AI 中文总结
本文报告了ATLAS HL-LHC升级中102个sMDT缪子腔室在CERN的表面调试，验证了其低泄漏率、低暗电流、低噪声及高效率和空间分辨率，满足并超过设计要求。
AI 中文摘要
为了提高HL-LHC上第一级缪子触发效率，ATLAS桶部缪子谱仪内部小扇区中的监视漂移管（MDT）腔室将被替换为小直径缪子漂移管（sMDT）与阻性板腔室（RPC）的集成模块。本文报告了2025年在CERN对102个新sMDT腔室在安装最终前端电子学（包括为HL-LHC开发的新型放大器-整形器-甄别器（ASD）、时间-数字转换器（TDC）芯片和腔室服务模块（CSM））后进行的表面调试。调试包括气体泄漏率和高压暗电流的测量、集成平面度监测系统的测试、噪声表征，以及使用宇宙射线对探测器效率和空间分辨率的测量。在49152根管子中，因断掉的信号丝或气体泄漏而失效的管子少于0.1%。这些腔室超过了ATLAS的设计要求，每个腔室的气体泄漏率比规定的限值$9.3\times 10^{-3}~\mathrm{mbar\cdot liter/s}$低五倍，暗电流仅为每根管子约0.2~nA，平均通道噪声命中率低于30~Hz，在有效阈值为15个初级电子时，平均漂移管效率和空间分辨率分别为99%和$82~\mu\mathrm{m}$。
英文摘要
To improve the first-level muon trigger efficiency at the HL-LHC, the Monitored Drift Tube (MDT) chambers in the inner small sectors of the ATLAS Barrel Muon Spectrometer will be replaced with integrated modules of small-Diameter Muon Drift Tube (sMDT) and Resistive Plate Chambers (RPCs). This paper reports on the surface commissioning of 102 new sMDT chambers at CERN in 2025 following the installation of the final front-end electronics, including the new Amplifier-Shaper-Discriminator (ASD), Time-to-Digital Converter (TDC) chips, and Chamber Service Module (CSM) developed for the HL-LHC. The commissioning included measurements of gas leak rates and high-voltage dark currents, tests of the integrated planarity monitoring system, noise characterization, and measurements of detector efficiency and spatial resolution using cosmic rays. Fewer than 0.1\% of the 49152 tubes were found to be non-functional due to broken sense wires or gas leaks. The chambers exceed the ATLAS design requirements, with gas leak rates a factor of five below the specified limit of $9.3\times 10^{-3}~\mathrm{mbar\cdot liter/s}$ per chamber, dark currents of only around 0.2~nA per tube, average channel noise hit rates below 30~Hz, and average drift tube efficiency and spatial resolution of 99\% and $82~μ\mathrm{m}$, respectively, at an effective threshold of 15 primary electrons.
