First Results from the use of Dual Harmonic Acceleration on the ISIS Synchrotron

The ISIS facility at the Rutherford Appleton Laboratory in the UK is currently the most intense pulsed, spallation neutron source. The accelerator consists of a 70 MeV H-linac H-linac H-linac and an 800 MeV, 50 Hz, rapid cycling, proton synchrotron. The synchrotron beam intensity corresponds to a mean current of 200 μA. The synchrotron beam is accelerated using six, ferrite loaded, RF cavities with harmonic number 2. Four additional, harmonic number 4, cavities have been installed to increase the beam bunching factor with the potential of raising the operating current to 300 μA. This paper reports on the hardware commissioning and the first beam tests.