Progress Toward a Spin Exchange Pumped 3 He Neutron Spin Filter

Abstract

Polarization of ³He by spin exchange with laser optically pumped Rb vapor has advanced to a state of the art necessary for an effective, reliable, and relatively inexpensive broadband neutron spin filter. Over the past several years, many advances have led to the current state, most importantly advances in materials (glass), cell making including cleaning and gas purification, and the utilization of laser diode arrays. Most crucial, however, have been the many exciting experimental applications that motivate the technical developments. We provide details useful for implementing spin filter cell construction and filling and for optimal use of laser diode arrays, and we describe a neutron spin filter test set-up at the University of Michigan.