Beam stacking experiments at the ion accumulation ring TARN

The ion beam accumulation ring TARN was constructed at INS in 1979. In this ring the combination of multiturn injection and rf stacking has been employed to store the beam in the horizontal betatron and in the longitudinal synchrotron phase space. In the experiments, twenty turns of beam were injected into a betatron phase space area of 153 π mm mrad, and about 20 pulses were stacked in the synchrotron phase space area with a fractional momentum spread, ΔP/ P, of 2.3%. An overall stacking number of about 300 turns was attained. The repetition rate of the rf stacking was 30 Hz and it required approximately 0.5 s to fill the four-dimensional phase space area with beam. In the present paper, the results of the beam accumulation experiments are given and then compared with those of computer simulations.