Studies of accumulation rate of H atoms in solid ${\mathrm{H}}_{2}$ films exposed to 0.1 and 5.7 keV electrons

Studies of accumulation rate of H atoms in solid $H_{2}$ films exposed to 0.1 and 5.7 keV electrons

S. Sheludiakov, C. K. Wetzel, D. M. Lee, V. V. Khmelenko, J. Järvinen, J. Ahokas, and S. Vasiliev

Phys. Rev. B 107, 134110 – Published 17 April 2023

Abstract

In this work, we report on electron spin resonance studies of H atoms stabilized in solid $H_{2}$ films at temperature $0.1$ and $0.7 K$ and in a magnetic field of $4.6 T$ . We produced H atoms by two different techniques: bombarding $H_{2}$ films by $0.1 keV$ electrons generated during an rf discharge run in the sample cell or exposing $H_{2}$ films to a flux of $5.7 keV$ electrons released during tritium decay. We observed a faster H atom accumulation in the films made of $H_{2}$ gas with a small initial ortho- $H_{2}$ content (0.2–3%) as compared with those made from the gas with a higher initial ortho- $H_{2}$ admixture. The accumulation rate difference was about 70% for the samples exposed to high energy electrons and about an order of magnitude for the samples bombarded by low-energy electrons. We propose possible explanations for the observed behavior.