Highly polarized cold neutron beam obtained by using a quadrupole magnet

Oku, Takayuki   ; Yamada, Satoru; Shinohara, Takenao   ; Suzuki, Junichi; Mishima, Kenji*; Hirota, Katsuya*; Sato, Hiromi*; Shimizu, Hirohiko

We have studied a neutron polarization method by means of a quadrupole magnet. By passing through the aperture of the quadrupole magnet (QM), positive and negative polarity neutrons are accelerated in opposite directions and spatially separated due to the magnetic field gradient. Then, by extracting one spin component, we can obtain a highly polarized neutron beam. Since polarized neutrons do not interact with any substances in this method, we can obtain the polarized neutron beam free from neutron attenuation. As a result of a cold neutron beam polarization experiment by using the QM, we obtained extremely high neutron polarization degree P0.999. In this paper, we show some experimental results of the neutron polarization experiment and discuss the application of the QM-based polarizing device to neutron scattering experiments.