MDT Tube Assembly Manual.pdf

MDT Tube Assembly Manual The ATLAS MDT Group IHEP, Beijing May 20, 2003 Abstract This manual describes the facilities and procedures of the ATLAS monitored drift tube assembly at the Institute of High Energy Physics, Beijing. It also includes the endplug assembly procedure and the measurement of tube length and wire tension. Contents 1 Introduction 2 Tube Assembly Facilities 3 Daily Routine Check 4 Tube Assembly Procedure Appendix: Endplug Assembly Procedure 1 Introduction The ATLAS group at the Institute of High Energy Physics (IHEP), the Chinese Academy of Sciences, will construct 48 Monitored Drift Tube (MDT) chambers in the next two years. These chambers are categorized as two different types, BEE and BIS.8, with 32 and 16 chambers respectively. The total number of tubes to be constructed is about 7000, which requires that the tube production rate should reach 50 tubes per day. The assembled tubes must meet high quality specifications, as summarized in table 1. Item Specification Test method Tube length ??L?≤250μm Indicator Wire position ?X25μm EMMI system Wire tension 350g±15g Measurement of fundamental vibration model Gas leak rate 10-8bar?l/sec Helium leak detector Dark current 2nA DAQ-card Table 1. Quality control specifications for MDT tubes The task of tube assembly is to insert the endplug precisely into its position with high quality swaging between tube and endplug, and tension the wire to desired specification. All of the procedures are within the wiring room, part of the clean room that satisfies the following specifications: ?clean class better than 10,000 ?temperature 20OC±1OC ?relative humidity 45%±10% 2 Tube assembly facilities The tube assembly station (fig.1) mainly consists of following facilities: Fig.1 Wiring station Fig.2 Eastern (left) and western (right) sides of the wiring station ?Vacuum chucks/endplug holders/swaging coils Two vacuum chucks which hold the tube during tube w