The BIS78 Resistive Plate Chambers upgrade of the ATLAS Muon Spectrometer for the LHC Run-3
The BIS78 Resistive Plate Chambers upgrade of the ATLAS Muon Spectrometer for the LHC Run-3
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LHC Run-3 的 ATLAS Mu 子光谱仪的 BIS78 电阻板室升级
DOI：
10.1088/1748-0221/15/10/c10026
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发表时间：
2020
影响因子：
1.3
通讯作者：
L. Massa
中科院分区：
文献类型：
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作者：
L. Massa
电阻板室（RPC）用于ATLAS实验中的μ子触发和中心区域的两个坐标测量。为了准备未来几年的LHC以更高的亮度运行，除了新的小轮项目预计将补充端盖区域的ATLAS μ子光谱仪外，一个较小的项目，称为BIS 78（来自桶内小部门），正在开发中，预计在LHC Long 2019-2020期间安装。BIS 78项目将通过在内桶偶数扇区（BIS 7和BIS 8）的边缘添加32个RPC三重态来加强ATLAS桶和端盖之间过渡区域中的假μ子排斥和μ子触发的选择性，因为该区域的特点是由于束晕质子产生的二次带电轨道和缺乏探测器仪器而导致的高速率。每个三联体将是一个由三个独立的RPC探测器组成的台站。由于可用空间狭窄，该项目预计将用由集成较小直径管（sMDT）和新一代RPC形成的μ子站取代用于该地区精确位置测量的现有监测漂移管（MDT），能够承受更高的速率并提供强大的独立μ子确认。这些新的RPC是基于新的设计的气体体积与更薄的气隙，更薄的电阻电极，更低的工作电压和新的高增益前端电子相对于传统的ATLAS RPC。除了在Run-3及以后的运行中使用外，该项目还作为高亮度LHC升级的试点测试特别相关，因为新RPC三重态的额外完整层预计将补充最内层平面的完整桶区域。介绍了该项目的核心，以及生产和测试结果的描述。还讨论了探测器基础设施和服务的详细信息沿着在长周期2（2019-2020）期间最终安装和调试的路线图。
Resistive Plate Chambers (RPCs) are used in the ATLAS experiment for the muon trigger and two coordinate measurements in the central region. In preparation for the coming years of LHC running at higher luminosity, besides the New Small Wheel project which is expected to complement the ATLAS muon spectrometer in the end-cap regions, a smaller size project, known as BIS78 (from Barrel Inner Small sectors), is being developed with a foreseen installation during the LHC Long Shutdown 2 (2019–2020). The BIS78 project will reinforce the fake muon rejection and the selectivity of the muon trigger in the transition region between the ATLAS barrel and end-caps by adding 32 RPC triplets on the edges of the Inner Barrel even sectors (BIS7 and BIS8) as this region is characterized by high rate due to secondary charged tracks generated by beam halo protons and a lack of detector instrumentation. Each triplet will be a station composed by three independent RPC detectors. Due to the narrow available space, the project foresees to replace the existing Monitored Drift Tubes (MDTs), used for the precise position measurement in this area, with muon stations formed by integrated smaller diameter tubes (sMDT) and a new generation of RPCs, capable of withstanding the higher rates and provide a robust standalone muon confirmation. These new RPCs are based on novel design of the gas volume with a thinner gas gap, thinner resistive electrodes, a lower operating voltage and new high gain front-end electronics with respect to the legacy ATLAS RPCs. Besides the use in Run-3 and onwards, this project is also of particular relevance as a pilot test for the High Luminosity LHC upgrade when an additional full layer of new RPC triplets is expected to complement the full barrel region in the innermost plane. The core of the project is presented, together with a description of the production and the test results. Details on the detector infrastructure and services along with a roadmap towards the final installation and commissioning during the Long Shutdown 2 (2019–2020) are also discussed.