The CMS collaboration is constructing the largest silicon tracker ever built with an active silicon area of 200 m^2 to provide robust charged particle tracking and vertex reconstruction within the 4T magnetic field of the CMS Solenoid. The design of the detector, the status of the construction and the performance of the substructures are reviewed.
The entire CMS silicon pixel detector will be replaced to operate at the High-Luminosity LHC. In this contribution, the new Tracker Endcap Pixel detector will be presented, focusing on a novel concept to provide both power and data connectivity to the modules through a disk-shaped PCB. As this part of the detector also features the longest serial powering chains in the CMS Phase-2 Inner Tracker, emphasis is put on serial powering results and the characterization of the signal integrity.
The era of High-Luminosity Large Hadron Collider will pose unprecedented challenges for detector design and operation. The planned luminosity of the upgraded machine is 5-7.5 x 10$^{34}$ cm$^{-2}$ s$^{-1}$, reaching an integrated luminosity of 3000-4000 fb$^{-1}$ by the end of 2039. The CMS Tracker detector will have to be replaced in order to fully exploit the delivered luminosity and cope with the demanding operating conditions. The new detector will provide robust tracking as well as input for the first level trigger. This report is focusing on the replacement of the CMS Outer Tracker syste…
The CMS silicon tracking system measures the trajectories of charged particles with a hit resolution of the order of microns in the pixel detector and tens of microns in the strip detector. One of the most important inputs for track reconstruction is the precision with which the tracker geometry is known. Therefore the position, orientation, and curvature of each tracker sensor must be precisely determined. Changes in the operating conditions can cause movements in the different substructures and also in the sensors. For maintaining the targeted precision, frequent corrections are needed, and …
At the High Luminosity LHC (HL-LHC), the CMS experiment will need to operate at up to 200 interactions per 25 ns beam crossing time and with up to 4000 fb-1 of integrated luminosity. To achieve the physics goals the experiment needs to improve the tracking resolution and the ability to selectively trigger on specific physics events. The CMS tracker upgrade requires designing a new detector to cope with the HL-LHC conditions. The new Outer Tracker is based on two types of silicon modules (strip-strip and pixel-strip). Each module type has a few types of high-density interconnect hybrid circuits…
In the high luminosity scenario of the LHC (HL-LHC), which will bring the instantaneous luminosity up to 7.5\,$\times$\,$10^{34}$\,cm$^{-2}$s$^{-1}$, ATLAS and CMS will need to operate at up to 200 interactions per 25\,ns beam crossing and reaching up to 4000\,fb$^{-1}$ of integrated luminosity. To achieve their physics goals the experiments will need to improve the tracking and vertexing capability and the ability to selectively trigger on specific physics events at reasonable thresholds. The upgrade of the CMS Tracker requires designing new inner and outer tracking detectors to cope with the…
The High-Luminosity upgrade of the LHC will see the accelerator reach an instantaneous luminosity of $7\times 10^{34} cm^{-2}s^{-1}$ with an average pileup of $200$ proton-proton collisions. These conditions will pose an unprecedented challenge to the online and offline reconstruction software developed by the experiments. The computational complexity will exceed by far the expected increase in processing power for conventional CPUs, demanding an alternative approach. Industry and High-Performance Computing (HPC) centres are successfully using heterogeneous computing platforms to achieve highe…
The strategies for and the performance of the CMS tracker alignment during the 2021-2022 LHC commissioning preceding the Run 3 data-taking period are described. The results of the very first tracker alignment after the pixel reinstallation, performed with cosmic ray muons recorded with the solenoid magnet off are presented. Also, the performance of the first alignment of the commissioning period with collision data events, collected at center-of-mass energy of 900 GeV, is presented. Finally, the tracker alignment effort during the final countdown to LHC Run 3 is discussed.
Experimental Study of Different Silicon Sensor Options for the Upgrade of the CMS Outer Tracker
在计划于2027年左右开始的大型强子对撞机（HL-LHC）的高光度阶段，加速器预计将提供高达$7.5\times10^{34}$ cm $^{-2}$ s $^{-1}$的瞬时峰值光度。预计在未来十年内，$3000$或甚至$4000$ ~fb $^{-1}$的总积分亮度将被交付给通用探测器ATLAS和CMS，从而显著增加LHC实验的发现潜力。CMS探测器将为HL-LHC进行重大升级，全新的跟踪探测器由外部跟踪器和内部跟踪器组成。然而，新的跟踪系统将暴露在比当前跟踪器高得多的辐射下，需要新的抗辐射传感器。CMS从2009年开始发起了一项广泛的辐照和测量活动，系统地比较不同硅材料的特性和外跟踪器传感器的设计选择。在18种不同的晶圆材料、厚度和生产技术组合上设计并实现了几种测试结构和传感器。在用中子和不同能量的质子辐照之前和之后，对装置进行电气表征，其中通量对应于在$3000$ ~fb $^{-1}$之后CMS外跟踪器的不同半径处预期的通量。所执行的测试包括使用$β$源、激光和光束扫描的研究。本文比较了HL-LHC硅传感器的不同选择的性能，重点是硅块材料和厚度。
Serenity-S1, a CMS Tracker Readout and Data Processing Card for HL-LHC
Imperial College London（帝国理工学院）；Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）；STFC Rutherford Appleton Laboratory（STFC卢瑟福阿普尔顿实验室）；University of Bristol（布里斯托大学）；Chinese Academy of Sciences（中国科学院）
The High Luminosity Large Hadron Collider (HL-LHC) at CERN is expected to collide protons at a center-of-mass energy of 14 TeV and to reach the unprecedented peak instantaneous luminosity of $7.5 \times 10^{34} \text{cm}^{-2} \text{s}^{-1}$ with an average number of pileup vertices of 200. This will allow the ATLAS and CMS experiments to collect a data sample with an integrated luminosity up to $4000\,\mathrm{fb}^{-1}$ during the project's lifetime. To adapt to these harsh conditions, the CMS detector will be substantially upgraded before starting the HL-LHC, a plan known as CMS Phase-2 upgrad…
The inner tracking system of the CMS experiment, which comprises Silicon Pixel and Silicon Strip detectors, is designed to provide a precise measurement of the momentum of charged particles and to reconstruct the primary and secondary vertices. The movements of the different substructures of the tracker detectors driven by the operating conditions during data taking, require to regularly update the detector geometry in order to accurately describe the position, orientation, and curvature of the tracker modules. The procedure in which new parameters of the tracker geometry are determined is kno…
In preparation for the High Luminosity LHC, the entire tracker detector of the CMS experiment will be exchanged as part of the Phase-2 Upgrade. The new Outer Tracker will comprise approximately 13,000 silicon sensor modules, of which 7608 are "2S modules" consisting of two parallel mounted silicon strip sensors, and 5592 are "PS modules" consisting of one pixel and one strip sensor in a single module. These modules provide tracking information to the Level 1 trigger by correlating the hit information of both sensor layers, allowing discrimination of particle tracks by their transverse momentum…
The strategies for and the performance of the CMS silicon tracking system alignment during the 2015-2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios.
The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5-7.5$\times10^{34}$ cm$^{-2}$s$^{-1}$. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000-4000 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13-14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, …
The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiati…
The next upgrade of the Large Hadron Collider (LHC) is planned from 2026 when the collider will move to its High Luminosity phase (HL-LHC). The CMS detector needs to be substantially upgraded during this period to exploit the fourfold increase in luminosity provided by the HL-LHC. This upgrade is referred to as the CMS Phase-2 Upgrade. A program of laboratory and beam test measurements, and performance studies based on the detailed simulation of the detector was carried out to support the decision of the technology of the sensors to be adopted in the different regions of the detector for the P…
