Development status of the NMR system for the polarized ³He neutron spin filter (NSF) in the MLF at J-PARC

For realizing convenient ³He neutron spin filters (NSF), a nuclear magnetic resonance (NMR) system is indispensable for frequently monitoring the ³He polarization P of the NSF, regardless of the neutron beam properties. A flexible NMR system combining adiabatic fast passage (AFP) and pulse NMR methods on the basis of their complementary relationship was proposed and fabricated for the ³He NSF in the Materials and Life science experimental Facility at J-PARC. We demonstrated that the fabricated system could deduce P not only from AFP but also from pulse NMR signals. In addition, we mentioned the possibility that the system could evaluate P of ³He NSFs in various shapes using the measured NMR signal of a proton in water. (author)