PROGRESS ON THE ISIS SYNCHROTRON LOW POWER RF SYSTEM UPGRADE

The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK now routinely uses a dual harmonic RF system to accelerate beam currents in excess of 230µA to run two target stations simultaneously. In order to give more stable control of the phase of the RF voltage at each of the fundamental (1RF) and second harmonic (2RF) cavities, changes have been made to the low power RF (LPRF) control systems. A new FPGA based master oscillator has been implemented using a National Instruments FlexRIO FPGA module. This has allowed a relatively rapid deployment for various modules and functionality of the LPRF system, including a replacement master oscillator, which has now been commissioned with beam for the first time. This paper reports on the commissioning of the FPGA master oscillator (MO) and plans for the gradual replacement of remaining parts of the LPRF system.