Electron Beam Acceleration Using Plasma Wakefield

等离子体韦克菲尔德加速至少使用两束电子。第一束（驱动束）在等离子体中激发等离子体波，第二束（测试束）由波的电势加速。核工程研究实验室，东京大学有两个直线加速器，每一个都可以被分配作为驱动束流发生器和测试束流发生器。2在1992年建造了传输线，它在等离子体室合并了两个直线加速器束。1993年，观测到了由驱动束流引起的测试束流的加速。特别是在等离子体密度低于束流密度的低密度等离子体中观察到了非线性反常加速。在1994年，观测到的加速是等离子体密度的函数，范围超过两个数量级。结果表明，等离子体透镜效应对驱动束团的聚焦作用使尾流场增大，最大加速度梯度约为1 MeV/m。在1995年，我们将用一列驱动束建立尾流场。

Plasma wakefield acceleration uses at least two bunches of electrons. The first bunch (drive bunch) excites plasma waves in a plasma, and the second one (test bunch) is accelerated by the potential of the wave. Nuclear Engineering Research Lab., the University of Tokyo has twin linacs, each of which can be assigned as a drive bunch generator and a test bunch generator.In 1992 transport lines were constructed which merges two linac beams at the plasma chamber. In 1993 Acceleration of the test bunches caused by the drive bunches was observed. Especially nonlinear anomalous acceleration was observed in an inderdense plasma in which the plasma density is lower than the beam density. In 1994, the acceleration was observed as a function of plasma density ranged in more than two orders of magnitude. The focusing of the drive bunches by the plasma lens effect was observed which increases the wakefields more than the prediction of the calculation based on the rigid model.The maximum acceleration gradient observed was around 1MeV/m. In 1995 we are going to build up wakefields using a train of drive bunches.