Neutron Spin Echo Spectrometers for J-PARC with Resonance Spin Flippers

Abstract

Neutron spin echo (NSE) methods with resonance spin flippers have been developed for 10 years. There are two types of spin echo methods using resonance spin flipper: Neutron resonance spin echo (NRSE) and Mieze. For spallation neutron source like J-PARC, provided that high-frequency neutron spin flippers and appropriate calibration for field integral are realized, NRSE is more suitable than conventional spin echo method since, (1) NRSE can be small and hence it is possible to install two or more spectrometers in one beam line, (2) magnetic shielding over precession region, which is expected to be necessary under huge iron shielding around the sputter source, is possible. The authors suggest a set of NRSE spectrometers and Mieze spectromter sharing one beam line, in which neutrons are separated according to their wavelength range. This system will cover very wide range of Fourier time and will open new applications to NSE method.