Surface relaxation mechanisms of laser-polarized 129Xe.
Surface relaxation mechanisms of laser-polarized 129Xe.
复制标题
激光偏振 129Xe 的表面弛豫机制。
作者：
Driehuys;Cates;Happer
We have determined the dominant mechanism for nuclear spin relaxation of laser-polarized ${}^{129}mathrm{Xe}$ in silicone coated cells. The ${}^{129}mathrm{Xe}$ relaxation rate is found to be strongly dependent on magnetic field, which indicates that ${}^{129}mathrm{Xe}$ becomes trapped in the coating for extraordinarily long times ( $ensuremath{ au}g10ensuremath{mu}$s). Relaxation is caused by dipolar coupling between the trapped ${}^{129}mathrm{Xe}$ and the protons in the coating, which we confirm with a novel double resonance scheme. This result should aid the development of improved coatings, and offers new possibilities for using laser-polarized ${}^{129}mathrm{Xe}$ as a probe of other polymer and biological systems.
We have determined the dominant mechanism for nuclear spin relaxation of laser-polarized ${}^{129}mathrm{Xe}$ in silicone coated cells. The ${}^{129}mathrm{Xe}$ relaxation rate is found to be strongly dependent on magnetic field, which indicates that ${}^{129}mathrm{Xe}$ becomes trapped in the coating for extraordinarily long times ( $ensuremath{ au}g10ensuremath{mu}$s). Relaxation is caused by dipolar coupling between the trapped ${}^{129}mathrm{Xe}$ and the protons in the coating, which we confirm with a novel double resonance scheme. This result should aid the development of improved coatings, and offers new possibilities for using laser-polarized ${}^{129}mathrm{Xe}$ as a probe of other polymer and biological systems.