the camera close to the source, you will see a few bright dots in the video at random spots. It could be beta too if it's close enough, but most likely it's because the gammas - they are stripping electrons off of the CMOS sensor substrate within the camera.. that translates in to these flashes of pixels. some videos show them in more abundance -- google CMOS radiation noise - you should see better examples. hope this helps.
What a great image! I love how you can see slight snow on the camera right next to the source, and yet the final picture turned out pretty clean. This really makes me appreciate my scintillation crystals, and the gamma spectrometer they make up. Thank you for the great image and reminder about the nuclear science week!
Haven’t checked your channel in a while… I see you’ve been busy over the last year! I will very much enjoy going through and watching your proportional counter videos and especially your scintillator test bed and videos!!! That’s “dream come true“ RU-vid content for me right there!
I have a Radiacode 101 gamma spectroscopy and scintillation detector. It utilizes a CsI(Tl) crystal with a SiPM. It has lousy resolution but it is a fairly capable spectrometer regardless. I have some great Reference spectra for my library that I have collected. Great video! Lots of great information. Thank you Carl for your work.
This was really cool to see! I think in the last year I read "LYSO" hundreds of times and I knew its peak emission wavelength, but actually seeing what it looks like (or would look like in a very unhealthy environment) is a completely different thing!
I love your work, Carl! I saw that LYSO scintillator, and I knew exactly what it was! It is slightly radioactive (Lu-176), and is a nice low-moderate gamma energy calibration source (88 keV, 202 keV, 307 keV), with high branching intensities. I use NaI:Tl and PRA, with a GammaSpectacular MCA. It works well! CeBr or SrI:Eu have about twice as better resolution, but they're expensive! HPGe is the best, and I'd love to get my hands on one, but they're crazy expensive! Anyways, thank you for sharing your amazing work! Thank you so much!
Carl, I love your videos. You really have a great narration voice and you are an excellent educator. Thank you for all of your efforts. And gosh darn it, be careful!
We may only get 2 videos a year from Carl, but when we do.... it's a good day! Bionerd has an amazing video from years back showing various scintillators glowing too (in video!!) under a radiation therapy linac.
Andrew Seltzman has some good ones of cameras and scintillators going through an electron beam system. I think it was an industrial system for cross-linking polymers. You get some nice views of the purple ionized air, flashes from x-rays, the scintillators glowing like light bulbs, and then the cameras going to snow from all the radiation even though they are heavily shielded.
@@trustthewater indeed. they were amazing and I was subscribed until a year or so ago when he decided to go completely insane and totally shitted up his whole channel with about a thousand leftist protest videos. ain't nobody got time fo dat. has he decided to come back to reality since?
@@bltc11 sometimes people just need to dip out. Best guess from me would be that she finally said fuck it after the millionth "zomg ru dead of teh cansur yet??" comment.
💕 Carl, Your the Only guy in town, that has a ton of giant Lead Blocks, kicking around your house and office! Says a lot about how good you are in this field. 😃
Awesome video! I do a lot of testing with scintillators for a company that makes compact high resolution RIIDs and PRDs with CsI:Tl (7% resolution) and CLLBC (sub 4% resolution) scintillators. Love your videos, very informative.
@@Carl_WillisYeah it's incredible stuff. The neutron discrimination ability is phenomenal. If only it wasn't super hygroscopic, it can be a bit of a pain to work with.
I love your video and the scintillator photo. Your explanation of the materials was excellent and I bet your students really get a kick out of your classes since you have a great way of expalining rhe practicle uses for each of the scintillators you used. I wish we could catch the 'flash moment' you referred to for each of the materials and tell their reaction times. Great footage and thank you.
This was excellent. Thank you for this video. I once interviewed for a job at UCLA working on a project looking for dark matter using fiber optic scintillators. They're looking for WIMPS as a dark matter possibly. I didn't get the job, but I think it would have been a lot of fun.
Very interesting video! I am slightly disappointed however that Lanthanum Bromide was not shown. Lanthanum bromide offers excellent energy resolution properties which is very beneficial for high-end gamma spectroscopy applications.
Lanthanum bromide (and many other high-performance materials) are not shown because they're expensive and I don't own a sample. It seems I need to periodically remind people that my videos are self-funded. Every scintillator shown here is personally owned and was acquired incidental to some personal project. I welcome donations and opportunities to review different capabilities that I don't presently have.
Thank you for making this content, it's really fascinating to me, radiation and the scintillating materials too. Some interesting rarely used elements and chemistry too!
Wow, nice you have access to such a strong source! The possibilities for experiments are endless. How thick are the walls on the shielding container, and what material is it made of?
Was this video also a way to tell the university to give them better equipment to handle the radioactive stuff?, Anyway, amazing video and very informative!
Actually, the lab already has a couple long remote handling tools. I prefer the $2.50 Costco option because it's exactly the right size for the job at hand.
Nice to see the actual light from gamma interactions. I just us UV to check scintillators and wondered if the same light wavelengths are emitted. I guess some of these scintillators may not react to UV light.
Yep, UV light works well with most of these materials (though it will photochemically blacken Hg2Br2). Just not as fun as putting them on an actual radioactive source!
If you want, i can place some of these into a 80KeV Electron beam as well. Or if you wait until mid next year, a 400KeV electron beam. Dont have many scintilators seen in the video on hand though, as i mostly use other ones.
Hey this is much easier than using one of those little dinky Am241 sources from a smoke detector! That actually did work with a GSO and produced a very faint spot of light right near the source after one hour of complete darkness and 10 years worth of eye strain to see it. While less exciting a mineral display case with UVC lights works as most fluoresce in some fashion. NaI and YAP were the two nicest looking, esp. YAP with its vivid deep purple glow.
Hey Carl, I see that there’s a leaded glove box behind you in the intro, what sort of experiments do you guys perform in there? Also Go Lobos, Class of ‘19
Hi, has there been research done on photoelectric energy conversion and scintillators? Like, can you take the light from the scintillator and convert it to electricity? Or has it been considered to dangerous to experiment?
Heh I took some tape with zinc sulfide film on it and made about a 1 square foot phosphorescent screen on my wall. I hit it with a UV flashlight and it makes for a nice nightlight that turns itself off after about half an hour. Or, I had fun getting it to glow with a small van de graff generator. I could actually visualize the electric field lines! I doubt an alpha particle could get through the plastic lamination on it, but I'd love to hit it with a beta source, if I could get one, or stick it in a home made cathode ray tube as the target. Maybe put an iron cross in front, for nostalgia's sake.
Great video! How many visible photons does one gamma ray photon produce in a scintillator? Does the gamma photon travel in a straight line kicking off visible photons in it's path, each time slightly reducing it's energy?
The number of visible photons is a function of the material, the energy of the gamma ray, and the type of interaction that the gamma ray experiences. Obviously, it's higher in the brighter materials. It also typically scales linearly with energy for photoelectric absorption. The photon can interact by being absorbed or being scattered, and typical scattering events change the direction and energy of the radiation substantially (e.g. via the Compton effect).
If I may answer for him - no, the scintillators would not contain any radioactive material because this would defeat the point. They are used for radiation detection and including radioactive material would cause an increase in noise, which is undesirable. Granted, the lutetium dopant of one of them is very slightly radioactive because one of the naturally-occurring isotopes of lutetium (Lu-176) is slightly radioactive. But since it is a doping agent, it is only added in small quantities, presumably too small to affect the signal-to-noise ratio much. One thing to notice is that two of the most common scintillator materials are Tl-doped NaI and CsI. It would also be possible in principle to use KI or RbI, but those aren't used because K and Rb are both naturally radioactive.
That is really interesting. Two questions: how long was the exposure time to get this picture? And also: if you would stand there in the dark, would you be able to see those flashes with the naked eye?
Is the CsI crystal so bright because its atoms are so heavy hence the high density and higher chance of interaction? I just wonder whether the combination of heaviest (stable) alkali metal with the heaviest (stable) halide has something to do with it...
Great channel! My father in law did a lot of research on kosmos 954, even took a lone expedition up there to search for it. He has some information about it that was not mentioned in your vice video. He would love to talk to you and or Taylor about it. He’s a Reno local. He has a RU-vid channel called David Jenner. He’s put some kosmos videos on there. That’s not his name. This is the only way that I found to contact you. I hope you see this comment. I’ll put you in touch if you’re interested.
Hello and thanks for mentioning your father-in-law's interest in the KOSMOS-954 satellite. I'd welcome making contact. We had a good time making the VICE show and met a lot of people directly involved with Operation Morning Light. Very little technical background made it into the final cut of the tv show, but Taylor and I geeked out hard on these details extensively. My email address is on the channel homepage and I can also be tracked down at my University of New Mexico job. Thanks and best regards!
I've always wondered if in the future we would have the technology to create radiation cameras, that would detect the direction of radiation. Similar to infrared heatmap cameras but for beta radiation for example.
they exist but it's much harder and more expensive to do with gamma rays. with x-rays you can at least use grazing incidence low angle reflection off of parabolic / hyperbolic nested mirrors, but you can't even do that with gamma rays and the only options left are pinhole cameras (ridiculous low efficiency and useless for all but the most insanely active sources) and zone plate coding apertures (heavy, still poor efficiency, awful spatial resolution)
Some technology now enables a direction vector to be obtained. Gamma rays are indirectly ionizing, but it's still possible to reconstruct the initial direction using the properties of Compton scattering.
Is the yvo4 crystal regular or neodymium doped? Used them for making lasers many years back. Also used to build awsome little neutron/soft gamma detectors for ludlum 2's and 3's from bad surplus scionix LiL:Eu detectors and Adit photomultiplier tubes salvaged from hurricaine flood damaged VACIS wands. The scionix detectors were originally for SAIC identifinders but the little metal can hamamatsu PMT couldnt take the soldering and would slowly leak. The Vacis wands were from gamma cameras used to inspect ocean containers. They had rather large NaI:Tl crystals, all water damaged, but usually salvagable if determined. Cut the scionix detector in two with a pipe cutter and optical epoxied to the adit tube in a nitrogen purged glove box- Li iodide is stupidly hygroscopic 😲. Put the works in a stainless travel cofee mug with a removable moderator molded in the cap and bnc or c-hv connector on the back. Was very specific for neutrons when running the pmt at about 700v or so, at just under 850v it would let you know where a smoke detector was through the wall from the gamma scatter! Those were good times 🤓
Thanks for the info. To add my 2 cents... Just came along of cheap CsI:Th based spectrometer/dosimeter, while the crystal is about 1 cubic centimeter large. Its in sealed package, as i understand it might behave similarly to a table salt - attract water in moist environment. I assume that CsI:Th spectrometer/dosimeter would not be the most accurate, but since it produce the highest amount of light it will be quite sensitive, and here is the thing why i even consider to buy such spectrometer... a) I live in Central Europe, and there might be residuals of Cs-137 in nature (mainly mushrooms) and I would like to see for myself if the contamination is real. b) There is a really bad trend of using Thorium Oxide in "energetic pendants", and I would like to demonstrate to people that the products they sell are radioactive, and which radionuclide it is.
Sure enough. It's not mentioned, but the image shown here is a stacked composite of three exposures. It's still unacceptably noisy, but the only good solution would be a thick lead glass window that weighs 100kg and creates its own problems.
@@Carl_Willis The image is still perfectly fine for its purpose anyway. Even though the background noise is readily visible on closer inspection (at least on 1080p, less so on 720p), it is really not distracting and in fact I probably would not even have noticed it if you hadn't pointed it out in the video, so I'd call it acceptably noisy! (Of course I can only call it acceptable because I'm not the one who made the image, if I were I'd undoubtedly have spent waaay more time than it's worth to try to get rid of it ;-)
Wow, small world! Two of the smartest people I have ever come across. One a Beagle Bone/Linux wizard, and one a radiation wizard :) Great respect to you both!
This is a reasonable approach if you have a long lens with a fast aperture and are willing to invest a lot of time and effort stacking lead. It's an approach I have situationally adopted. But it wasn't viable when I was making this video.
Scintillation detector packages in surplus have some residual value, as people sell them all the time on eBay. The crystals themselves may or may not have any value...depends on material and condition.
Hi Carl do you know if bionerd23 is safe and ok? I have been trying to figure this out for like 4 years now. Every so often checking to see if she uploads again. I contacted one of her bike friends and he told me she was missing. I just never thought of looking at her related channels until today
