Integrated RF system for positron annihilation lifetime spectrometer

Positrons can probe material defects with low concentrations and high sensitivity. The positron annihilation lifetime spectroscopy (PALS) is an established research methodology for investigation of atomic level defects in polymers, porous materials, metals, semiconductors etc. Conventional PALS lacks depth selectivity, and so tunable energy slow positron beams are used to get depth selective information. A pulsed slow positron beam based depth selective PALS is designed and developed in BARC, which employs an integrated RF system to power its beam line structures. The multi frequency integrated indigenous RF system derives its signal input from one common source and thereafter splits the same in three branches. Each of these branches include one RF amplifier, splitter, attenuator, phase shifters, isolators, DC blocks, matching circuits and RF loop couplers that couple the RF power to each of pulsed positron beam line structures. This article gives details of integrated RF system designed, developed and coupled with positron beam based PALS of RCD, BARC. (author)