Proposal for continuation of the Front End Test Stand

质子是构成物质的一种亚原子粒子，通过一台名为质子加速器的机器可以获得大量能量。这种高能质子可用于广泛的应用，从生产用于治疗疾病的放射性同位素，到研究有利于工业和科学的物质结构。任何质子加速器复合体的第一步都是所谓的质子驱动器。正在英国卢瑟福·阿普尔顿实验室建造的前端测试台(FETS)是一个项目，旨在创造一种新的最先进的质子驱动器，以便为未来的应用提供更强、更高能量的质子加速器。FETS产生一束带负电的氢离子，这些离子被切成更小的束。为了更安全、更容易地加速通过从氢离子束中移除电子而获得的质子，这种切割是必要的。FETS的合作包括一支由来自英国的科学家和工程师组成的专门团队，并促进了与CERN、FNAL、ESS和CNS等领先的国际加速器研究所的合作。在这项建议中，我们寻求及时完成FETS的建设。氢离子源和初始束流聚焦组件已经建成并成功投入使用。剩下的工作是安装、测试和调试加速结构和斩波系统，并评估整个试验台的性能。在该项目成功完成后，FETS可以用作质子驱动器，用于工业、医学和科学中广泛应用的质子加速器系统的进一步开发。

Protons, subatomic particles that are one of the building blocks of matter, can be given large amounts of energy by passing through a machine called a proton accelerator. Such high energy protons can be used in a wide variety of applications, from the production of radioisotopes for the treatment of disease, to the investigation of the structure of matter that benefits both industry and science. The first step in any proton accelerator complex is the so-called proton driver. The Front End Test Stand (FETS), being built at the Rutherford Appleton Laboratory (RAL) in the UK, is a project to create a new state-of-the-art proton driver that will be needed in order to provide proton accelerators with more intense, higher energy beams for future applications. The FETS produces a beam of negatively-charged hydrogen ions that is chopped up into smaller bunches. This chopping is needed in order to make it safer and easier to accelerate the protons that are obtained by removing the electrons from the hydrogen ion beam. The FETS collaboration involves a dedicated team of scientists and engineers from the UK, and has stimulated collaborations with leading international accelerator institutes such as CERN, FNAL, ESS and CNS.In this proposal, we seek to complete the construction of the FETS in a timely manner. The hydrogen ion source and initial beam focusing components have already been built and successfully commissioned. The remaining work is to install, test and commission the accelerating structures and chopper systems, and to evaluate the performace of the complete test stand. Upon successful completion of this project, the FETS can be used as a proton driver for further developments in proton accelerator systems for a wide range of applications in industry, medicine and science.