Groundwater dating and residence time measurements
The same is true, albeit to a lesser extent, of deuterium.This is why brown dwarfs (so-called failed stars) cannot utilize ordinary hydrogen, but they do fuse the small minority of deuterium nuclei.However, if the atoms have a high enough temperature and pressure (for example, in the core of the Sun), then their random motions can overcome such electrical repulsion (called the Coulomb force), and they can come close enough for the strong nuclear force to take effect, fusing them into heavier atoms.
It can be produced by irradiating lithium metal or lithium-bearing ceramic pebbles in a nuclear reactor.
Beta particles from tritium can penetrate only about 6.0 mm of air, and they are incapable of passing through the dead outermost layer of human skin.
The unusually low energy released in the tritium beta decay makes the decay (along with that of rhenium-187) appropriate for absolute neutrino mass measurements in the laboratory (the most recent experiment being KATRIN).
The low energy of tritium's radiation makes it difficult to detect tritium-labeled compounds except by using liquid scintillation counting.
Tritium is produced in nuclear reactors by neutron activation of lithium-6.