We find that if solid xenon is formed from liquid xenon, denoted "ice", there is a 10% increase of 129Xe longitudinal relaxation T1 time (taken at 77 K and 2 Tesla) over a trickle-freeze formation, denoted "snow". Forming xenon ice also gives unprecedented reproducibility of 129Xe T1 measurements across a range of 77-150 K. This temperature dependence roughly follows the theory of spin-rotation mediated by Raman scattering of harmonic phonons (SRRS), though it results in a smaller-than-predicted spin-rotation coupling strength cK0/h. Enriched ice 129Xe T1 experiments show no isotopic dependence in bulk relaxation mechanisms at 77 K and at kilogauss fields.
@article{arxiv.1607.01072,
title = {Robust solid $^{129}$Xe longitudinal relaxation times},
author = {M. E. Limes and Z. L. Ma and E. G. Sorte and B. Saam},
journal= {arXiv preprint arXiv:1607.01072},
year = {2016}
}