New approach toward optimized resonant slow-extraction

A resonant slow-extraction method from synchrotron rings has been successfully developed in order to deliver a beam for a period of over several seconds. In the resonant slow-extraction method, an optimization of the parameters is necessary in order to keep the beam size and position constant during the extraction for sufficient use of the extracted beam. For this purpose, a simple method to measure the outgoing separatrix was proposed and verified at the HIMAC synchrotron. In this method, two tantalum rods each with diameter of 1 mm are used as internal probes located near the extraction channel. By observing the extracted beam under the rods inserted into the ring, the outgoing separatrix can be measured. This technique will significantly contribute to the operation of a synchrotron employing resonant slow-extraction.