Electron evaporation from magnetic trap in Troitsk nu-mass experiment

TL;DR

This paper simulates the trapping-effect in the Troitsk nu-mass experiment, where magnetic trapping causes evaporation of decay electrons, affecting the observed electron spectrum, which cannot be directly measured and requires detailed modeling.

Contribution

The paper presents a detailed simulation of the trapping-effect and electron evaporation in a magnetic trap, providing insights into the spectrum alterations in the Troitsk nu-mass experiment.

Findings

The trapping-effect causes additional electrons with altered energies.

The evaporated electron spectrum is nearly flat for monochromatic initial electrons.

Simulation results help interpret the experimental data and could apply to other magnetic traps.

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.