以11 MV回旋加速器潘宁离子源作为研究对象，通过调节磁场强度研究了磁场对工作在弧放电模式下的潘宁离子源的影响规律，深入分析了该放电模式下的放电自持机制、磁场引起的阻抗变化规律、异常发光现象。实验在6 mL/min氢气流量下，保持离子源弧流不变，调节磁场强度，记录磁场强度对弧压的影响。实验结果表明: 二次电子发射机制与热电子发射机制在潘宁源自持放电过程中发挥了同样重要的作用; 在强磁场情况下离子源阻抗受到磁场变化影响不大，在磁场小于0.15 T时磁场的作用才变得明显; 当磁场减弱至等离子体进入阻抗增长区后，存在一段等离子体剧烈放电、光强突然增加的区域。在实验的基础上，得到了设计潘宁源的启发，并分析了磁场对等离子体电导率影响的微观物理机制，这些有助于研制或使用工作在弧放电模式下的潘宁离子源。

In this article the Penning-type negative hydrogen ion source of 11 MeV compact cyclotron is studied. This ion source works in arc-mode. By changing the magnetic field strength, the impact of the magnetic field on ion source’s work situation is analyzed. These issues are analyzed in the article: the mechanical properties of sustained discharge in the ion source, the impedance change of the ion source when the magnetic field varies, abnormal glow observed at the extraction slit. In this experiment, when hydrogen flow is stabled at 6 mL/min, changing the magnetic strength will influence Penning discharge. The result indicates that at strong magnetic field condition, the plasma conductivity almost does not change; but when the magnetic strength gets weak (less than 0.15 T), the plasma resistivity will increase rapidly, and there is a fierce discharge/glow of plasma brightening rapidly in this condition. Some inspiration in the design of PIG source are got from this experiment,and we are trying to analyze the probable microcosmic physics mechanism of this phenomenon in the discussion.