Stop-Flow SEOP Polarizer for 129Xe.

In the view of growing application of hyperpolarized xenon in various fields of science and medicine, the availability of relatively low cost, reliable polarizers is of the utmost importance. The article describes the design and construction of the spin exchange optical pumping (SEOP) polarizer for ¹²⁹Xe, operating in the stop-flow mode. Using 9 W of laser power at the input of 1 litre optical pumping cell, a single batch of the gas mixture is polarized in about 15 minutes. The xenon nuclear polarization is calibrated against the thermally polarized water and xenon phantoms. It reaches about 40 % in the gas mixture containing 3 % of isotopically enriched xenon. The hyperpolarized xenon is accumulated in the detachable liquid nitrogen dewar containing 0.6 T Halbach magnet with the cold trap inside. All components that are important for the effective operation of the system are described in detail, and possible improvements are pointed out. [ABSTRACT FROM AUTHOR]