Comparison between Measurements and Orbit Code Simulations for Beam Instabilities due to Kicker Impedance in the 3-GeV RCS of J-PARC

Pranab Saha, Hiroyuki Harada, Naoki Hayashi, Hideaki Hotchi, Yoshihiro Shobuda, Fumihiko Tamura, Masanobu Yamamoto, Schaa, Volker RW (Ed.), Petit-Jean-Genaz, Christine (Ed.), Arduini, Gianluigi (Ed.), Michel, Peter (Ed.)
The transverse impedance of the extraction kicker magnets is the most dominant beam instability source in the 3-GeV Rapid Cycling Synchrotron of J-PARC. The instability occurs when chromaticity is fully corrected during acceleration but on the other hand no instabilities are observed for a full chromatic correction only at the injection energy even for a beam power up to 500 kW. However, the situation may change for a beam power of 1 MW and also for the upgraded injection beam energy from the
more » ... m energy from the present 181 MeV to the 400 MeV, as space charge effect in the non-relativistic region is believed to suppress the growth rate of beam instability. In order to study the kicker impedance in detail, recently we have introduced measured time dependent impedance source in the ORBIT simulation code in a realistic manner. The ORBIT code itself has also been well upgraded and given realistic features for application to synchrotrons. We have also carried out a systematic experimental study for a maximum beam power of 500 kW. In this paper, a detail comparison between measurements and corresponding simulations including 1 MW simulation results are presented.
doi:10.18429/jacow-ipac2014-tupri051 fatcat:duaspmytgrfxtcn4wf4mzu3dwi