ECR Ion Sources for H− Ion Production: First Results and Prospects

Abstract

ECR Ion Sources are well known for their efficient production of Highly Charged Ions [1], and also for the production of intense proton beams [2]. Recently European laboratories have decided to join their efforts to develop and improve various plasma techniques for the production of intense beams of H−, for a future application to the European Spallation Source, and possibly for other high power accelerators. Because of its great experience and skill in ECR plasmas and ion sources, CEA has decided to develop ECR ion sources for negative ion production. At first glance, this seems to be a real challenge, as negative ion production requires a very low electron temperature, incompatible with ECR heating. We will show that this contradiction can be solved. In this article we briefly summarize the present status of Negative Ion Sources (NIS). Then we describe ECR Ion Sources and how they can be of great interest for H− production. Although this domain is still rather unexplored, some work has already been performed in the field of negative ion production with ECR plasmas. That work will be shortly summarized. Eventually promising preliminary results, obtained at CEA Saclay at 2.45 GHz, will be shown.