束流位置监测器测量束流四极分量的新方法  

New methods of beam position monitors for measurement of quadrupole component

作　　者：李鹏[1] 孙葆根[1] 罗箐[1] 王晓辉[1] 卢平[1] 徐宏亮[1] 方佳[1] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029

出　　处：《强激光与粒子束》2008年第4期573-578,共6页High Power Laser and Particle Beams

基　　金：国家自然科学基金资助课题(10675118);国家985项目(173123200402002)

摘　　要：束流位置监测器可以用来进行发射度的非拦截测量,且不受束流分布的影响。对从条带BPM电极中引出的信号经过对数比检波模块处理,得出了一种对数比处理方法来提取束流的四极分量,并推导出一种同时利用差比和处理方法和对数比处理方法的混合提取方法来提取四极分量。对这些方法进行了数值模拟计算和比较,结果表明:混合提取方法效果最佳,对数比处理方法优于差比和处理方法。利用提取出的四极分量,通过多次改变四极铁的电流计算出束流的发射度。Stripline beam position monitors（BPM） can be used as a nonintercepting emittance monitor and it is independent of the beam distribution. Usually, difference over sum method is used to pick up the quadrupole component. This paper puts for-ward two new methods＇log-ratio method and combination method. The analysis and comparison of these methods are introduced. Combination method is the best, and log-ratio method is better than difference over sum method. Changing the current of quadru-pole magnets rn times （more than six times） upstream from BPM to change the transfer matrix and measuring the quadrupole component for each change, the emittance can be calculated.

关 键 词：束流位置监测器 发射度 四极分量 差比和 对数比 混合提取 非拦截测量 

分 类 号：TL506[核科学技术—核技术及应用]