双频加热的LECR3离子源设计及初步的调试

研制成功了一台新的ECR（Electron Cyclotron Resonance）离子源LECR3（Lanzhou ECR No.3）。该离子源能为原子核物理与表面物理研究提供高电荷态离子束流，LECR3的设计主要基于IMP（Institute of Modern Physics）的14.5GHz ECR离子源（Lanzhou ECR No.2），但采用了双频加热、波导直接馈入微波功率及铝制等离子体弧腔等新技术和新方法。另外，LECR3的弧腔容积比LECR2的大，增加可注入的微波功率，可有效地增加引出的高电荷态离子束流的强度。虽然增大了弧腔的内么，但仍然保持径向六极磁铁在弧腔内壁上产生最大磁场强度与LECR2的同样大小。

The design of the double-RF heating LECR3 ion source and its preliminary results

A new ECR (Electron Cyclotron Resonance) ion source with double RF heating was constructed in Lanzhou this year. The main purpose of this source is to provide highly charged ion beams for atomic physics and surface physics research. The design of this ion source is based on the IMP 14.5GHz ECR ion source (LECR2-Lanzhou Electron Cyclotron Resonance ion source No.2) with double RF heating by inserting waveguide directly and aluminium chamber. Furthermore, the volume of the plasma chamber is larger than that of LECR2 so as to increase the RF power and improve beam intensity for highly charged ions. But the hexapole field on the chamber wall is kept the same value in order to compare with the performance of LECR2. After only four days conditioning the first test results were obtained. The final result of this ion source is expected better than LECR2's.