Experimental beam tests to investigate LINAC component performance

An elaborate test set-up was prepared and beam tests were done to investigate the performance of beam focusing solenoids and buncher. The requirement for these tests was realized during the high power beam testing of the first 10 MeV, 5 kW industrial linac developed at RRCAT. The experimental set-up consisted of electron gun, buncher section of linac, collimator, beam focusing solenoid, microwave system, beam diagnostic systems and vacuum system. A small length of the linac section used in this experiment was decided such that the low energy beam behavior could be investigated without the constraint of it having to pass the full length of the linac. Several important leads about the focusing component errors and their possible mitigation were identified through these investigations. Moreover, the behavior of the beam just outside the buncher cavities could be investigated giving the information about capture efficiency of the section. Beam profile measurement under different conditions was used as the primary investigation tool. Several settings of the focusing elements were tested. Several decisions in the main project of linac development have been taken based on the test results of this set-up. This paper describes the salient features of the development activity and experimental results. (author)