Production of hyperpolarized xenon in a static pump cell: Numerical simulations and experiments

Abstract

Hyperpolarized 129 Xe finds numerous applications in NMR spectroscopy and magnetic resonance imaging. The production of hyperpolarized 129 Xe by spin-exchange optical pumping is therefore an important experimental issue. We model the three-dimensional transport processes within a so-called batch mode pump cell via numerical finite element method simulations and compare the results with experimental data. In particular, the influence of different experimental parameters, such as temperature, xenon and nitrogen partial pressure, laser power, and radius-to-length ratio of a cylindrical pump cell, is evaluated. The developed numerical method is capable of describing the spin-exchange optical pumping process in a realistic manner.

Direct observation of atomic diffusion in warm rubidium ensembles

“…Given the recent applications of hyperpolarized 129 Xe in medical imaging, we hope that the precise value of this diffusion coefficient will help optimize setups like the one presented in Ref. [27].…”

Generation of laser-polarized xenon using fiber-coupled laser-diode arrays narrowed with integrated volume holographic gratings

“…P Xe would generally be expected [8,9,24,25] to decrease smoothly and dramatically with increasing Xe density; the xenon polarization becomes 'capped' by corresponding reductions in the values of P Rb that can be achieved (given the strong contribution to the Rb spindestruction rate from increased Rb/Xe collisions [1,26]). Thus, most AMSE OP setups typically employ relatively low running Xe partial pressures ($1-70 torr) to achieve high (>10%) P Xe values-potentially limiting some applications that simultaneously require both high Xe densities/amounts and high P Xe .…”

Interdependence of in-cell xenon density and temperature during Rb/129Xe spin-exchange optical pumping using VHG-narrowed laser diode arrays

“…However, this set of curves also demonstrates the utility of optical pumping at T OPT , as the highest steady-state 129 Xe signals were achieved at the optimal cell temperature for this Xe loading (85°C for 500 torr Xe). More generally, larger c SE values should translate to higher P Xe values-to a point: once the Rb density grows too high, poor illumination of the rear and outer portions of the cell volume will cause the overall hP Rb i to fall [34,46] (as 'dark' Rb is essentially unpolarized)-capping the value of P Xe that can be achieved. Moreover, at the highest temperatures (e.g.…”