Local Magnetic Field Shift in Liquid and Solid Xenon
1966; American Institute of Physics; Volume: 150; Issue: 1 Linguagem: Inglês
10.1103/physrev.150.174
ISSN1536-6065
Autores Tópico(s)Advanced MRI Techniques and Applications
ResumoAdditional nuclear-magnetic-resonance measurements have been made of the temperature and density dependence of the average local magnetic field at ${\mathrm{Xe}}^{129}$ nuclei in liquid and solid xenon samples in an external magnetic field ${H}_{0}$. We have extended the temperature range of our solid measurements down to 21\ifmmode^\circ\else\textdegree\fi{}K, and a computer of average transients has been used to improve the signal-to-noise ratio and reduce the effects of random errors. Our new liquid data covering the density range from 423 amagat to the triple point at 523 amagat show a linear dependence of the local field on density. The rate of increase of this local field with liquid density is 5.66 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}7}$ ${H}_{0}$ G/amagat. The new data for the extended solid range from 577 amagat (triple point) to 639 amagat (21\ifmmode^\circ\else\textdegree\fi{}K) show a nonlinear density dependence. The rate of increase of the local field with solid density $\ensuremath{\rho}$ is $5.10\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}{H}_{0}\ensuremath{-}7.42\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\ensuremath{\rho}{H}_{0}$ G/amagat. The new data confirm the previously established discrepancy between the solid density dependence measured in this laboratory and the dependence measured by Yen, Norberg, and Warren. This discrepancy remains unexplained.
Referência(s)