4 research outputs found
Collisional EPR Frequency Shifts in Cs-Rb-Xe Mixtures
We report a measurement of the ratio of dimensionless enhancement factors
for Cs-Xe and Rb-Xe in the temperature range
115-140\, ^{\circ}C; both pairs are used in spin-exchange optical pumping
(SEOP) to produce hyperpolarized Xe. characterizes the
amplification of the Xe magnetization contribution to the alkali-metal
electronic effective field, compared to the case of a uniform continuous medium
in classical magnetostatics. The measurement was carried out in "hybrid" vapor
cells containing both Rb and Cs metal in a prescribed ratio, producing
approximately the same vapor density for both. Alternating measurements of the
optically detected EPR frequency shifts caused by the SEOP polarization and
subsequent sudden destruction of the same quantity of Xe magnetization
were made for Cs and either Rb or Rb. An important source
of systematic error caused by power fluctuations in the pump laser that
produced variable light shifts in the EPR frequency was characterized and then
mitigated by allowing sufficient warm-up time for the pump laser. We measured
with no
apparent temperature dependence. Based on our previous measurement
, we determine , more precise than but consistent with a previous measurement made by
another research group.Comment: 10 pages, 7 figures, 47 reference