Originals still going strong
I still have some of he original Traser glowrings, still glowing away quite brightly. I'd say the ten year estimate on them was conservative to say the least
It's official: El Reg's merchandising tentacle Cash'n'Carrion has regained its atomic keyring capability with the arrival in our virtual emporium of the Nite Glowring. The six flavours of glowring You demanded the return of the legendary tritium-powered Traser, but sadly they'e no longer available. Instead, we've sourced …
Dear Sir,
Please find enclosed a cashiers check drawn on my account at the Central Bank of the Islamic Republic of Iran for £5,990,000. I would like to order one million (1,000,000) of your delightful (and legally exportable) Traser mini-key rings. They will make wonderful gifts for my distant relations to the west.
Please send to:
Mr. Michael Smith esq.
Secret Santa Coordinator
Complex #7, Reactor Assembly Building
Bushehr, Iran
B00M1E
It's more a "might start looking ropey" rather than a "will stop working after" thing; tritium has an half life of a bit over 12 years, so after that long the glowring will only be (at best) half as bright as it was originally. Dropping to a quarter as bright as it started after another 12 years, etc...
(That's assuming the phosphor doesn't degrade, or any other factors creep in to nobble it...)
Remember that your eyes' response to light is pretty much like the ears' response to sound - logarithmic. The bright daylight today is clocking up ~50,000 lux on my light meter whereas a room at night lit by a single light bulb may be about 100 lux or less but your eyes adapt, so a factor of 2 or 4 is no big deal.
"I still have some of he original Traser glowrings, still glowing away quite brightly. I'd say the ten year estimate on them was conservative to say the least"
Half-life. The half-life of tritium is 12 years or so. That means that statistically, roughly, approximately half of the tritties should have gone "ping" and changed into helium every decade or so. Which roughly, sort of implies that the juice should kind of die in about fifty years or so. Ish. About, give or take a while.
It's all very quantum and probabilistic and stuff, involving the weak force,, but these things might visibly glow in the dark for a century or more. They'll just glow less and less brightly as time goes on.
It's entirely possible that the phosphors are set up to be super-saturated at birth, so the first decade or more is just un-flattening the top of the brightness curve and no *noticeable* change in brightness will be seen for a couple of decades. At least, that's how I would design them.
Just remember, if you have one of these things you are carrying around a thermonuclear device, a nuclear reactor and a generator of beta-rays.
Cool, yes?
You are not allowed to ship the larger one world wide but you can ship the smaller one? What if some nefarious overseas individual buys two of the smaller ones? Or even a whole box full?
TRIIITTIIIAAMMMMAGEDDDON !11!!!!11
Oh, my bad. Here I was assuming the export restriction rules might actually be based on common sense...
"...and why can't I have a large green one…?"
Because the Guardians of the Universe forbid it.
However, you need an awful lot of tritium and it is a little hard to handle in these quantities. When we had 500Ci or so on site I did actually calculate what volume it would occupy if converted to tritium oxide, and how hot it would get if I could keep it all together long enough. It would easily fit into one of these lights, until the case either exploded or melted locally.
Because of its short half life and low atomic mass, tritium really is very radioactive. Fortunately it benignly emits low energy electrons and does no harm till you breathe it in or swallow its oxide. If it is bound in a nonvolatile compound it's pretty harmless and the byproduct is helium 3, which is innocuous. Fortunately because the preferred route to disposal for the British government has been from Windscale sorry Sellafield straight into the Irish Sea, and the last I heard it was well into the gigaCi.
Ah, yes, the "Castle Bravo" effect:
http://en.wikipedia.org/wiki/Castle_Bravo
One presumes that they've also tried Lithium Trinitide as well as Lithium Deuteride, although I couldn't find any references while doing a very quick search. ("Hi guys/gals!" I always include a friendly greeting to any spooks who may be reading my stuff, based on selected/sensitive keywords.). Then, again, most aspects of nuclear weapon design are somewhat classified, well, excepting for all of that design information on wikipedia/wikileaks/etc. :-/
Dave
Slip on the appropriate key and apply with 2-sided tape above the keyed switch for the generator/UPS/battery supply so you can find it when the power is cut, especially after it was left in the wrong position after the once-monthly test last done sometime last year.
Actually a glob of silicone cement would be better, make someone work to remove it.
Without the ring, you can use the hole to screw one to the door frame to keep the keyhole illuminated. Lots of fun possibilities.