[angkor]

pretty short half-lives, and tolerance for some of the daughter products is pretty low in a "fractional crit" device.

What are more accurate descriptions of "pretty short" and "pretty low"?

[Poohbah]

Tritium is a required element in "fractional crit" devices for generating a VERY high neutron flux. (Tritium "boosting" involves injected tritium into the pit as it reaches maximum compression. It's used in both fission and fusion weapons to maximize fission yield.)

Tritium has a half-life of 12.3 years, and decays into Helium-3. Helium-3 has a voracious appetite for neutrons; a very small amount of ³He₂ will "poison" a chain reaction by absorbing neutrons faster than they are generated, and in a "fractional crit" device, said helium poisoning will completely prevent a nuclear yield. (A bunch of tests in the 1950s failed to generate ANY nuclear yield because of this issue.)

[Delta 21]

Its all relative. HA! (I kill me.)

from Garyhope It will be the last thing the Muslims ever do.

You Got That Right.
Delta 21