Uniform irradiation with a combination of an octupole magnet and a scanning magnet in the KOMAC Beam lines

Abstract

One of the important requirements in user beam lines of the KOMAC (Korea Multi-purpose Accelerator Complex) 100-MeV linac facility is the ±10% uniformity of the particle distribution over the irradiation area. For a long beam line, we found that it can be achieved by using the usual octupole method. However, the lengths of other beam lines are too short to generate uniform irradiation on target by using two octupole magnets. In this work, we studied the combination of an octupole magnet, which makes uniform particle distribution in one direction, and a scanning magnet, which shifts the beam center in the perpendicular direction and makes uniform irradiation by adding several pulses. This report summarizes the condition of uniform beam irradiation and the characteristics of beam on target in the KOMAC 100-MeV beam line.