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Title: Optical pumping of Rb in the presence of high-pressure sup 3 He buffer gas

Journal Article · · Physical Review A. General Physics; (United States)
 [1];  [2]; ; ;  [3]
  1. Simon Fraser University, Burnaby, British Columbia (Canada)
  2. Simon Fraser University, Burnaby, British Columbia (Canada) TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia (Canada)
  3. TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia (Canada)

A cryogenic technique has been used to produce polarized {sup 3}He targets of up to relative density {ital p}=12 atm ({approx}3{times}10{sup 20} {sup 3}He atoms/cm{sup 3}; {ital p}=1 atm corresponds to 760 Torr or 101.3 kPa pressure at 273 K). In these targets {sup 3}He nuclei are polarized by spin-exchange collisions with optically pumped rubidium atoms. From transmission measurements at wavelengths of 790--800 nm, we have determined pressure shifts, linewidths, and line-shape asymmetries for the Rb 5{ital S}{sub 1/2}{r arrow}5{ital P}{sub 1/2} {ital D}1 transition. The Rb spin-destruction rate was found to exhibit a quadratic increase versus {sup 3}He pressure, which indicates the importance of Rb-{sup 3}He-{sup 3}He collision processes. The transmission results for circularly polarized light are well described by a model that predicts the dependence of the average Rb polarization on Rb density, {sup 3}He pressure, light intensity, and cell geometry. The Rb-{sup 3}He spin-exchange cross section, {l angle}{sigma}{sub SE}{ital v}{r angle}=6.1{times}10{sup {minus}20} cm{sup 3} s{sup {minus}1}, was found to be independent of {sup 3}He pressure up to {ital p}=12.1 atm. Maximum {sup 3}He polarizations of 72--79% were observed with cells of 17 cm{sup 3} volume that contained {sup 3}He at {ital p}=6--9 atm.

OSTI ID:
5151824
Journal Information:
Physical Review A. General Physics; (United States), Vol. 44:5; ISSN 1050-2947
Country of Publication:
United States
Language:
English