Longitudinal phase space computer simulation of IUCF cooler ring multiturn stacking injection

The longitudinal phase space computer simulation of multiturn RF stacking injection and the preliminary experimental results of stacking at the IUCF (Indiana University Cyclotron Facility) are discussed. The simulation considered effects such as oscillatory ripples on the cooling stack orbit due to the debunching RF voltage, finite slew rate of RF modulations, and compromised choices of bucket height, debunching linearity, and deceleration speed. The simulation was found to be very helpful in gaining a quantitative understanding of RF stacking and was also found to be instrumental in specifying software and hardware parameters. Also reported is a 120-MeV polarized proton test, during which about 50 nA of beam was stacked and cooled with six turn injections. Results indicate that the stacked beam could only survive a limited number of kicker firings