[论文解读] CEPC Conceptual Design Report: Volume 1 - Accelerator

The CEPC Study Group|arXiv (Cornell University)|Sep 2, 2018

Spacecraft and Cryogenic Technologies被引用 117

一句话总结

本论文提出圆周电子-正电子对撞机（CEPC）的加速器设计，这是一个100公里地下隧道项目，采用双环对撞机，针对希格斯、Z和W工厂运行进行优化，并附带研发与施工时间表。

ABSTRACT

The Circular Electron Positron Collider (CEPC) is a large international scientific project initiated and hosted by China. It is located in a 100-km circumference underground tunnel. The accelerator complex consists of a linear accelerator (Linac), a damping ring (DR), the Booster, the Collider and several transport lines. In the tunnel, space is reserved for a future pp collider, SPPC. The CEPC center-of-mass energy is 240 GeV, and at that collision energy will serve as a Higgs factory. The design also allows operation at 91 GeV for a Z factory and at 160 GeV for a W factory. The heart of the CEPC is a double-ring collider. It has two interaction points where are located large detectors. The Booster is in the same tunnel above the Collider. It is a synchrotron with a 10 GeV injection energy and extraction energy equal to the beam collision energy. The repetition cycle is 10 seconds. Top-up injection will be used to maintain constant luminosity. The 10 GeV Linac, injector to the Booster, built at ground level, accelerates both electrons and positrons. A 1.1 GeV damping ring reduces the positron emittance. Transport lines made of permanent magnets connect the Linac to the Booster. In addition to particle physics, the Collider can operate simultaneously as a powerful synchrotron radiation (SR) light source. It will extend the usable SR spectrum into an unprecedented energy and brightness range. Two gamma-ray beamlines are included in the design. Prior to the construction will be a five-year R&D period (2018-2022). Construction is expected to start in ~2022 and be completed in ~2030. This report is a summary of work accomplished during the past several years by hundreds of scientists and engineers at home and abroad. The current volume, Volume I, is on the accelerators. A separate volume, Volume II, will be on physics and the detectors.

研究动机与目标

• 推动一个大型国际项目，在中国建设100公里 CEPC 加速器综合体。
• 描述包括线加速器(Linac)、阻尼环、增强器、对撞机，以及未来SPPC隧道容纳空间在内的加速器布局。
• 为希格斯工厂在240 GeV运行以及Z、W工厂的更低能量模式定义能量和光度目标。
• 解释建设与运营计划，包括持续注入（top-up injection）和同步辐射光源能力。

提出的方法

• 描述加速器组件的序列及其功能（线加速器 Linac、阻尼环、增强器 Booster、对撞机、传输线）。
• 解释在传输线中使用永久磁铁，以及用于顶-up 注入的10 Hz–10 s 重复周期。
• 概述作为同步辐射光源的双重用途潜力，具伽马射线光束线。
• 提供一个五年研发期（2018–2022）以及预计的建设启动时间（约2022）和完成时间（约2030）。

实验结果

研究问题

• RQ1 CEPC 的拟议加速器布局及其组成部分是什么？
• RQ2 希格斯、Z和W工厂模式的能量工作点和光度策略是什么？
• RQ3 CEPC 如何容纳顶-up 注入并提供 SR-同步辐射光源功能？
• RQ4 从研发到建设与调试的计划发展时间线是什么？
• RQ5 未来 SPPC 的隧道空间将如何集成到 CEPC 设计中？

主要发现

• CEPC 被设想为一个双环对撞机，具有用于大型探测器的两个交互点。
• 质心能量目标为希格斯工厂在240 GeV运行；Z工厂为91 GeV；W工厂为160 GeV。
• 一个10 GeV 注入线性加速器（Linac）供给 Booster，经 Booster 将粒子送往对撞机，具有10秒重复周期和顶-up 注入。
• 一个1.1 GeV 阻尼环在注入前降低正电子发射度。
• 设计包括使用永久磁铁的传输线，并为未来的质子-质子对撞机 SPPC 保留隧道空间。
• 该对撞机既可作为高能物理设备，也可作为强大的同步辐射光源，包含两条伽马射线光束线。