OPERATION TESTS of the 260 MHz 1500 W SOLID STATE RF AMPLIFIER at TARLA FACILITY

Abstract

Turkish Accelerator and Radiation Laboratory (TARLA) will be the first accelerator-based user facility in Turkey. The facility is under construction at the Institute of Accelerator Technologies of Ankara University. Based on the state-of-art superconducting technology, TARLA accelerator offers a multi-experimental facility providing a variety of accelerator-based radiation sources for users coming from various fields like chemistry, physics, biology, material sciences, medicine and nanotechnology. TARLA consists of two acceleration lines: the first one is the injector that provides high current continuous wave (CW) electron beam at 250 keV energy, and the second one is the main accelerator that comprises of two superconducting (SC) cryomodules separated by a bunch compressor in order to accelerate the electron beam up to 40 MeV energy. Two normal conducting accelerators, so called subharmonic (SHB) and fundamental (FB) buncher cavities whose operation frequencies are 260 and 1300 MHz, respectively, are used to compress the electron bunches from ~600 ps to ~10 ps. SHB cavity is powered by a 1500 W Radio-frequency (RF) power amplifier. Currently, the electron gun training, and superconducting modules acceptance tests, personal safety system, and helium cryogenic system commissioning tests are performed simultaneously. In this study, we present the operation tests of the 1500 W RF amplifier in the scope of the commissioning tests of injector line which showed phase drift coefficents of ~0.5 deg/Co and ~0.67 deg/Co in repeated tests. Moreover, the importance of constancy of the water pressure in the water-cooling line for phase constancy of the delivered power has become evident as a result of current obervations.