Electron evaporation from magnetic trap in Troitsk nu-mass experiment

Abstract

This paper is dedicated to the simulation of the so-called trapping-effect observed in the Troitsk nu-mass experiment. The effect is caused by the magnetic trapping of decay electrons in the windowless gaseous tritium source and the gradual evaporation of those electrons. As a result, alongside regular tritium beta-spectrum electrons, we see additional electrons that are initially trapped in the source and escape it with changed energy. The spectrum of evaporated electrons is quite peculiar (almost flat for monochromatic initial electrons) and could not be directly measured in the experiment. So one has to rely on simulations. Also, it is possible that the same effect could be observed in other cases of magnetic traps.