Effect of solenoidal magnetic field on ion charge state distribution in laser ion source

Abstract

Applying a solenoidal magnetic field to a laser produced plasma is a method to increase the ion beam current supplied from a laser ion source to applications. The purpose of this study is to investigate the effects of the solenoid magnetic field on the charge state distribution of the ion beam extracted from the laser ion source. A plasma generated by a Nd: YAG laser was injected into the solenoid lens with a length of 25 mm. The current waveforms of ion beams extracted from the laser produced plasmas were measured as a function of solenoidal field strength. In addition, the variation of beam current waveforms for each charge state ion was investigated. The results indicated that the charge state distribution in the plasma was kept after focusing by the solenoid magnetic field.