Improved Performance of the Munich Heavy Ion Postaccelerator

Improvement of the shunt impedance and of the phase acceptance of the Munich heavy ion postaccelerator are described. The shunt impedance has been increased by using slimmer drift tubes, by mounting more drift tubes and by installing a drift tube configuration with flat gap voltage distribution along the resonator axis. The phase acceptance has been increased by means of a three-harmonics double-drift buncher on the high-energy side of the tandem. The phase acceptance of the system buncherbooster is about 70%.