Astroparticle physics with tritium

Assuming that the value of the neutrino mass is lower than the sensitivity of the KATRIN experiment, far more complicated experiments will be necessary in the future to finally solve the mystery of the neutrino mass. For this purpose, fundamentally new technologies will have to be applied, which concern both the type of measurement and the type of source. One step would be to use an atomic (T) instead of a molecular (T₂) tritium source. The challenge is to produce atomic tritium on a large scale, to cool it and to store it without recombination (e.g. Project8). The tritium laboratory offers ideal conditions for such development work due to its experience in operating the KATRIN source and the possibilities offered by the closed tritium cycle.

Tritium is not only the key to access direct measurements of the neutrino mass, but also to further fundamental questions of astroparticle physics.

Sterile neutrinos are candidates for so-called warm dark matter. If these hypothetical particles exist, they would leave a specific signature at their characteristic mass in the tritium-beta spectrum. In order to detect these signatures, experiments are needed which, like KATRIN, measure the spectrum. However, the systematics and challenges are different.
In order to meet these challenges, new technologies are being developed at the tritium laboratory in cooperation with partners.

The ultimate breakthrough in astroparticle physics would be a direct detection of (relic) neutrinos, which were created one second after the Big Bang and whose density today is about 300 per cm³. Tritium could again play a key role in this. Relic neutrinos could be trapped in the tritium nucleus and then generate a monoenergetic electron with an energy just above the beta spectrum. The challenge lies on the one hand in the energy resolution necessary to detect these rare events, and on the other hand in the large amount of tritium (~100 g) that has to be used (e.g. ptolemy). The experience and capabilities of the tritium laboratory are indispensable to meet these demanding challenges.