标题： CMS缪子漂移室的漂移速度和压力监测 显示英文标题

标题： Drift velocity and pressure monitoring of the CMS muon drift chambers

摘要： CMS缪子室漂移管中的漂移速度是缪子轨迹重建和触发的关键参数。需要精确监测以检测其标称值的任何偏差。绝对压力的变化、气体混合物的变化或腔室气体被空气污染都会影响漂移速度。此外，温度和磁场也会影响其值。使用由RWTH亚琛IIIa建造的专用漂移速度室（VDC）获得的第一批数据被展示。另一个需要监测的重要参数是缪子漂移管腔室内的压力。差分压力不得超过某个值，并且绝对压力必须保持略高于环境压力，以防在泄漏情况下空气进入缪子漂移管腔室。最新的漂移速度监测结果进行了讨论。 显示英文摘要

摘要： The drift velocity in drift tubes of the CMS muon chambers is a key parameter for the muon track reconstruction and trigger. It needs to be monitored precisely in order to detect any deviation from its nominal value. A change in absolute pressure, a variation of the gas admixture or a contamination of the chamber gas by air affect the drift velocity. Furthermore, the temperature and magnetic field influence its value. First data, taken with a dedicated Velocity Drift Chamber (VDC) built by RWTH Aachen IIIA are presented. Another important parameter to be monitored is the pressure inside the muon drift tube chambers. The differential pressure must not exceed a certain value and the absolute pressure has to be kept slightly above ambient pressure to prevent air from entering into the muon drift tube chambers in case of a leak. Latest drift velocity monitoring results are discussed.