Thermionic cathode gridded electron gun for RF linacs

下一代安全直线机可能会以更短的脉冲和更高的重复频率运行，以改善材料分离，单光子计数或启用后向散射x射线。然而，目前还没有这样的商业直线加速器，但是，通过利用高梯度加速器中采用的RF设计方法和技术，并利用现有的替代RF源，可以实现这样的直线加速器。实现短脉冲操作的一项关键技术将是结合网格热离子阴极电子枪来调制电子束。本课题旨在为射频直线加速器设计并建立热离子阴极栅格电子枪模型。网格电子枪设计将由斯特拉斯克莱德大学与TMD技术有限公司合作开发，TMD技术有限公司在为高功率微波放大器提供类似电子束源方面有着良好的记录。该学生将在海耶斯米德尔塞克斯的TMDs技术有限公司实习6个月，学习设计知识和对网格结构的理解，以实现高占空比操作，同时最大限度地减少波束拦截。TMD技术有限公司还将向学生提供高压电源和隔离所需的专业知识，以向电网施加电压以调制光束。此外，该学生将参与升级和运行科克罗夫特研究所现有的射频直线加速器设备，以测试最新的x射线探测器发展，并了解任何新的直线加速器的要求。

The next generation of security linacs will likely operate with shorter pulses and higher repetition frequencies to improve material separation, single photon counting or to enable backscattered X-rays to be employed. However no such commercial linac exists already, however by utilising RF design methodology and techniques employed in high gradient accelerators and utilising existing alternative RF sources such a linac could be realised. A crucial technology that will enable short pulse operation will be the incorporation of a gridded thermionic cathode electron gun to modulate the electron beam. This project aims to design and model a thermionic cathode gridded electron gun for the RF linac. The gridded electron gun design will be developed by the University of Strathclyde in collaboration with TMD Technologies Ltd who have a track record of providing similar electron beam sources for high power microwave amplifiers. The student will take a six month placement with TMDs Technologies Ltd, Hayes Middlesex to incorporate in the design knowledge and understanding of the grid structure to enable high duty cycle operation while minimising beam interception. TMD Technologies Ltd will also make available to the student expertise of high voltage power supplies and isolation needed to apply voltage to the grid to modulate the beam. In addition the student would be involved in upgrading and running the Cockcroft Institute's existing RF linac facility to test the latest X-ray detector developments and to understand the requirements of any new linacs.