论文标题
亚微米的分辨率，串联束轨迹反馈系统及其在减少单通梁中的韦克场效果的应用
A sub-micron resolution, bunch-by-bunch beam trajectory feedback system and its application to reducing wakefield effects in single-pass beamlines
论文作者
论文摘要
在日本高能量加速器研究组织的ATF2梁线上已经开发并测试了高精度内部训练射线轨道轨道轨道反馈校正系统。该系统使用在两个梁位置监测器（BPM）下测量的束的垂直位置来计算一对踢，该踢是使用两个上游踢脚仪应用于下一个束的踢，从而纠正了垂直位置和轨迹角度。使用两个电子束的列车及时分开187.6〜NS，对系统进行了优化，以便将梁偏移稳定在反馈BPM上，以大于350〜nm，从而产生局部轨迹角度校正至250〜NRAD以内。使用三个下游证人BPM验证了校正的质量，发现结果与用于传播反馈区域的光束轨迹的线性晶格模型的预测一致。该模型预测了加速器焦点处的c。〜1〜nm的校正光束抖动。在此位置使用梁尺寸监视器的测量结果表明，将梁的轨迹抖动减少4倍，还将测得的光束尺寸的增加作为梁电荷的函数降低了c。〜1.6倍。
A high-precision intra-bunch-train beam orbit feedback correction system has been developed and tested in the ATF2 beamline of the Accelerator Test Facility at the High Energy Accelerator Research Organization in Japan. The system uses the vertical position of the bunch measured at two beam position monitors (BPMs) to calculate a pair of kicks which are applied to the next bunch using two upstream kickers, thereby correcting both the vertical position and trajectory angle. Using trains of two electron bunches separated in time by 187.6~ns, the system was optimised so as to stabilize the beam offset at the feedback BPMs to better than 350~nm, yielding a local trajectory angle correction to within 250~nrad. The quality of the correction was verified using three downstream witness BPMs and the results were found to be in agreement with the predictions of a linear lattice model used to propagate the beam trajectory from the feedback region. This same model predicts a corrected beam jitter of c.~1~nm at the focal point of the accelerator. Measurements with a beam size monitor at this location demonstrate that reducing the trajectory jitter of the beam by a factor of 4 also reduces the increase in the measured beam size as a function of beam charge by a factor of c.~1.6.
