Superconductivity and cryogenics for linear accelerator programme at IUAC, New Delhi

The Inter-University Accelerator Center, New Delhi is involved in commissioning a superconducting linear accelerator (LINAC) as a booster to its existing 15 UD Pelletron accelerator. The booster consists of three LINAC modules, each containing eight superconducting Nb quarter wave resonators and a superconducting solenoid magnet. The first LINAC module preceded by a superbuncher with one cavity and followed by a rebuncher cryostat with two cavities was installed in 0° beam line of Pelletron and has been under operation for some time at the Center. The module is integrated with a liquid helium (LHe) refrigerator through a cryogen valve box and the distribution line. The performance tests of each component like the RF cavity, the cryomodule and the liquid helium distribution line were carried out independently prior to the beam acceleration test. After having many trial runs on this integrated cryonetwork system, beam acceleration tests were performed during 2007. The energy of silicon beam with charge state of +10 has been enhanced approximately from 130 MeV to 158 MeV using the first module with seven effective cavities and the accelerated beam was delivered at user’s scattering chamber. The present paper highlights the performance of the first module producing an accelerating beam duly bunched in the rebuncher. The performance of first LINAC cryomodule along with problems and the solution associated with the cryogenic system and the cavities encountered during the beam runs are presented in this paper.