Tune measurement in the APS rings

The APS system will contain three rings. The first is a positron accumulator ring(PAR). Its function is to coalesce 24, 30-ns-long positron bunches into one 290-ps bunch. The second is the injector synchrotron (IS). It accelerates the 450-MeV positron bunches to 7 GeV for injection into the storage ring(SR). Five IS bunches are accumulated into one SR bucket to produce 17.5-nC, 60-ps bunches. Twenty buckets will be filled in the SR to give a current of 100 mA.<>