The Bevalac long spill

The Bevalac extraction time was increased from 1 to a maximum of 9.5 seconds, thus increasing the synchrotron duty factor and the data rate for experiments by a factor of 2-3, depending on the magnetic field. This slow rate of extraction required improved control of beam time structure, since magnet ripple remained approximately constant while the spill rate was decreased. Measurements of spill structure for the long spill are presented. Changes made to the accelerator systems are described, as well as tuning procedures found to be necessary, and the ultimate hardware limits found for the spill length. >