摘要
High current hydrogen molecular ion beam is obtained with a specially designed stainless steel liner permanent magnet2.45-GHz electron–cyclotron resonance（ECR） ion source（PMECR II） at Peking University（PKU）. To further understand the physics of the hydrogen generation process inside a plasma chamber, theoretical and experimental investigations on the liner material of the plasma chamber in different running conditions are carried out. Several kinds of materials, stainless steel（SS）, tantalum（Ta）, quartz, and aluminum（Al） are selected in our study. Experimental results show that stainless steel and tantalum are much better than others in H~＋_2 generation. During the experiment, an increasing trend in H~＋_2 fraction is observed with stainless steel liner after O_2 discharge inside the ion source. Surface analyses show that the roughness change on the surface after O_2 discharge may be responsible for this phenomenon. After these studies, the pure current of H~＋_2 ions can reach 42.3 mA with a fraction of 52.9%. More details are presented in this paper.
High current hydrogen molecular ion beam is obtained with a specially designed stainless steel liner permanent magnet2.45-GHz electron–cyclotron resonance（ECR） ion source（PMECR II） at Peking University（PKU）. To further understand the physics of the hydrogen generation process inside a plasma chamber, theoretical and experimental investigations on the liner material of the plasma chamber in different running conditions are carried out. Several kinds of materials, stainless steel（SS）, tantalum（Ta）, quartz, and aluminum（Al） are selected in our study. Experimental results show that stainless steel and tantalum are much better than others in H~＋_2 generation. During the experiment, an increasing trend in H~＋_2 fraction is observed with stainless steel liner after O_2 discharge inside the ion source. Surface analyses show that the roughness change on the surface after O_2 discharge may be responsible for this phenomenon. After these studies, the pure current of H~＋_2 ions can reach 42.3 mA with a fraction of 52.9%. More details are presented in this paper.
基金
supported by the National Natural Science Foundation of China(Grant Nos.11175009 and 11575013)
