为了提高射频四极场加速器(RFQ)的束流传输效率, 需要对纵向分布不均匀的极间电压进行补偿, 并且准确测量束流实验中极间电压的绝对数值。考虑到极间电压分布不均匀是由于分布电容和端部效应造成的, 而采用调谐块可以调节分布电感, 通过电磁场数值模拟研究了调谐块对极间电压分布的影响, 最终极间电压的平整度被调整到优于95%。在束流实验中, 通过测量轫致辐射谱测定了极间电压的数值, 通过束流动力学模拟研究了多能峰产生的原因, 并最终标定了70 kV极间电压对应的输入功率值284 kW。

In order to improve beam transmission efficiency for a four-rod radio frequency quadrupole (RFQ) accelerator, inter-electrode voltage distribution must be tuned and its accurate value need to be measured. Effect of tuning plates on inter-electrode voltage distribution was studied by electromagnetic numerical simulation, as the unflatness of the voltage distribution was caused by unevenly distributed capacitance and tuning plates could change the distributed inductance. The final inter-electrode voltage distribution was tuned to be better than 95%. In beam commissioning, inter-electrode voltage was determined by measuring the energy spectrum of X-ray and multiple energy peaks were studied by beam dynamics simulation. Input power was calibrated with beam commissioning results that 284 kW was needed in order to get 70 kV inter-electrode voltage.