Measurement of polarization of He-3 with mobile polarized He-3 neutron spin filter

Abstract

A mobile polarized He-3 neutron spin filter was developed for both optical pumping and transportation, and the polarization of He-3 was measured with cold neutrons of HANARO in KAERI. The progress of polarization build-up during the optical pumping of the He-3 cell was observed by adiabatic fast-passage NMR system. The He-3 cell was made of an alumino-silicate glass GE-180 with a cylindrical shape of 40 mm in diameter and 60 mm in length from KEK. A cell contained 5.74 bar.cm of He-3 gas. The whole installation after 8 h pumping was transported to the general-purpose test station of the HANARO research reactor and the polarization of He-3 was measured with cold neutrons. The measured polarization of He-3 was 0.18 +/- 0.01 by measuring the neutron transmission through the He-3 cell.