Development of Multibunch Beam Energy Compensation System

多束束能量补偿方法的开发是在高能加速器研究机构的加速器试验台进行的，是直线对撞机开发的关键技术之一。中频调相法是最可行的多束能量补偿方法，因此对该方法的应用进行了开发研究。由于结构间的能量补偿，可以将色散效应和色度效应引起的发射度增长降低到最小。在本研究的第一年1997年，完成了将两个速调管输出功率组合在一起的大功率中频合成器的设计和制作，并在具有重排波导系统的ATF速调管系统上进行了高功率中频合成器的测试，以实现两个速调管输出功率的组合。对系统进行了高达50MW速调管输出电平的处理，验证了系统在高功率电平下的相幅调制性能。第二年1998年，在ATE直线实验室进行了梁试验。任意波形发生器安装在调相控制脉冲中。在ATE直线电机中，在直线电机中间安装磁体结构，进行多束能量测量。为了优化中频振幅变化斜率，测量了每个速调管在低能级中频下的相位调制速度，通过使用这些仪器和精心调整，我们可以成功地补偿ATE多束（20束，2.8ns间距）中的光束能量差。实验证明了相幅调制方法适用于多束能量补偿。这两年的研究成果使相幅调制方法能够有效地补偿多束能量差，这将是未来线性对撞机的一个问题。还可以了解实际应用中需要开发的if组件。

The development of multibunch beam energy compensation method is held in ATF(Accelerator Test Facility) of the high energy accelerator research organization as an one of key technology of linear collider developments. The if phase modulation method for multibunch energy compensation is the most feasible method, so the development research to apply this method was proceeded. It is possible to reduce the emittance growth arising from the effect of dispersion and chromatic effect to its minimum, because of structure by structure of energy compensation.In 1997, the first year of this reseach, the design and fabrication of the high power if combiner to combine the output power of two klystrons were done, The high power test of the if combiner was held at ATF klystron system with rearranged wave guide system in order to combine two klystrons output. The system was processed upto 50MW klystron output level and proved the performance of phase-to-amplitude modulation at high power level.In 1998, the second year, the beam test was held at ATE linac. The arbitoraly waveform generator is installed in the phase moduration control pulse. In ATE linac, the sichane magnet configuration is install in the middle of linac in oider to make multibunch energy measurement. In order to optimize the if amplitude variation slope, the phase moduration speed at low-level if for each klystron was surveyed, By using these instruments and careful adjustment, we could succeed to compensate the beam energy difference in ATE multibunch (20 bunch, 2.8ns spacing). This experiment proved that the phase-to amplitude moduration method is applicable for the multibunch energy compensation.This two years research makes it possible that the phase-to-amplitude moduration method is effective to compensate multibunch energy difference which will be a problem in future linear collider. Also we could know the if component which is need to develop for real application.