MEASUREMENTS OF A REDUCED ENERGY SPREAD OF A RECIRCULATING LINAC BY NON-ISOCHRONOUS BEAM DYNAMICS*
MEASUREMENTS OF A REDUCED ENERGY SPREAD OF A RECIRCULATING LINAC BY NON-ISOCHRONOUS BEAM DYNAMICS*
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通过非等时光束动力学测量循环直线加速器的降低能量扩散*
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
N. Pietralla
中科院分区：
文献类型：
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作者：
F. Hug;C. Burandt;M. Konrad;N. Pietralla
德国达姆施塔特大学的超导直线加速器S-达利纳克是一台具有两次再循环的循环直线加速器，它为核物理中的小动量转移测量提供束流。对于这些实验，能量散布需要优于10-4(RMS)。目前，直线加速器段的加速是在加速场的波峰上进行的。再循环路径是消色差和等时运行的。在这种再循环方案中，理想情况下产生的束流的能量散布由电子束长度决定。考虑到射频系统的稳定性，能量扩散急剧增加到10-3(均方根)以上。我们将提出一种新的非等时再循环方案，以帮助抵消这些来自射频抖动的误差。该方案在回流路径中使用纵向弥散，并在相对于最大值的某一阶段上加速偏离峰顶。我们将介绍新系统的调试结果，包括测量再循环弧中的纵向色散以及使用电子能谱仪测量由此产生的能量扩散。
The Superconducting Linear Accelerator S-DALINAC at the University of Darmstadt (Germany) is a recirculating linac with two recirculations providing beams for measurements in nuclear physics at small momentum transfers. For these experiments an energy spread of better than 10 -4 (rms) is needed. Currently acceleration in the linac section is done on crest of the accelerating field. The recirculation path is operated achromatic and isochronous. In this recirculation scheme the energy spread of the resulting beam in the ideal case is determined by the electron bunch length. Taking into account the stability of the RF system the energy spread increases drastically to more than 10 -3 (rms). We will present a new non-isochronous recirculation scheme which helps cancelling out these errors coming from the RF-jitters. This scheme uses longitudinal dispersion in the recirculation paths and an acceleration off-crest on a certain phase with respect to the maximum. We will present results of the commissioning of the new system including measurements of the longitudinal dispersion in the recirculation arcs as well as measurements of the resulting energy spread using an electron spectrometer.