Proton beam intensity and proton fraction measurement of the 2.45 GHz ECR ion source

Abstract

In this paper we report results of experimental studies of the dependence of the proton beam intensity and proton fraction of the 2.45 GHz electron cyclotron resonance (ECR) ion source on the operational parameters such as extraction voltage, microwave window, impedance matching, gas flow, microwave power, pipeline gas pressure, plasma chamber size, and magnetic field. The DC hydrogen ion beams are measured and analyzed on the bench of ion source and pre-analysis system of the Lanzhou university high intensity neutron generator ZF400. Our results show that a higher proton beam intensity and fraction can be obtained with a microwave window made up of 2 mm AlN. The proton beam intensity and fraction strongly depend on the three-stub tuner that controls the impedance matching between microwave and plasma. We also observe notable beam loss under the lower vacuum pressure condition.