Front sight on Rem. 870 Scattergun Technoloties Border Patrol shotgun

[mojave30cal]

I bought a used Scattergun Technologies Remington 870 Border Patrol shotgun about 10 years ago. It has the Trijicon front sight with the
white Tritium dot. How long do these illuminate? Mine seems to be kaput. What is the procedure to get it working again?

[Synchronizor]

Tritium sights are so-named because they contain tritium, a radioactive isotope of hydrogen with two neutrons in its nucleus along with the normal proton. It naturally undergoes radioactive decay, converting to helium-3 and releasing beta particles in the process. These beta particles interact with a phosphor layer applied to the little glass container that holds the tritium, making it glow continuously without any need for periodic exposure to an outside radiation source.

However, since the beta particles are the product of radioactive decay, the radioluminescent effect will gradually fade as more and more of the tritium decays into helium-3 and stops producing beta radiation. Tritium has a half-life of 12 years and change, and tritium-powered lamps are generally rated for 10 - 20 years of useful life, depending on the design. Aside from bombarding the helium-3 with high-energy neutron radiation (which you really don't want to try at home), there's no effective way to recharge a tritium-powered light source. Either the whole sight or the tritium element inside will need to be replaced.