Gamma-ray-induced positron annihilation spectroscopy at UVSOR-III BL1U

Taira, Yoshitaka*; Okano, Yasuaki*; Hirade, Tetsuya  

BL1U is a beamline that researches the development of new light sources and the exploration of usage methods. We are generating 6.6 MeV ultrashort pulse gamma rays using a Ti: Sa laser with a wavelength of 800 nm and are researching gamma ray-induced positron annihilation spectroscopy (GiPALS). GiPALS is a method that measures the lifetime of positrons by measuring the emission time distribution of annihilation gamma rays and can analyze the type and size of defects inside a sample. GiPALS is available to users for in-situ measurements of defect formation in metallic materials during stress loading and measurements of bulk samples such as ferrous materials, catalytic materials, and scintillators.