Measurement of small electron-beam spots

Measurements of transverse beam size are tremendously important to the performance of e(+)e(-) linear colliders. In this paper we review the traditional technologies used to make such measurements, such as profile monitors and wire scanners, and their limitations. We introduce a new technique for electron beam-size measurement: Compton-scattered laser light, which may be used as an unbreakable "wire" or in the form of an interferometer beam-size monitor (BSM), We describe the use of such an interferometer BSM, noting both the general issues related to its design and operation and the specific experiences with such an interferometer at the Final Focus Test Beam at SLAG, We conclude by considering the ultimate limitations of the laser-interferometer BSM.

横向束流尺寸的测量对于正负电子直线对撞机的性能极其重要。在本文中，我们回顾了用于此类测量的传统技术，例如剖面监测器和丝扫描器，以及它们的局限性。我们介绍一种用于电子束流尺寸测量的新技术：康普顿散射激光，它可以用作一种不会断裂的“丝”，或者以干涉仪束流尺寸监测器（BSM）的形式使用。我们描述了这种干涉仪BSM的使用，同时指出了与其设计和操作相关的一般性问题，以及在斯坦福直线加速器中心（SLAC）的最终聚焦测试束流中使用这种干涉仪的具体经验。最后我们考虑了激光干涉仪BSM的最终局限性。