Bunching of the slow positron beam produced using s-band electron linac at ISIR, Osaka Univ

A pulsing system of slow positron beam has been developed in order to measure positron lifetime for thin films. Positrons are produced using a S-band electron linac. The pulsing apparatus consists of positron storage section, chopper and bunching section. The storage section has been equipped to reduce the energy width and make a quasi-continuous beam. Positrons are bunched by suitable time-varying voltage which is produced by an arbitrary waveform generator and a following amplifier and is periodically applied to the bunching electrode. The time width of bunched positrons has reached ∼780 ps (FWHM) with positron mean energy of ∼100 eV at present. (author)