Characterization of a low-pressure high-capacity {sup 129}Xe flow-through polarizer

Journal Article · Tue Dec 15 00:00:00 EST 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.063424· OSTI ID:21352391

Schrank, G; Ma, Z; Schoeck, A; Saam, B ^[1]

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1. University of Utah, 115 S. 1400 E., Salt Lake City, Utah 84112 (United States)

We describe a low-pressure flow-through apparatus for generating hyperpolarized {sup 129}Xe and report its performance by examining both the output {sup 129}Xe polarization P{sub Xe} by NMR and the in situ Rb polarization profile by optically detected electron paramagnetic resonance. The polarizer is based on a previously presented design employing a long optical pumping cell, lean Xe mixture at low pressure, Rb presaturation, and counterflow of gas with respect to the direction of light propagation. The numerical model to which we compare the polarizer's performance includes the temperature dependence of the Rb-{sup 129}Xe spin-exchange rate, which has not previously been treated. The qualitative trends in the data mostly follow those in the model, although the model predicts P{sub Xe} to be up to a factor of two higher than observed. This discrepancy cannot be attributed to low Rb polarization: the model and the optically detected electron paramagnetic resonance data (acquired at six points along the length of the heated portion of the optical pumping cell) are in reasonable agreement and show typical values of 85%-95%, although measurements also reveal an anomalous region of depressed Rb polarization near the middle of the cell. The highest output {sup 129}Xe polarization P{sub Xe}=84+-16%, was recorded using approx =60 W of frequency-narrowed laser light at a Xe partial pressure (referenced to 20 deg. C) of 1.1+-0.2 mbar, flowing at 1 sccm of Xe; typical values were P{sub Xe}approx =20% flowing at 10 sccm of Xe with approx =30 W of laser light.

• OSTI ID: 21352391
• Journal Information: Physical Review. A, Vol. 80, Issue 6; Other Information: DOI: 10.1103/PhysRevA.80.063424; (c) 2009 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
COMPARATIVE EVALUATIONS
DESIGN
ELECTRON SPIN RESONANCE
LIGHT TRANSMISSION
NUCLEAR MAGNETIC RESONANCE
OPTICAL PUMPING
PARTIAL PRESSURE
PHOTON-ATOM COLLISIONS
POLARIZATION
RUBIDIUM
SPIN EXCHANGE
TEMPERATURE DEPENDENCE
VISIBLE RADIATION
XENON
XENON 129
ALKALI METALS
ATOM COLLISIONS
COLLISIONS
DAYS LIVING RADIOISOTOPES
ELECTROMAGNETIC RADIATION
ELEMENTS
EVALUATION
EVEN-ODD NUCLEI
FLUIDS
GASES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAGNETIC RESONANCE
METALS
NONMETALS
NUCLEI
PHOTON COLLISIONS
PHYSICAL PROPERTIES
PUMPING
RADIATIONS
RADIOISOTOPES
RARE GASES
RESONANCE
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
TRANSMISSION
XENON ISOTOPES