Development of spin flippers with steady current for the TOF-NSE spectrometer at a pulsed spallation neutron source

We designed π and π/2 flippers for a time-of-flight neutron spin echo (TOF-NSE) spectrometer at a pulsed spallation neutron source. The flippers operate with steady current for a white neutron beam. The π flipper consists of a compact modified current sheet and Helmholtz coils. This modified current sheet produces magnetic fields parallel to the sheet surface without magnetic fields perpendicular to the sheet surface at the surface of the sheet for a large neutron beam cross section. The π/2 flipper consists of a rectangular coil and Helmholtz coils. We present the results of performance tests of the new-type π flipper.