Hybrid Quadrupole Lens for the Focusing Channel of the DARIA Complex

Abstract

The results of synthesis and electromagnetic calculation of a hybrid quadrupole lens for a proton linear accelerator of a compact neutron source DARIA are presented. The lens includes a permanent magnet quadrupole with a fixed magnetic field gradient and an auxiliary electromagnetic quadrupole excited by a pulsed current. The permanent magnet quadrupole is made of radiation-resistant rare-earth magnet, and the electromagnetic quadrupole is designed to compensate for permanent magnet magnetization losses resulting from radiation degradation as neutron fluence accumulates during accelerator operation. A hybrid quadrupole lens can be applied for fast adjustment of the focusing channel when accelerating ion beams with different ion mass-to-charge ratios.