Emittance Measurements and Operation Optimization for ECR Ion Sources

Abstract

Electron Cyclotron Resonance (ECR) ion sources supply a broad range of ions for post acceleration in cyclotrons. Here, an effort to improve the beam transfer from RIKEN's 18 GHz superconducting ECR ion source (SC ECRIS) to the Low Energy Beam Transfer (LEBT) line and an optimization of the performance of the ion source is presented. Simulation studies have shown that less than 20% of the beam is currently transferred. The first goal is to measure the transverse beam emittance in real time. The emittance monitor designed and fabricated for this purpose utilizes a pepper pot plate followed by a transparent scintillator and a CMOS camera for image capture. The second goal is to investigate on dependencies between beam emittance and various operating parameters. To this extent, modifications of the ion source took place, as well as a measurement of the magnetic field inside the ion source. In this contribution the design details of the instrument and a description of the algorithm are presented as well as a typical emittance measurement.