Beam Formation Studies on the CERN IS03b H Source

Abstract An H - ion source is being operated at the new 160 MeV linear injector (Linac4) of CERN accelerator complex. The source’s plasma Radio Frequency Inductively Coupled Plasma type (RF-ICP), without magnetic cusp and runs with Cs-loss compensation [1]. Vertical downward oriented filter- electron dump-dipolar fields expand over chamber, beam-formation, beam-extraction dump regions generate horizontal asymmetry beam angular deflection partially compensated by mechanical alignment front-end. generated via volume caesiated surface modes, latter inducing a radial characterized an increased current density close to electrode [2]. Asymmetries affecting meniscus shape, or its have be simulated 3D Particle In Cell Monte Carlo (PIC-MC) solvers, such as Orsay Negative Ion eXtraction code (ONIX) [3]. Validation these simulations require dedicated measurements. This contribution describes experimental methods newly implemented CERN’s test stand initial results for Optical Beam Emission Spectroscopy (OES, BES), emittance profile later stage, gathered data sets can compared parameters extracted from PIC-MC simulations, once coupled Simulation (IBSimu) [4] transport code. parameter space includes RF-power, neutrals, position RF coil extraction field. Beams , D protons were produced; examples measured are presented in this contribution.