The role of low-energy electrons in the charging process of LISA test masses

TL;DR

This study investigates how low-energy electrons interact with gold surfaces, affecting spacecraft charging and malfunction, by combining Monte Carlo simulations and ab-initio calculations to understand electron emission spectra.

Contribution

It introduces a novel combined Monte Carlo and ab-initio approach to model low-energy electron interactions with gold, relevant for spacecraft charge management.

Findings

Results align with experimental data and GEANT4-DNA simulations.

Energy spectrum of emitted electrons characterized across different energies.

Highlights the significance of low-energy electrons in spacecraft charging processes.

Abstract

The space environment encountered by operating spacecraft is populated by a continuous flux of charged particles that penetrate into electronic devices inducing phantom commands and loss of control, eventually leading to satellite failure. Moreover, electron static discharge that results from secondary electron emission of the device materials can also be responsible for satellite malfunction. In this regard, the estimate of the total electron yield is fundamental for our understanding of the test-mass charging associated with galactic cosmic rays in the LISA Pathfinder mission and in the forthcoming gravitational wave observatory LISA. To unveil the role of low energy electrons in this process owing to galactic and solar energetic particle events, in this work we study the interaction of keV and sub-keV electrons with a gold slab using a mixed Monte Carlo and ab-initio framework. We determine the energy spectrum of the electrons emerging from such a gold slab hit by a primary electron beam by considering the relevant energy loss mechanisms as well as the elastic scattering events. We also show that our results are consistent with experimental data and Monte Carlo simulations carried out with the GEANT4-DNA toolkit.