Wotschack, J

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MDT Parameter Book(Draft 03)Joerg Wotschack, CERNNovember 28, 200711 MDT systemThe ATLAS muon system is split into two distinct parts: the barrel and the end-caps. In thebarrel the MDT chambers are arranged in three cylindrical layers around the beam axis that arecalled BI (Barrel Inner), BM (Barrel Middle), and BO (Barrel Outer). The end-cap chambers arearranged in four disks on each side of the interaction point perpendicular to the beam axis, calledEI (End-cap Inner), EE (End-cap Extra), EM (End-cap Middle), and EO (End-cap Outer). Anauxiliary set of chambers, called BEE (Barrel End-cap Extra), are installed on the cryostats ofthe end-cap toroids; they are constructed like barrel chambers although functionally they serve inthe end-cap system. Barrel chambers are of rectangular shape and arranged cylindrically aroundthe beam pipe; end-cap chambers are trapezoidal and arranged in planes orthogonal to the beampipe. Table 1 summarises some global quantities of interest for barrel and end-caps. The maintube parameters and the operational parameters of the MDT chambers are given in Table 2.Table 1: MDT chambers in numbers. The numbers in brackets refer to the pseudorapidity coveragein the EI plane.Parameter Barrel Endcap TotalNumber of chambers 656 494 1150Number of tubes 191 568 162 816 354 384Total wire or tube length (km) 620 463 1083Chamber area (m2) 3121 2399 5520Pseudorapidity coverage 0–1 1–2.7 (2.0) 0–2.7 (2.0)Chamber weight (t) 129 85 214Gas volume (m3) 415 310 725Table 2: Principal MDT chamber parameters.Parameter ValueTube material Aluminium (Aluman100)Outer tube diameter 29.97 mmTube wall thickness 0.4± 0.020 mmWire material W-Re (97%:3%); 3% gold platingWire diameter 50 µmWire pitch 30.035 mmGas mixture Ar:CO2 (93%:7%)Gas pressure 3 bar (absolute)Gas gain 2×104Wire potential 3080 VMaximum drift time ∼750 nsAverage tube resolution ∼75 µm21.1 BarrelFigure 1 shows a cross-section of the barrel part of the muon system. It illustrates the chambernaming and the numbering of the sectors.End-captoroidBarrel toroidcoilsCalorimetersMDT chambersResistive plate chambersInner detectorx7Sector 1234 5 68910111213141516yBILBISBIRBIMBOSBOLBMLBOF/GBMSBMF Rail + FeetBarrel ToroidCalorimeterFigure 1: Schematic view of the ATLAS muon spectrometer; cross-section view along the +zdirection.Figure 2 shows the local chamber coordinate system used in the muon system; the y- and z-axesalways point away from the interaction point.Local MDT coordinate systemTubes are counted along positive z (1,2,...,n)Figure 2: Definition of local chamber coordinate system. The z coordinate of the centre (wire) ofthe first tube of the chamber is +15 mm.Figures 3 illustrates the chamber naming and the numbering of the MDT chambers.32 4 6 8 10 12 14 16 18 2024681012 m0Large (odd numbered) sectors BILBMLBOLEELEML EOLEILCSC1 2 3 4 5 6123456EIL401 2 3 4 5 61 2 3 4 5 6TGCs12345123End-capmagnetRPCsyz12Small (even numbered) sectors EESEMSEOSRPCsy2 4 6 8 10 12 14 16 18 2024681012 m0BISBMSBOSEISCSC0TGCs1234512 End-capmagnet z1234561 2 3 4 5 61 2 3 4 5 6 BEE7 81 21 2 3 4 5 621Figure 3: Schematic side view of the ATLAS muon spectrometer depicting the naming and num-bering scheme; top: sector with large chambers; bottom: sector with small chambers.4The parameters describing the individual chambers are given in the following tables. Each chamberfamily comprises, in general, several chamber types that differ from each other in length (barrel)and/or width (end-cap). In the tables there is one column per type. In the barrel the chambertypes are named according to their family and length, e.g. a BIS of ’nomimal length’1 of 900 mm iscalled BIS900, etc. In the end-caps the chambers are numbered according to their radial position,e.g., EMS2 is the 2nd EMS chamber when counting from the beam axis.Table 3: Characteristics of BIS chambers; the numbers in brackets refer to sectors 2 and 16.Construction sites Beijing (China) AU Thessaloniki, U and NTU Athens (Greece)Type BIS480 BIS900 BIS1080Number of chambers 16 90 22Distance from beam axis (mm) 4620 (4635) 4550 (4635) 4550 (4635)Chamber length in z (mm) 496.7 916.2 1096.6Tube length (mm) 851.5 1671.5 1671.5Tube layers 1× 3 2× 4 2× 4Tubes/layer 16 30 36Spacer height (mm) - 6.5 6.5Chamber height (mm) 125 284 284Chamber weight (kg) 20 85 105Gas volume/chamber (l) 27 269 322Mezzanine boards/chamber 2 10 12T-sensors/chamber 3 10 10B-field sensors/chamber 2 2 21Nominal length is defined as the number of tubes/layer multiplied by 30 mm; in reality the chambers are longerby half a tube diameter (15 mm) because of the the staggering of the tube layers plus the sum of the additional gluegaps between the tubes.5Table 4: Characteristics of BEE chambers on the end-cap toroid cryostat.Construction site Beijing (China)Type BEE1440Number of chambers 32Distance from beam axis (mm) 4415Chamber length in z (mm) 1456.7Tube length (mm) 911.5Tube layers 1× 4Tubes/layer 48Spacer height (mm) -Chamber height (mm) 170Chamber weight (kg) 50Gas volume/chamber (l) 117Mezzanine boards/chamber 8T-sensors/chamber -B-field sensors/chamber 2 (4)Table 5: Characteristics of BIL chambers; the number in brackets refers to the two BIL1 chambersin sectors A09 and C09.Construction sites Cosenza, Pavia, Rome I (Italy)Type BIL720 BIL900 BIL1080Number of chambers 2 37 33Distance from beam axis (mm) 4949 4949 (5465) 4949Chamber length in z(mm) 735.8 916.2 1096.6Tube length (mm) 2671.5 2671.5 2671.5Tube layers 2×4 2×4 2×4Tubes/layer 24 30 36Spacer height (mm) 170 170 170Chamber height (mm) 416 416 416Chamber weight (kg) 120 140 160Gas volume/chamber (l) 343 429 515Mezzanine boards/chamber 8 10 12T-sensors/chamber 6 6 6B-field sensors/chamber 2 2 26Table 6: Characteristics of BIM and BIR chambers; the numbers in brackets refer to the four BIR1chambers. The BIR720 chambers (BIR5) have only 21 tubes per layer in Multilayer 1; the BIR4chambers (type BIR900) have only 27 tubes/layer in Multilayer 1.Construction sites Cosenza, Pavia, Rome I (Italy)Type BIM1080 BIR720 BIR900 BIR990 BIR1080Number of chambers 20 4 12 4 4Distance from beam axis (mm) 5373 6056 6056 6056 6056Chamber length in z(mm) 1096.6 735.8 916.2 1006.1 1096.6Tube length (mm) 1536.5 1536.5 1536.5 (2671.5) 1105.5 1105.5Tube layers 2×4 2×4 2×4 2×4 2×4Tubes/layer 36 21/24 27/30 (24/30) 33 36Spacer height (mm) 170 170 170 170 170Chamber height (mm) 416 416 416 416 416Chamber weight (kg) 120 85 100 (130) 95 100Gas volume/chamber (l) 515 185 235 (386) 195 213Mezzanine boards/chamber 12 8 10 12 12T-sensors/chamber 6 6 6 6 6B-field sensors/chamber 1 1 1 - -Table 7: Characteristics of BMS and BMF chambers. The numbers in brackets refer to the BMS4and BMS6 chambers in which the last group of 3×8 tubes in multilayer 1 is missing.Construction site JINR Dubna (Russia)Type BMS960 BMS/F1440 BMS1680 BMS/F1920 BMS/F2160Number of chambers 12 52 12 4 4Distance from beam axis (mm) 8095 8095 8095 8095 8095Chamber length in z (mm) 976.1 1456.7 1696.9 1937.2 2177.5Tube length (mm) 3071.5 3071.5 3071.5 3071.5 3071.5Tube layers 2×3 2×3 2×3 2×3 2×3Tubes/layer 32 48 (40) 56 64 72Spacer height (mm) 170 170 170 170 170Chamber height (mm) 364 364 364 364 364Chamber weight (kg) 140 190 215 240 260Gas volume/chamber (l) 395 592 (543) 691 790 889Mezzanine boards/chamber 8 12 (11) 14 16 18T-sensors/chamber 10 10 10 10 10B-field sensors/chamber 2 2 2 2 27Table 8: Characteristics of BML chambers.Construction site Frascati Nat. Lab. (Italy)Type BML960 BML1200 BML1440 BML1680Number of chambers 4 35 20 35Distance from beam axis (mm) 7139 7139 7139 7139Chamber length in z (mm) 976.1 1216.4 1456.7 1696.9Tube length (mm) 3551.5 3551.5 3551.5 3551.5Tube layers 2×3 2×3 2×3 2×3Tubes/layer 32 40 48 56Spacer height (mm) 317 317 317 317Chamber height (mm) 511 511 511 511Chamber weight (kg) 180 210 240 260Gas volume/chamber (l) 457 571 685 799Mezzanine boards/chamber 8 10 12 14T-sensors/chamber 10 10 10 10B-field sensors/chamber - - - -Table 9: Characteristics of BOS and BOF chambers. The numbers in brackets refer to the BOFchambers (sectors 12 and 14).Construction sites LMU and MPI Munich (Germany)Type BOF1200 BOS/F1440 BOS/F1920 BOS/F2160Number of chambers 4 6 16 62Distance from beam axis (mm) 10675 10569 (10675) 10569 (10675) 10569 (10675)Chamber length in z (mm) 1216.4 1456.7 1937.2 2177.5Tube length (mm) 3773.3 3773.3 3773.3 3773.3Tube layers 2×3 2×3 2×3 2×3Tubes/layer 40 48 64 72Spacer height (mm) 317 317 317 317Chamber height (mm) 511 511 511 511Chamber weight (kg) 220 270 300 350Gas volume/chamber (l) 606 728 970 1092Mezzanine boards/chamber 10 12 16 18T-sensors/chamber 18 18 18 18B-field sensors/chamber 2 2 2 28Table 10: Characteristics of BOG chambers. These chambers are located inside the detector supportfeet in sectors 12 and 14; they are T-shaped (except BOG8) and consist of long and short tubes.The dimensions in brackets in the table refer to the first and last six tubes in each tube layer, i.e.72 tubes out of the 240 total.Construction site Freiburg (Germany)Type BOG1200 BOG1200aNumber of chambers 14 4Distance from beam axis (mm) 10675 10675Chamber length in z (mm) 1216.4 1216.4Tube length (mm) 3771.5 (1201.5) 3771.5Tube layers 2×3 2×3Tubes/layer 28+12b 40Spacer height (mm) 317 317Chamber height (mm) 511 511Chamber weight (kg) 200 220Gas volume/chamber (l) 482 606Mezzanine boards/chamber 10 10T-sensors/chamber 28 24B-field sensors/chamber 2 2aBOG8; these chambers are installed in the last detector support feet on each side of the interaction point; thesechambers have no short tubes.b28 long and 12 short tubesTable 11: Characteristics of BOL chambers.Construction site NIKHEF Amsterdam (Netherlands)Type BOL1440 BOL1680 BOL1920 BOL2160Number of chambers 11 36 1 48Distance from beam axis (mm) 9500 9500 9500 9500Chamber length in z (mm) 1456.7 1696.9 1937.2 2177.5Tube length (mm) 4961.5 4961.5 4961.5 4961.5Tube layers 2×3 2×3 2×3 2×3Tubes/layer 48 56 64 72Spacer height (mm) 317 317 317 317Chamber height (mm) 511 511 511 511Chamber weight (kg) 300 340 380 420Gas volume/chamber (l) 957 1116 1276 1435Mezzanine boards/chamber 12 14 16 18T-sensors/chamber 18 18 18 18B-field sensors/chambera 2 2 2 2aB-field sensors are on all side A chambers, except in sector 13, and on C-side chambers in sectors 5 and 13.91.2 End-cap chambersFigure 4 shows the layout of the EI and EE chambers. Figure 5 shows the layout of the EM andEO chambers. The EM chambers are mounted on the movable MDT Big Wheel structures; TheEO chambers are fixed and mounted on the HO structures at the two cavern ends.EIL4EIS1EIS2(EIL3)EIL1EIL2CSC1324 68121416 10151311975EIL4(EIL5)EEL1EEL2EEL2'EES1EES21324 68121416 10151311975Figure 4: View of the EI (left) and EE (right) chambers from the interaction point onto side A.The EIS chambers of Sector 6 are not drawn to show the Small Wheel support structure.EML2EML5 EML4 EML3 EML1EMS1EMS2EMS3EMS4EMS512345678910111213141516EOL6EOL5EOL4EOL3EOL2EOL1EOS1EOS2EOS3EOS4EOS5EOS612345678910111213141516Figure 5: View of the EM (left) and EO (right) chambers from the interaction point onto side A.In Sectors 5 and 6 of the EO chambers the alignment components are shown. .The parameters of the EI and EE chambers are given in Tables 12, 13, and 14. The parameters ofthe EM and EO chambers are given in Tables 15, 16, 17, and 18.10Table 12: Characteristics of EIS and EIL chambers on the Small Wheels.Construction sites Boston (USA) Rome I (Italy)Type EIS1 EIS2 EIL1 EIL2 EIL3aNumber of chambers 16 16 16 16 12 4Distance from beam axis (mm) 2076 3371 2076 3191 4272.3 4272.3Distance from IP (z mm) 7261 7261 7675 7675 7675 7675Chamber length in r (mm) 1276.5 1096.2 1096.2 1096.2 375.4 375.4Tube length min (mm) 898.5 1276.5 1321.5 1861.5 2071.5 1741.5Tube length max (mm) 1222.5 1546.5 1771.5 2311.5 2071.5 1741.5Tube layers 2×3 2×3 2×3 2×3 2×3 2×3Tubes/layer 42 36 36 36 12 12Spacer height (mm) 121 121 121 121 121 121Chamber height (mm) 367 367 367 367 367 367Chamber weight (kg) 140 160 130 190 50 45Gas volume/chamber (l) 239 272 298 402 133 112Mezzanine boards/chamber 14 12 12 12 4 4T-sensors/chamber 8 8 8 8 - -B-field sensors/chamber - - - - - -aThe EIL3 chambers are not separate chambers; they are physically connected to the upper end of and are readout together with the EIL2 chambers, but were constructed separately.Table 13: Characteristics of EIL4 chambers; z = ±7641.5 mm.Construction sites Seattle (USA) Rome I (Italy)Type (Sectors) EIL4 (1,9) EIL4 (3,5,13) EIL4 (7) EIL4 (11,15) EIL5 (1,9)aNumber of chambers 4 6 2 4 4Distance from beam axis (mm) 5080.4 4720 4720 5080.4 4720Chamber length in r (mm) 1276.5 1636.9 1636.9 1276.5 375.4Tube length min (mm) 2531.5 2531.5 1651.5 1281.5 1536.5Tube length max (mm) 3071.5 3071.5 2371.5 1821.5 1536.5Tube layers 2×3 2×3 2×3 2×3 2×3Tubes/layer 42 54 54 42 12Spacer height (mm) 121 121 121 121 121Chamber height (mm) 367 367 367 367 367Chamber weight (kg) 190 230 185 140 40Gas volume/chamber (l) 630 784 582 349 99Mezzanine boards/chamber 14 18 18 14 4T-sensors/chamber 20 20 20 20 -B-field sensors/chamber 4 2 4 4 2aThe EIL5 chambers are not separate chambers; they are physically connected to the inner end of and are readout together with the EIL4 chambers, but were constructed separately.11Table 14: Characteristics of EES and EEL chambers.Construction site Protvino (Russia)Type (Sector) EES1 EES2 EEL1 EEL2 EEL2 (5)Number of chambers 16 16 14 14 2Distance from beam axis (mm) 5893 7370 6513 7749.7 6718Distance from IP (mm) 10276.5 10276.5 11322.5 11322.5 10518.5Chamber length in r (mm) 1456.7 1216.4 1216.4 1216.4 1456.7Tube length min (mm) 2014.5 2446.5 3361.5 3961.5 2446.5Tube length max (mm) 2374.5 2734.5 3841.5 4441.5 2806.5Tube layers 2×3 2×3 2×3 2×3 2×3Tubes/layer 48 40 40 40 48Spacer height (mm) 121 121 121 121 121Chamber height (mm) 315 315 315 315 315Chamber weight (kg) 150 140 170 190 160Gas volume/chamber (l) 423 416 579 675 507Mezzanine boards/chamber 12 10 10 10 12T-sensors/chamber 8 8 8 8 8B-field sensors/chamber 4 2 4 4 2Table 15: Characteristics of EMS chambers. All chambers are at a distance of z = ±13878.5 mmfrom the interaction point.Construction sites Boston (USA) Seattle (USA) Michigan (USA)Type EMS1 EMS2 EMS3 EMS4 EMS5Number of chambers 16 16 16 16 16Distance from beam axis (mm) 1770 3725 5680 7635 9590Chamber length in r (mm) 1937.2 1937.2 1937.2 1937.2 1937.2Tube length min (mm) 835.5 1411.5 1987.5 2563.5 3139.5Tube length max (mm) 1339.5 1915.5 2491.5 3067.5 3643.5Tube layers 2×3 2×3 2×3 2×3 2×3Tubes/layer 64 64 64 64 64Spacer height (mm) 170 170 170 170 170Chamber height (mm) 364 364 364 364 364Chamber weight (kg) 140 180 210 235 260Gas volume/chamber (l) 280 428 576 724 872Mezzanine boards/chamber 16 16 16 16 16T-sensors/chamber 8 20 20 20 20B-field sensors/chamber 4 2 4 4 212Table 16: Characteristics of EML chambers. All chambers are at a distance of z = ±14294.5 mmfrom the interaction point.Construction sites Seattle (USA) Michigan (USA)Type EML1 EML2 EML3 EML4 EML5Number of chambers 16 16 16 16 16Distance from beam axis (mm) 1770 3485 5440 7395 9350Chamber length in r (mm) 1696.9 1937.2 1937.2 1937.2 1937.2Tube length min (mm) 1186.5 2026.5 2986.5 3946.5 4906.5Tube length max (mm) 1906.5 2866.5 3826.5 4786.5 5746.5Tube layers 2×3 2×3 2×3 2×3 2×3Tubes/layer 56 64 64 64 64Spacer height (mm) 170 170 170 170 170Chamber height (mm) 364 364 364 364 364Chamber weight (kg) 150 210 250 290 330Gas volume/chamber (l) 348 629 876 1123 1370Mezzanine boards/chamber 14 16 16 16 16T-sensors/chamber 28 20 20 20 20B-field sensors/chamber 4 4 2 - -Table 17: Characteristics of EOS chambers; all chambers are at z = ±21820.5 mm.Construction site Protvino (Russia)Type EOS1 EOS2 EOS3 EOS4 EOS5 EOS6Number of chambers 16 16 16 16 16 16Distance from beam axis (mm) 2770 4485 6200 7915 9390 10865Chamber length in r (mm) 1696.9 1696.9 1696.9 1456.7 1456.7 1456.7Tube length min (mm) 1249.5 1753.5 2257.5 2761.5 3193.5 3625.5Tube length max (mm) 1681.5 2185.5 2689.5 3121.5 3553.5 3985.5Tube layers 2× 3 2× 3 2× 3 2× 3 2× 3 2× 3Tubes/layer 56 56 56 48 48 48Spacer height (mm) 170 170 170 170 170 170Chamber height (mm) 364 364 364 364 364 364Chamber weight (kg) 140 160 180 180 190 210Gas volume/chamber (l) 330 443 557 567 651 734Mezzanine boards/chamber 14 14 14 12 12 12T-sensors/chamber 8 8 8 8 8 8B-field sensors/chamber - - - - - -13Table 18: Characteristics of EOL chambers; all chambers are at z = ±21404.5 mm.Construction site Protvino (Russia)Type EOL1 EOL2 EOL3 EOL4 EOL5 EOL6Number of chambers 16 16 16 16 16 16Distance from beam axis (mm) 2770 4485 6200 7675 9150 10625Chamber length in r (mm) 1696.9 1696.9 1456.7 1456.7 1456.7 1456.7Tube length min (mm) 1681.5 2641.5 3481.5 4201.5 4921.5 5641.5Tube length max (mm) 2401.5 3361.5 4081.5 4801.5 5521.5 6241.5Tube layers 2× 3 2× 3 2× 3 2× 3 2× 3 2× 3Tubes/layer 56 56 48 48 48 48Spacer height (mm) 170 170 170 170 170 170Chamber height (mm) 364 364 364 364 364 364Chamber weight (kg) 170 210 215 235 260 285Gas volume/chamber (l) 459 675 729 868 1007 1146Mezzanine boards/chamber 14 14 12 12 12 12T-sensors/chamber 8 8 8 8 8 8B-field sensors/chamber - - - - - -14

MDT Parameter Book

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