An In-situ He-3 Polarizer, a Noble Hybrid RF Spin Flipper, and a Two-coil Spin Flipper Deigned for Polarized Neutron Instruments

For possible implementations of a He-3 based neutron polarizer at the neutron beam lines of HANARO (High-Flux Advanced Neutron Research Reactor), we are developing a He-3 polarizer, a RF spin flipper, and a two-coil spin flipper. A compact in-situ He-3 polarizer was developed to maintain a constant neutron polarization in the neutron beam line during experiments. To have better control of neutron spins under stray magnetic field environments, a noble hybrid RF spin flipper with a high gradient magnetic field and a magnetic field compensation capability has been designed based on DC coils and permanent magnets. The detailed characteristics of the in-situ He-3 polarizer and the design criteria of the spin flippers are presented. The developed compact in-situ He-3 polarizer, the hybrid RF flipper, and the two-coil spin flipper system can be a useful option for implementing a polarization analysis capability in various polarized neutron instruments. With minor modifications for optimization, the developed neutron polarization optics could be applied for a polarized neutron reflectometer, a polarized SANS, a polarized neutron imaging, and a polarized neutron diffractometer