Trinitite (atomic bomb glass) radioactivity and gamma spectroscopy

[@KarbineKyle]

Awesome video! I finally got a 1" NaI:Tl GammaSpectacular spectrometer kit, and I use the PRA software with it! It works great, even though the efficiency is lower, since I'm using a smaller crystal. I'd love to try CeBr3, from Berkley Nucleonics, but it's so expensive! HPGe would be the best of the best! I was able to identify Kr-85 (514 keV) from some old Western Electric electron tubes, ca. 11/1973, 15 μCi, which both only give me about 500 CPM on my Inspector USB Geiger-Müller counter, now that the activity is only about 0.637 μCi, 49 years later. I'm going to try Pu-239 next (17.1 μCi, total) from old Soviet smoke detectors, to see if I get any of the low-energy gamma energies, like Am-241 and _maybe_ U-237 from Pu-241, which undergoes β- decay, which emits very low-energy-about 20 keV β- particles, and on occasion, α decay to U-237. The problem is that plutonium isotopes have low branching ratios for gamma rays. It's easily detectable up close, with my Inspector USB Geiger-Müller counter, however, a sheet of paper blocks _almost_ all of the radiation, being mostly α particles. Even my CD V-700 on "X1" only goes up to about 100 CPM (β and gamma) per source. I was able to detect some gamma energies from my trinitite, but at a lower efficiency, since your NaI(Tl) crystal is twice the diameter of my detector. Anyways, _excellent_ video on my favorite hobby! I'm glad to see when you post a new video, as they're very well done! You're a smart man, and your methodical approach is paramount! Very well done! Thank you for making this! Have a Merry Christmas and a Happy New Year! 👍

[@AJApper]

Thank you for your nice and detailed message and your compliment. Enjoy this exiting hobby. Happy New Year !

[@AJApper]

@Muonium 9 years ago I made my first video on gammaspectroscopy. kzbin.info/www/bejne/Z2SraH1snJKrp9k At 1:48 you can see the primitive device I mentioned to connect the scintillator to a PC o r laptop soundcard.

[@Muonium1]

Do you believe this would be possible to replicate with a Raysid or possibly even Radiacode 101 spectrometer?

[@AJApper]

Perhaps. The scintillator crystals in these devices are small : Raysid has a 5 cm3 CsI(Tl) crystal and RadiaCode 101 contains a 1 cm3 CsI(Tl) crystal. This means efficiency will be low. I registered the Trinitite gammaspectrum with a Scionix 2" scintillator, around 100 cm3, and it took several hours to get a decent spectrum. Although efficiency is not linear with respect to scintillator size I assume it will take many many hours to get an interpretable spectrum with the devices you mentioned. After all, gamma radiation level of the Trinitite is only slightly above background. Circumstances, especially temperature, should also be perfectly constant during these hours, because otherwise energies will be shifted a bit which deteriorates the spectrum accuracy.

[@Muonium1]

@@AJApper this is what I suspected might be the case. thanks. looking for the cheapest way to start doing spectroscopy, but worried about resolution of the tiny portable devices and the fact that the Raysid is totally sealed and will become a paperweight once the battery inevitably dies in a few years.

[@AJApper]

@Muonium, you could start with a 1 “ NaI(Tl) detector from Ebay. Connect the scintillator to a laptop running PRA software. A few years ago I used a very simple device to connect the scintillator to the computers soundcard. A capacitor to block the scintillator’s high voltage and a 220 kOhm potmeter to adjust the level. Although rather primitive, it is a cheap solution.