2.45GHz强流脉冲质子源

2.45 GHz Intense Pulsed Proton Source

介绍了一台用于强流质子直线加速器注入的2.45GHz电子回旋共振强流脉冲质子源。采用2.45GHz的微波馈入实现以氢气为载气的氢等离子体,在三电极引出系统下获得能量50keV,50mA的强流脉冲离子束。其中三电极分别为等离子体电极、抑制电极及地电极。用CST仿真软件和PBGUNS分别模拟计算了匹配波导能量的传输效率与引出束流传输轨迹,得出信号输入端口反射系数S11约为0.119,整个匹配波导内正向传输系数S21为0.993,引出束流在Z=26cm处,束流包络约为2cm。研究了离子源轴向磁场变化对引出束流强度的影响,结果得出,当螺线管电流从0A增加至50A时,引出混合束流强度从20mA上升至50mA。

A 2.45 GHz high current pulsed proton source for proton linear accelerator injector was introduced.Hydrogen plasma was obtained using a microwave feeding at the frequency of 2.45 GHz.A 50 keV,50 mA pulsed beam was extracted by a 3-electrode system consisting of the plasma electrode,suppression electrode and grounded electrode.The characteristics of extracted beam and impedance matching of the transitional waveguide were studied by by CST and PBGUNS codes.The effect of the axial magnetic field distribution on extraction beam was studied by 2D-Poission code.The transmission and reflection coefficients were 0.993 and 0.119,respectively,when the frequency varied from 1.8 to 3.2 GHz.The results show that the total ion current reaches from 0 to 50 A,and the current of the extraction beam reaches from 20 to 50 mA.