A development of automatic tuning for high energy beamlines at HIMAC

Abstract

A beamline tuning system based on automatic procedure for steering a beam with observing the beam position has been under development for the transport of high energy beams at HIMAC. A daily beamline tuning for radiotherapy and for most biological experiments is carried out to precisely transport the beam to beam delivery devices. This system replays the daily procedure automatically. A beam is steered using steering magnets in accordance with the deviation of beam positions from intended beam positions. How much the beam positions shift due to adjusting a steering magnet is determined by the beam optics design. Therefore, if correlation between deflection angles at the steering magnets and variations in the beam position measured by wire-grids are known, the deflection angles can be calculated by solving linear simultaneous equations. The correlation was measured and compared with those calculated. Most of them are in good agreement. At present, the beamline tuning for delivering beams to the biological experiment room is finished in about 10 minutes automatically.

Present status of HIMAC at NIRS

“…To make this period short further, improvements on the control software's of accelerator [6] and monitors in the irradiation system are planed. One of these improvements is an automatic tuning system of the beam transport line [7]. Another improvement is the range check in the irradiation system when the beam energy is switched.…”