Development of a polarized He-3 system for experiments on time-reversal invariance in nuclear reactions

A polarized He-3 system is being developed for an experiment on time-reversal invariance in nuclear reactions. Spin-exchange optical pumping is employed to polarize the He-3 nuclei. A quartz glass cell and a sapphire cell are used as containers for the He-3. With the pulsed neutron beam at High Energy Accelerator Research Organization (KEK), the polarizations of He-3 were measured for the quartz glass cell and the sapphire cell at a He-3 pressure of 3 atm by employing a frequency-narrowing technique based on an external-cavity and were found to be 0.538 +/- 0.004 +/- 0.02 v and 0.627 +/- 0.002(stat) +/- 0.01(sys) respectively.