Role of plasmons in the LISA test-mass charging process

High-energy particles of galactic and solar origin will charge the test-masses on board laser interferometer space antenna (LISA) and other interferometers for gravitational-wave detection in space. The stochastic noise associated with this charging process is estimated to limit the sensitivity of space interferometers at low frequencies. In a previous paper we have reported a detailed study of low-energy electromagnetic processes affecting the LISA test-mass charging. In particular, we have discussed ionization and electron kinetic emission due to electrons and ions, while the role of plasmons in generating low-energy electrons has been deemed as negligible. Recently, the decay of plasmons has been observed to modify the energy distribution of electrons emitted by ions incident on foils of carbon and gold. Our work is consolidated here accordingly. The contribution of plasmon decay will be considered in future Monte Carlo simulations of LISA test-mass charging in the energy range of a few eV in addition to electron quantum diffraction and backscattering.