Operating experience of the upgraded university of Rochester MP tandem

Overview & Synopsis

The upgrading program for the MP Van de Graaff accelerator at the University of Rochester has been developed with several novel and unique features. We describe the operating experience of the accelerator with particular emphasis on the performance of the cryogenic terminal pumping, the titanium electrode spiral inclined field acceleration tubes, and the overall accelerator transmission and voltage performance with a variety of high current heavy ion beams. The design features of the acceleration tubes are described, and the performance of the tubes is presented with regard to static voltage-holding ability and conditioning procedures, as well as operation with beam. Dependable operation exceeding 12MV on terminal has been achieved. The transmission of the accelerator has been measured for a variety of ion beams up to 197Au. Several charge states of each beam were momentum-analyzed, and the results are compared with predicted stripper yields. The transmission performance with 197Au in the range of 8-10 MV terminal voltage was 30-50 %.