AWAKE - additional equipment

支持帝国理工WP 4工作的额外设备：等离子体放电源。目标概述如下：2.4 WP 4：放电等离子体源放电等离子体单元与金属蒸汽和螺旋源一起，是AWAKE的技术选项之一，如设计报告所述。放电单元相对于其他两个具有显著的优点，即，它可扩展到长距离（即，数十米及更远），而金属蒸汽单元的情况不是这样，并且尽管螺旋波同样可扩展，但由于产生螺旋波所需的大量RF，这是比放电源昂贵得多的选择。放电单元的简单玻璃管结构也应该使其更适合于可以利用放电单元的开放结构的诊断设备（例如WP 2）。这项工作是由帝国领导，与纳尔逊洛佩斯清醒的任务负责人，在合作与里斯本。在目前的赠款期间，已经建立了原型，具有10 mm直径1.5 m长的电池，其基于在2 kV下提供约300 A的1.6微秒脉冲放电以约0.3 Hz运行。该电源是基于帝国内部制造的原型。使用干涉测量的密度均匀性的测量正在进行中，完成后应证明这些放电的可行性，在配置接近所需的清醒。明年要解决的关键问题是：* 获得玻璃管中的气压稳定性;* 获得所需的等离子体均匀性;* 测量所需的等离子体密度;* 确保高压设置的可靠性;* 符合CERN标准;* 开发更长（最长10米）的原型。

Additional equipment to support Imperial's work on WP4: Plasma Discharge Source. A summary of the objectives are given below:2.4 WP4 : Discharge plasma sourceAlong with the metal vapour and helicon sources, the discharge plasma cell is one of the tech- nology options for AWAKEas described in the Design Report. The discharge cell has significant advantages over the other two, viz. it is scalable tolong distances (i.e. tens of metres and beyond) which is not the case for the metal vapour cell, and although the helicon issimilarly scalable, this is a far more expensive option than the discharge source due to the large amounts of RF needed togenerate the helicon waves. The simple, glass-tube structure of the discharge cell should also make it more amenable todiagnostic devices (e.g. WP2) which can utilise the open structure of the discharge cell. The work is led by Imperial, withNelson Lopes the AWAKE task leader, in collaboration with Lisbon. During the current grant, prototypes have been built,with a 10mm diameter 1.5m long cell operated at ~0.3Hz based on a 1.6 microsecond pulsed electrical discharge thatprovides ~300 A at 2 kV. The power supply is based on a prototype built in-house at Imperial. Measurements of the densityuniformity using interferometry are now underway which after completion should demonstrate the feasibility of thesedischarges in a configuration close to the that needed for AWAKE. Longer cells are also in preparation.The key issues to be worked on during the next year are:* Obtain gas pressure stability in the glass tube;* Obtain the required plasma uniformity;* Measure the required plasma density;* Ensure HV setup reliability;* Comply with CERN standards;* Development of longer (up to 10 m) prototypes.