Optimization of Multi-turn Injection into a Heavy-ion Synchrotron Using Genetic Algorithms

For heavy-ion synchrotrons an efficient multi-turn injection (MTI) from the injector linac is crucial in order to reach the specified currents using the available machine acceptance. The beam loss during the MTI must not exceed the limits determined by machine protection and vacuum requirements. Especially for low energy and intermediate charge state ions, the beam loss can cause a degradation of the vacuum and a corresponding reduction of the beam lifetime. In order to optimize the MTI a genetic algorithm based optimization is used to simultaneously minimize the loss and maximize the multiplication factor (e.g. stored currents in the synchrotron). The effect of transverse space charge force on the MTI has also been taken into account. The optimization resulted in injection parameters, which promise a significant improvement of the MTI performance for intense beams in the SIS18 synchrotron at GSI.