天鹅绒阴极脉冲放气及重复频率运行真空特性

为获得天鹅绒阴极加电运行时的放气信息,在加速器Torch-02(电压约300 kV、脉宽约6 ns、电阻约100Ω、频率1~300 Hz)上开展了单次及重复频率下的真空兼容性实验研究。对于发射面积为28 cm2、阴阳极间距50 mm、有效抽速62 L/s、容积为4.6 L的真空二极管-天鹅绒阴极系统,根据不同电流发射密度时的气压历史曲线,确定了单位面积上天鹅绒表面中性气体释放数目与脉冲能量的关系。通过实时记录不同频率下的气压演化,在本底气压约5×10-3Pa、单脉冲能量约6 J条件下,得到了平衡压强与重复频率的变化关系:10~100 Hz时,平衡压强与重复频率近似呈线性递增;超过100 Hz时,真空恶化明显,气压随频率呈超线性增长,300 Hz时平衡压强已升至Pa量级。最后,针对重复频率运行时的放气特点,讨论了一种"分布式"抽气思想以改善系统有效抽速。

Outgassing characteristics of velvet cathode under single and repetition rate pulse operation

Outgassing characteristics of a polymer velvet cathode under single shot and repetition rate(rep-rate) operation were experimentally investigated on a pulser,Torch-02,which has an about 300 kV,adout 6 ns and 1 to 300 Hz rep-rate output.For a 10 L vacuum diode-velvet cathode system with an emission area of 28 cm2,an A-K gap of 50 mm and an effective pumping speed of 62 L/s,the pulse desorption profiles with different emitting current densities were obtained.According to the pressure histories,the dependence ...