Spin-Exchange Optical Pumping Of Solids

Spin-Exchange Optical Pumping of Solids

Brian Patton

In spin-exchange optical pumping (SEOP), angular momentum is transferred from photons to alkali atoms and then to the nuclei of another substance. The result is a material which can exhibit nuclear magnetizations many orders of magnitude larger than their equilibrium value. These "hyperpolarized" nuclei can then be used in studies of fundamental physics, NMR spectroscopy, or in vivo imaging.

Historically, the application of SEOP has been limited to the noble gas isotopes helium-3 and xenon-129. Recently, however, we have demonstrated that an optically pumped cesium vapor can polarize the cesium-133 nuclei of solid cesium hydride. Though the initial polarization enhancements have been modest -- a factor of twenty or so -- SEOP of solids may eventually become a very simple and effective way to produce polarized compounds. I will describe these initial experiments and compare the results to numerical simulations and to data from other cesium salts. I will also discuss the possibility of polarizing other nuclei (most notably hydrogen and lithium) with an optically pumped cesium vapor.