Development of a spin-polarized positron source

Kawasuso, Atsuo; Fukaya, Yuki   ; Maekawa, Masaki; Yabuuchi, Atsushi

Positrons emitted from beta-plus emitters are longitudinally spin polarized. To use spin-polarized positrons in the future materials science, we develop a spin-polarized positron beam. The spin-polarization increases with the Q-value of beta-plus emitter. We thus develop a Ge-Ga positron source. We irradiate high energy protons to the Ga stable isotope and obtain Ge-Ga through the nuclear reaction. We report the optimum condition of proton irradiation and design of the source capsule.