2018 年 28 巻 4 号 p. 204-207
Neutron guides are one of the devices to transport neutron beam for long distance without sacrificing much neutrons, it can supply neutrons to many experimental instruments distributed in a large experimental hall. Also, by using a curved guide, only the neutrons in a required energy range can be transported, and gamma rays and fast neutrons can be effectively eliminated, therefore the signal to background ratio is improved. In addition, a neutron beam can be branched by applying curved guides which include compact multichannel bender using supermirrors. Neutron guides are also used to control the divergence angle and intensity of the neutron beam supplied to the neutron instruments. Typical example is the single crystal diffractometer, SENJU, installed at J-PARC.