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Persistent URL http://purl.org/net/epubs/work/37912
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Record Id 37912
Title Progress on dual harmonic acceleration on the ISIS Synchrotron
Abstract The synchrotron beam intensity in ISIS is 2.5E13 protons per pulse, corresponding to a mean current of 200 µA. The synchrotron beam is accelerated using six, ferrite loaded, RF cavities with harmonic number 2, swept in frequency from 1.3 MHz to 3.1 MHz during acceleration. Four additional, harmonic number 4, cavities have been installed to increase the beam bunching factor with the potential to raise the mean operating current to 300 µA. The relative amplitude and phasing of the new second harmonic cavities are carefully controlled to evenly distribute protons throughout the beam pulse and therefore minimise the peak pulse intensity early in the acceleration cycle. This enables acceleration of the higher proton intensities without significant increase in space charge effects, or beam loading of the RF cavities. The combined RF voltages are then adjusted to shorten the pulse length to allow for extraction, as in the case of single harmonic acceleration. The dual harmonic system has now been used operationally for the first time, running reliably for 36 days throughout the last ISIS user cycle of 2006. This paper reports on the hardware commissioning, beam tests and improved operational results obtained so far with dual harmonic acceleration.
Organisation CCLRC , ISIS , ISIS-ACCEL
Keywords Physics , Engineering , Accelerator RF , Dual Harmonic RF , ISIS 2007
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Language English (EN)
Type Details URI(s) Local file(s) Year
Paper In Conference Proceedings In 18th meeting of the International Collaboration on Advanced Neutron Sources (ICANS XVIII), Dongguan, China, 25-29 Apr 2007, (2007). 2007
Paper In Conference Proceedings In Particle Accelerator Conference 2007 (PAC07), Albuquerque, New Mexico, 25-28 Jun 2007, (2007). 2007