Low Frequency Duty Factor Improvement for the CERN PS Slow Extraction Using RF Phase Displacement Techniques

The slow extraction spill from synchrotrons is modulated by residual ripple on the power supplies of magnetic elements. Stochastic RF methods. were proposed in the past to improve the poor duty factors of very long extractions (several minutes). Another method, based on RF phase displacement principle is presented here. It is particularly suitable for standard spill lenghts of the order of 1 sec. This operationally simple technique has been studied, tested and implemented on the CERN-PS and has improved the low frequency duty factor from 67 % to 98 % typically for up to 600 ms spills.