Comment on "Pressure dependence of wall relaxation in polarized He^3 gaseous cells." by W. Zheng, H. Gao, Q. Ye, and Y.Zhang

TL;DR

This paper critiques a study on how pressure affects helium-3 relaxation times, questioning the boundary condition used and proposing alternative explanations for the observed pressure dependence.

Contribution

It challenges the original boundary condition assumption and offers alternative theoretical explanations for the pressure dependence of He^3 relaxation times.

Findings

Linear pressure dependence observed in relaxation times

Questions boundary condition validity

Suggests alternative explanations for the effect

Abstract

The authors have demonstrated a strong linear pressure dependence of the longitudinal relaxation time for He^3 at room and cryogenic temperatures in a given experimental setup. They offer a theoretical explanation of the effect based on diffusion theory in the bulk and an unusual boundary condition. We question the physical basis of the boundary condition and suggest some alternate explanations of the observations.