According to a few sources [1-2] radon is radioluminescent and glows yellow to red, depending on temperature, when cooled to a solid state.
Anybody know if this has ever been photographed in color? Or in general, are there any photos of bulk radon in either liquid or solid form?
[1] https://education.jlab.org/itselemental/ele086.html
[2] https://www.britannica.com/science/radon
I can't say I'm surprised, even a few hundred milligrams of Rn-222 would still be like a PBq of activity. Rather hot. And it's not like this is something you can just buy off the shelf from Sigma and ship to your lab.
@gigabecquerel any ideas on sources I might have missed? So far haven't found a primary source, just encyclopedia web pages etc claiming it's radioluminescent without any photos or spectra.
@azonenberg I'll be honest, this is the first time I'm hearing of this.
Sounds like something that would have been discovered / researched in the 30s, so good luck finding any original sources
@gigabecquerel @azonenberg I mean at that activity and a decay energy of 5.5 MeV as for Rn222's α-decay, that'd be 0.9 MW/g of fission power; kinda makes it hard to keep a sample at solid state.
if I'd be to speculate, the orange-to-red glow is alpha particles exciting electrons within glass and glass-embedded He from previous α bombardement, maybe Cherenkov ultraviolet causing reddish fluorescence.
@funkylab @azonenberg Radon doesn't fission, and your decay heat is off by a few orders of magnitude. Rn-222 has a specific activity of 5.96 PBq/g, multiply that by its decay energy of 5.6 MeV and you get just about 5 kW/g.
At a melting point of around -70 °C that's definitely in the range of "Doable" with eg. a lot of dry ice and a very small amount of radon.
@gigabecquerel @azonenberg ah if the activity estimate was off that much, yep, OK. (Sorry about the fission, that was a brain blep.)
@funkylab @azonenberg Maybe you were mixing up Rn220 and 222? Rn-220 has a decay heat of 35 MW/g, that's a lot closer to your guesstimate.
@gigabecquerel @funkylab Anyway, I guess the short answer is "I'm unlikely to ever see a photo of it because the only person crazy enough to accumulate and freeze that much radon did so more than a century ago and it's probably never going to be repeated"
@azonenberg @funkylab Be the change you want to see in the world
@gigabecquerel @funkylab Lol. There are things I'm willing to do in the name of science but accumulating enormous quantities of radon is not one of them :P
@azonenberg @gigabecquerel at least you wouldn't have to deal with it for long
@funkylab @azonenberg @gigabecquerel "Well, that was nice. Let's stop the cooling and do something else."
@gigabecquerel @azonenberg 1890s I think. Before Rutherford did his alpha particle/gold foil work at McGill. Which I think was 1908s ish.
@mcr314 @gigabecquerel Ok, so yeah, very likely no photographs were ever taken (or at least, none survived to the present day).
@mcr314 @gigabecquerel following up: LNHB has a primary standard [1] that can produce solid Rn-222 samples with precisely controlled activity ranging from 100 Bq to 3 MBq depending on how long you accumulate for.
3 MBq is roughly 1 ug if my mental math is right. I wonder if that's large enough to produce visible radioluminescence?
[1] http://www.lnhb.fr/home/presentation-en/radon-measurement-facility/
@azonenberg well. Usually they go to the lab and do stuff with each element....