Nai(Tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator, US $62.50 – Picture 0

Nai(Tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator, US $62.50 – Picture 1

Nai(Tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator, US $62.50 – Picture 2

Nai(Tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator, US $62.50 – Picture 3

Nai(Tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator, US $62.50 – Picture 4

Nai(tl) Large Crystal, 3.5 By 1.2 Inch Scintillation Crystal Scintillator

US $62.50

Poway, California, United States
Jan 30th

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Here is a large, solid optical-grade mass of thallium doped sodium iodide scintillator, commonly known as NaI(Tl). The size is perfect for experimental applications. It is crystal clear without any cracks. The end is covered in an occlusive, peelable material to prevent moisture from getting it. That's why this is never available on eBay for experimental apps like this. A layer of silicone, which can easily be peeled off if you want to couple it with a tube, is covering the exposed portion to prevent moisture adsorption. Sodium iodide is the most popular scintillation material due to the well-known, well-understood physical characteristics and radiation response. It is ideally used with a 1 inch PMT, but experiments don't have too many limits. The long length and width provides highly predictable responses for pulse height analysis, gamma spectrometry, or even single channel analysis. I do sell kits which have a tube pretty much designed to work with these. It very clear, which may not be evident in the pictures. The metal case looks terrible on the outside, but the crystal itself is perfect. Behind the thin metal case, it is held beneath two thin layers; one PVC and one ultra-thin aluminuzed mylar to reflect all scintillations. This forms the surrounding hermetic seal without absorbing low energy photons. I left the metal casing unpainted because these crystals are very consistent and paint would have a small but still present modification of response. NaI is very difficult to work with. It is extremely hygroscopic. It will soak up moisture from the air even if the humidity seems like it's low. It's deliquescent as well, which mean the moisture it sucks up will eat away at it... The first time I worked with it, I had no idea and it ended up as a tan-colored pile of liquid. That was twenty years ago. I re-created this experiment and the last few pictures will show you what I mean. The crystal was left over night in a not particularly humid room. It looked like there were about 10ml water on top, and I turned it over. You can see the results. Keep this stuff away from air. A little coat of silicone after soaking up moisture with a paper towel should preserve it. Then, if you want to use it with different PMTs, make that seal high quality and you're golden. I keep silicone around for everything, so capping these isn't a big deal. It is sealed and contained, ready to rock. Buy it with one of my kits and a few other organic scintillator chunks, you have an awesome setup. No returns on this item unless it is not as described. Removal of the silicon cap means absolutely no returns. Have fun. I rarely have enough of this left to sell. If you are coupling to a tube (it doesn't have to be permanent) make sure to keep the NaI covered with a layer as much as possible, and dry any wetness with a paper towl. Enjoy!