Preliminary design of a hybrid ion source for ~7Li~(3+) generation

摘要

The p(~7Li,n)~7Be reaction can be used to produce forward neutron beam based on the principle of inverse kinematics, which is useful to reduce the background of the measurement of prompt fission γ-ray emission from fast neutron induced fission of ~(235)U and ~(238)U. Based on inverse kinematics reaction, a hybrid ~7Li~(3+) ion source is going to be adopted to produce 10 eμA beam for the project of CIFNEF (Compact Intense Fast NEutron Facility) proposed by Peking University (PKU) and China Institute of Atomic Energy (CIAE). To qualify the possibility of producing multi-charged ions with a 2.45 GHz microwave source, a high B field 2.45 GHz ion source has been built at PKU. Oxygen gas was used for the source test. About 200 eμA O~(3+) and 400 eμA O~(2+) were produced with the high B field ion source. This indicates the feasibility of producing multi-charged state ions with lower frequency and high B field. Based on these results, a tandem-type hybrid ion source with the combination of a 2.45 GHz ECR ion source and a hot surface ionization source was developed for Li~(3+) ion generation at PKU. An oven will be used to produce lithium vapor and the surface ionization source converts the lithium atoms into Li~+ ions. Then Li~+ will be striped into Li~(3+) in ECR region. The configuration of magnetic field is min-B. Details will be presented in the paper.