• D. Fernandez-Cañoto, I. Bustinduy, D. de Cos
  ESS Bilbao, Bilbao
• F.J. Bermejo
  Bilbao, Faculty of Science and Technology, Bilbao
• J. Feuchtwanger, J.L. Munoz
  ESS-Bilbao, Zamudio

The goal of extracting high proton currents from the ECR source of the Bilbao Accelerator has required comprehensive and interactive studies by using systematic beam dynamics simulations to derive acceptable geometric parameters for the projected electrode extraction system. Two tetrode designs were mainly analyzed; the first is based on a Pierce geometry; and the second on a spherically convergent extraction system. Both designs consist of a plasma electrode at 75kV, and then, a puller system formed by a grounded electrode separated from the plasma chamber to a certain extraction-gap distance, an electron repeller electrode fed at -3kV, and finally a grounded electrode. Geometric parameters such as the distances between electrodes, the different electrode apertures, the plasma electrode angle related to the Pierce layout, and also, the plasma and extraction electrode radial shapes related to the spherical extractor design were optimized for a 70mA proton beam.