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A neutron polarizer-analyzer system based on polarized 3 He is being developed at KEK Pulsed Neutron Source for an experiment on time reversal invariance in the nuclear reaction at J-PARC. [ABSTRACT FROM AUTHOR]

A test of polarization of 3He nuclei via spin-exchange collisions with optically pumped rubidium atoms in an extremely low applied magnetic field was carried out. Permalloy magnetic shields were used to prevent a fast relaxation of 3He polarization owing to the inhomogeneity of a surrounding magnetic field. The whole installation was placed at the neutron beam line of the IBR-30 facility, and used as a neutron spin filter. Thus, a prototype of new design of neutron polarizer was introduced. We intend to apply this experience for the full-scale KaTRIn facility to test the time reversal violation in neutron-nuclear reactions. [Copyright &y& Elsevier]

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