微波加热模式对ECR离子源等离子体以及高电荷态离子产生影响的研究

By studying several fundamental issues concerning the ECRH (Electron Cyclotron Resonance Heating)inside a so called 3rd generation ECR ion source, a systematic understanding of the mechnism of high power high frequency microwave coupling and heating to the ECR plasma is desired. With the study, it is possible to improve the microwave coupling and ECRH efficiency, especially with respect to the production of highly charged ions. Eventually, through the researh, the ion source performance is expected to be improved to some extent, in terms of both the plasma stability and extracted ion beam quality. Meanwhile, with the project study, we are aiming to find a new ECRH mode that is more suitable for the production of high charge state ions inside one 3rd generation high performance ECR ion source,which is essential for the prototype of the next generation high performance ECR ion source. This goal needs us to find the answers to the key issues such as high power mm wave length microwave transmission, coupling and ECRH mode which are suitable for the ion source's high performance output.

本项目拟通过对微波加热模式的研究，对现有的第三代高性能电子回旋共振离子源的ECR加热模式进行系统分析与改进研究，旨在对微波加热模式与高离化态ECR等离子体的产生以及不同微波模式馈入时ECR等离子体的特性进行更为深入的了解，从而提高微波加热效率，提高等离子体的稳定性，进而提高离子源装置的性能，提高离子束流的品质。同时，通过对新工作模式的研究，探索解决下一代高性能电子回旋共振离子源装置关于微波加热技术中存在的几个关键问题，如高功率毫米微波的传输、馈入、耦合加热等。

本项目针对目前高性能第三代离子源发展中的关键问题之一，即高功率24~28 GHz微波馈入、耦合加热ECR等离子体产生高电荷态离子的效率问题，结合近物所的两台高性能全超导ECR离子源SECRAL与SECRAL-II开展了一系列实验探索研究与分析，并在此基础上给出了第四代装置的微波传输、馈入以及耦合加热ECR等离子体的解决方案。本项目研究研究的突出成果是①通过微波耦合效率的提高，将高电荷态离子产额提高了20%~50%，同时创造了一系列国际流强新纪录，②首次实现45 GHz微波加热ECR等离子体，并产生高电荷态离子束，③发现多频（>2）微波加热模式对ECR等离子体稳定性的影响与新的规律，这些发现与成果对高电荷态ECR离子源的发展将有深刻的影响。