R&D in preparation for an upgrade of CMS for the Super-LHC

大型强子对撞机将被升级，以将亮度提高一个数量级，达到10^35 cm-2.s-1。升级的日期尚未确定，但预计将在LHC开始运行后10年左右。机器参数尚未冻结，但时钟速度预计为20 MHz，而不是目前的40 MHz。其动机是扩大LHC的物理范围，并以更高的精度研究LHC预期将取得的发现，因为在最大光度数年后，统计增益随着时间或积分光度逐渐下降。CMS升级的主要部分将是建造一个新的跟踪探测器，在二次粒子注量大大增加的条件下以类似的性能运行，每次束流交叉约为20倍。随着辐射损伤的增加，复制并向探测器提供电力存在重大技术挑战。如果要达到或超过本跟踪器的整体性能，则要实现的重要目标是较低的功率操作和减少的材料预算。还有一个额外的新挑战是将第一级触发速率保持在100 kHz以下。实现这一点的主要创新将是在第一级硬件触发决策中包括来自跟踪器的数据，这是非常新颖且极具挑战性的。仿真研究是设计新的跟踪器和实现触发目标的重要组成部分。联合王国CMS计划利用其现有的专门知识，为模拟、读出和触发活动作出贡献。它希望在未来的CMS中保持突出的地位，我们在探测器建设，计算和物理分析方面拥有完善的重要科学管理角色。

The LHC machine will be upgraded to increase the luminosity by an order of magnitude to 10^35 cm-2.s-1. The date for the upgrade is not yet defined but is expected to be about 10 years after LHC starts operating. The machine parameters are not yet frozen but the clock speed is expected to be 20MHz instead of the current 40MHz. The motivation is to extend the physics reach of the LHC and to study with greater precision the discoveries expected to be made at LHC since, after several years at maximum luminosity, the statistical gains gradually decline with time, or integrated luminosity. The major part of the CMS upgrade will be to construct a new tracking detector to operate with similar performance in conditions of greatly increased secondary particle fluences, by a factor of about 20 in each bunch crossing. There are major technical challenges to copy with increased radiation damage and deliver power to the detector. If the overall performance of the present tracker is to be equalled or exceeded, lower power operation and a reduced material budget are important objectives to achieve. There is an additional new challenge to maintain the first level trigger rate at below 100kHz. The main innovation to make this possible will be to include data from the tracker in the first level hardware trigger decision, which is very novel and extremely challenging. Simulation studies form an important element of designing a new tracker and achieving the triggering objective. UK CMS plans to build on its existing expertise to contribute to the simulations, readout and triggering activities. It expects to maintain a prominent position in a future CMS where we hold well established important scientific management roles, in detector construction, computing, and physics analysis.