Production of intense Ca-48 ion beam at the U-400 cyclotron

Production of the intense accelerated Ca-48 ion beam is the key problem in the experiments on synthesizing of new heavy nuclei. For this purpose an ax ial injection system with the electron cyclotron resonance (ECR)-4M ion sou rce was created for the U400 cyclotron. The task was to achieve an accelera ted beam with an intensity of 0.5 p mu A of Ca-48(5+) at the Ca-48 consumpt ion of similar to 0.5 mg/h. To solve this problem, a new method for the sol id material feed into the ECR source was developed. The combination of a mi cro oven with a hot tantalum sheet inside the discharge chamber allowed the production of intense beams of ions of metals with relatively low melting point. The present article describes the method, technique, and experimenta l results on the production of Ca-48 ion beam at the U-400 cyclotron from t he ECR-4M ion source. The analysis of the working substance balance in the ion source including the ion beam extraction and material regeneration is p erformed. The analysis based on the experimental data has shown that the ef ficiency of Ca atom transformation into ion beam is close to that obtained for the gases such as Ar, and the intensity of Ca-48(5+) constitutes about 20% of the extracted ion beam. (C) 2000 American Institute of Physics. [S00 34-6748(00)59602-6].