Preliminary studies on longitudinal beam dynamics for a 1 GeV proton accumulation ring

1 GeV proton Accumulator Ring is currently being designed for the proposed Indian Spallation Neutron Source (ISNS) at Raja Ramanna Centre for Advanced Technology. In order to perform the longitudinal beam dynamics studies for this machine, a computer program has been developed. In low loss machine such as Accumulator Ring, for minimizing longitudinal capture loss, proper chopped beam is required from the injector linac. Using this program, the beam capture efficiency for different chopping profiles (i.e. for different rise, fall times of chopper etc.) of the injected beam is studied. Based on these studies, the requirement on beam chopping is analyzed. In addition, the developed computer program also studies the improvement in the bunching factor for the proton beam in the Accumulator Ring by using higher harmonic RF cavity in addition to fundamental frequency RF cavity. Full 6D beam tracking is possible by coupling this program to the readily available software MAD8 using C library. The paper discusses the details of these studies. (author)