ACES 2018 Sixth Common ATLAS CMS Electronics Workshop

ACES 2018: Sixth Common ATLAS CMS Electronics Workshop for LHC Upgrade april 24 -26, 2018 Overview of the Muon Readout Upgrades in ATLAS and CMS R. Richter, MPI Munich April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 1

Bibliography ATLAS • TDR for the Phase-II Upgrade of Trigger and DAQ, ATL-COM-DAQ-2017 -185, Dec. 2017 • TDR for the Phase-II Upgrade of the ATLAS Muon Spectrometer CERN-LHCC-2017 -017 ATLAS-TDR-026. - 2017. • TDR for the Phase-I Upgrade: New Small Wheel Technical Design Report, CERN-LHCC-2013 -006, 2013, URL: https: //cds. cern. ch/record/1552862. • Article: The ATLAS Experiment at the CERN Large Hadron Collider, JINST 3 (2008) S 08003 • TDR of the ATLAS muon spectrometer: Technical Design Report, CERN-LHCC-97 -022, CERN, 1997, URL: http: //cds. cern. ch/record/331068 CMS • • TDR for the Phase-2 Upgrade of the CMS Muon Detectors, CERN-LHCC-2017 -012, CMS-TDR-016 Technical Report, The Phase-2 Upgrade of the CMS DAQ, CERN-LHCC-2017 -014. CMS-TDR-018, 2017 Technical Report, The Phase-2 Upgrade of the CMS Tracker CERN-LHCC-2017 -009. CMS-TDR-014, 2017 Technical Report, CMS Technical Design Report for the Muon Endcap GEM Upgrade, CERN-LHCC-2015 -012, CMS-TDR-013, 2015 • TDR for the Muon Project CERN/LHCC 97 -32, CMS TDR 3, 15 December 1997 • Article: The CMS Experiment at the CERN LHC, JINST 3 (2008) S 08004 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 2

Infancy of two LHC Detectors (Lo. I 1992) Most of the chamber technologies not yet decided S. C. Solenoid Muon Detectors ATLAS • Three magnets: solenoid, Barrel & EC toroids • Calorimeters outside solenoid • Air-core toroid minimize multiple scattering • Focus on very high p. T single muons (> 100 Ge. V) April-25 th 2018 ACES 2018 Inner Detector Hadron Calorimeters EM Calorimeters CMS • One solenoid in an instrumented iron return • • yoke compact construction Calorimeters inside solenoid Focus on high Bdl in the Inner detector Overview of the Muon Readout Upgrades R. Richter 3

The Grown-ups, 2 decades later § Solenoid, r = 1 m, B= 2 T § Solenoid, r = 1, 2 m, B = 4 T § Nearly iron-free less multiple scatt. § Modular structure of barrrel out of 5 wheels § Little shielding in the forward region allows access for maintenance and upgrade higher BG of n‘s and g‘s in the hall § Tight enclosure by iron return yoke leads to § Very difficult access to inner parts of barrel good shielding against BG in the hall April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 4

Wish list for Muon Detectors at the HL-LHC • Selecting interesting event topologies at N times higher Lumi N * more luminosity requires: N times higher trigger rate to work at the same p. T - thesholds N times higher R/O bandwidth (1 st approxim. ) • Needed: smarter L 1 trigger decisions to keep rate down, i. e. select single muons with p. T > 20 Ge. V or di-muons with p. T > 10/10 Ge. V or 10/6 Ge. V • Smarter decisions require more latency requires better H/W, more frontend storage and higher R/O bandwidth redo all your electronics • Apply tight selection criteria to keep rate of permanent storage „low“. „Low“ means: E. g. 1 MHz L 1 10 k. Hz HLT @ 5 Mbyte/evt 50 Gbyte/s ! • Close acceptance holes and increase acceptance at high h requires an additional trigger budget beyond N requires more H/W April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 5

Inclusive m spectrum and L 1 trigger selectivity p. T = 20 Ge. V 10<PT<20 420 nb =4. 2 k. Hz Selectivity of momentum cut in the muon trigger is degrading with increasing threshold due to insufficient granularity in the trigger chambers and the spread in the IA vertex along z ! 2200 nb 22 k. Hz NB: 06. 09. 2021 400 nb 4 k. Hz 1034/(cm 2*s) 47 nb = 470 Hz = 10/(nb*s) ACES 2018 L = 1034 cm-1 s-1: fake L 1 triggers: p. T >10 Ge. V: ~400 nb = 4 k. Hz regular L 1 trigg. : p. T >20 Ge. V: ~47 nb = 0. 47 k. Hz Overview of the Muon Readout Upgrades R. Richter 6

What can we do to sharpen p. T selection? There a couple of possibilities to sharpen the p. T selection of the Muon trigger, which have not been capitalised on for the L 1 trigger in Run 1 -3: ATLAS: • Precision chambers (MDT & CSC) are not used at L 1 incorporate MDT precision coordinates into L 0 decision • Info from Calorimeters and ID not used for L 1 match ID track with m- candidate at L 1 Why not done before? Trigger chamber seed not available inside L 1 latency need > 6 ms L 0 latency in Run 4: 10 ms Doesn‘t work with old tracker: needs latency > 20 ms L 1 latency in Run 4: 30 ms CMS: • Precision and trigger chambers contribute both to L 1, but combination only in small region new R/O system for DT/RPC and CSC/RPC combination • Tracker not used for L 1 generate unseeded Track trigger to improve L 1 NB: pointing accuracy of muon candidate is limited by multiple scattering in iron yoke April-25 th 2018 ACES 2018 new R/O system for DT/RPC & CSC/RPC combination in Run 3 Needs NEW tracker & more latency Double layers structure in NEW ID L 1 latency in Run 4 = 12, 5 ms Overview of the Muon Readout Upgrades R. Richter 7

CMS Upgrade projects for Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 8

What will be new for the Muon detector? From: Josh Bendavid, CERN/LPC, Workshop on the physics of HL-LHC, Oct. 30, 2017 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 9

Voyage of a Muon across CMS (R/F view) Iron return yoke: B= 2 T B= 4 Tesla inside coil m-track sees the same Bdl inside and outside of the coil. In the outside the resolution is degraded by multiple scattering in the iron. April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 10

R-z cross section of the CMS detector & Phase-II additions m in Barrel 4 stations of 4 Layers of CSC precision RPC trigger chambers m in overlap region 4 stations of Drift Tube (DT) precision chamb. s 6 Layers of RPC trigger chambers m in high-h region New chambers for Phase-II to increase acceptance in the high-h region GE 1/1 will already be installed in LS 2 GEMs i. RPCs Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 11

Driving the Upgrade: Hit rates and TID doses at 5 * 1034 cm-2 s-1 (worst case, but no safety factors) EC RPC: EC CSC: 2 krad 10 krad 4. 5 k. Hz/cm 2 0. 2 k. Hz/cm 2 EC i. RPC: 3 krad 0. 7 k. Hz/cm 2 Barrel: 0. 12 krad 50 Hz/cm 2 GEM GE 1/1: 3 krad 1. 5 k. Hz/cm 2 GEM GE 2/1: 7 krad 0. 7 k. Hz/cm 2 From: CMS-TDR-016, p. 24, Table 1. 4 April-25 th 2018 GE 1/1 will already be installed in LS 2 GEMs i. RPCs GEM ME 0: 490 krad 48 k. Hz/cm 2 Phase-II ACES 2018 Overview of the Muon Readout Upgrades R. Richter 12

CMS: The Muon L 1 trigger flow in Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 13

Motivation for the Tracker trigger high p. T electron high p. T muon Candidate for a decay Higgs ZZ*(eemm) Tracker trigger combined with Muon trigger: Muon trigger selects the Muon candidates, Tracker does vertexing and exact p. T measurement April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 14

CMS: p. T resolution with the CMS Track trigger L 1 trigger efficiency at vs. p. T at thres. = 20 Ge. V L 1 trigger rate as a function of the p. T theshold Rate reduct. by ~5 in Barrel, ~10 in EC Red symbols: Muon stand-alone Black symbols: muons matched to Tracker tracks Full dots: Barrel Open dots: End. Cap Dramatic improvement of the L 1 p. T - selectivity when muon matched to ID-track April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 15

CMS: Upgrade of readout on existing chambers Drift Tube detectors DT (Barrel) • • Move trigger decision away from the frontend to USC, where higher complexity of trigger decisions is possible. E. g. , combination of DT and CSC in the overlap region (0. 9 < |h| < 1. 2) Frontend boards will only contain preamp, TDC and optical Transceiver Cathode Strip Chambers CSC (End. Cap) • • • Critical situation in high-h region: hit rate, latency, TID (~ 10 krad) Only the inner ring of CSCs (ME 1, 2, 3, 4/1) needs replacement of the frontend board for cathode and anode readout Use modern technology: replace SCAs by early digitization and digital pipeline Resistive Plate Chambers RPC (Barrel & End. Cap) • • Needs New Link system with higher R/O bandwidth New Link will have higher clock speed for RPC hit timing (25 ns 1. 56 ns) Replace all digital ASICs at the frontend (TCD; GOL, TTCrx) by FPGA, who will also contain a PLL to produce a local clock of 8*40 = 640 MHz (1. 56 lsb) Programming of frontend FPGAs via GBTx April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 16

R-z cross section of the CMS detector & Phase-II additions 4 stations of 4 Layers of CSC precision RPC trigger chambers 4 stations of Drift Tube (DT) precision chamb. s 6 Layers of RPC trigger chambers New chambers for Phase-II to increase acceptance in the high-h region GE 1/1 will already be installed in LS 2 GEMs i. RPCs Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 17

CMS: R/O architecture of NEW chambers in the End. Cap i. RPC (1. 8 < |h| < 2. 4) - RE 3/1 & RE 4/1 • • Smaller gas gap, 2 mm to 1. 4 mm lower HV will increase lifetime higher rate capabilities up to 2 k. Hz/cm 2 BUT: smaller signal new preamps in Si. Ge Both ends of the h-strips are read out, time difference gives h-resol. of a few cm New frontend ASIC in TSMC 130 nm with 64 channels/chip TDC is implemented in a FPGA 2 -layer GEM detectors (1. 6 < |h| < 2. 4) - GE 1/1 & GE 2/1 • • Consist of pairs of triple-GEM chambers of trapezoidal shape, covering 20° in F Rate capabilities up to a few MHz/cm 2 New 128 channel frontend ASIC chips (VFAT 3) containing charge sensing preamp, shaper and a constant-fraction discriminator. Time resol. < 7. 5 ns. Link to off-detector electronics via GBT 6 -layer GEM detectors (2. 4 < |h| < 2. 8) - ME 0 • Consist of 6 layers of triple-GEM chambers covering 20° in F total number of ME 0 chambers: 2 x 18 x 6 = 216 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 18

Performance figures of the NEW CMS chambers New i. RPC cham‘s Total Ionizing Dose (krad) Hit rate (Hz/cm 2) Produced for 3 700 Phase-II 2 triple-gap GEMs 3 1500 6 triple-gap GEMs 490 48000 7 700 Phase-II Main parameters for the new CSM detectors and key resolution figures From: Upgrade of the CMS Muon Detectors CMS-TDR-016, Table 1. 4 and 1. 11 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 19

Upgrade of the CMS DT for Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 20

BTI -Bunch & Track Identifier TRACO TRAck COrrelator Example: upgrade of the DT Readout for Phase-II Phase 0/1: Trigger primitives constructed locally from the TDC readings of the DTs Phase-II: The bare TDC readings are sent via a “Patch Panel” to USC for processing Current R/O Calorimeters Phase-II R/O Local generation of trigger primitives from the DT- TDCs, implemented in ASICs, housed in the “minicrates” Cu. OF Copper to Opt. Fib. Translator Twin. Mux: Combines trigger primitives from DT and RPC and sends them to the Track Finder April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 21

Readout Structure of the DT system April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 22

Flexibility of trigger primitives exchange April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 23

CSC Upgrade April-25 th 2018 ALCT = Analog Local Charged Track Bd. OTMB = Optical TMB CFEB = Cathode Front. End Bd. ODMB = Optical DMB TMB = Trigg. Mother Bd. : Anode-Cathode coincidence DMB = Data Acq. Mother Bd. FED = Frant. End Driver ACES 2018 Overview of the Muon Readout Upgrades R. Richter 24

Summary of CMS upgrade April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 25

ATLAS Upgrade projects for Phase-II April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 26

Artist‘s impression of ATLAS Barrel MDT ch‘s S. C. Solenoid Barrel toroidal coils Calorimeters End. Cap Toroid Trans. Rad. Tracker Silicon Det. April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 27

Diagram of the Level-0 Trigger Architecture April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 28

The ATLAS Muon Spectrometer in Phase-I m Chambers arranged along 6 projective trigger towers/side NB: Unlike CMS, the tracking chambers in ATLAS are arranged along 12 projective „towers“ towards the Interaction Point PRO: most high-p. T tracks do not cross tower boundaries CON: nightmare to access MDT in the inner barrel for maintenance & upgrade April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 29

Shortcomings of the present Muon R/O in Phase-II • Coarse spatial resolution of trigger chambers (~3 cm) leads to insufficient p. T measurement and pointing accuracy towards the IP. resolution and high fake trigger rates by sub-threshold muons in L 1 • Reduced efficiency of RPCs AND interaction region enlarged along z in Phase-II (5 15 cm) Need additional layer of RPC in the Barrel !! Make use high accuracy MDT coordinates (sub-mm) to sharpen L 1 trigger threshold need latency ~ > 6 ms !! • Insufficient R/O bandwidth in Phase-II for trigger rates and (locally) hit rates all R/O elx need replacement • Innermost chambers of the EI wheel not able to handle Phase-II hit densities replace by new chambers (New Small Wheel) April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 30

Newcomers in the Muon Spectrometer in Phase-II Upgrade of the ATLAS Muon detector: • • New thin-gap RPCs for robustness and p. T resol. in the barrel combined with new s. MDTs April-25 th 2018 Micro. Megas and s. TGC chambers for high rates and angular resolution at L 1 ACES 2018 New Triplet-RPCs in the Inner Barrel station combined with a new MDT-type (with 15 mm diam. Tubes) the s. MDT, will support higher rates Replacement of the Inner Station of the Endcap („New Small Wheel“) New technology for the NSW Micro. Mega and s. TGC with: • ~90 -160 mm spatial resolution • high-rate capability Most „intelligence“ goes to the expt. hall • flexibility for complex triggers • ease of upgrade and maintenance Overview of the Muon Readout Upgrades R. Richter 31

Fake muons in the present L 1 Endcap trigger A: prompt muon coming from the interaction point B: low-momentum particle spiralling across the EC toroid C: muon probably from p, K-decay Cleaning up of the EC triggers by accurate angle measurement of the NSW: • The NSW will only accept track A. • The NSW will reject track B, as there is no match to the Big Wheel candidate. • C will be rejected because the NSW track does not point to the interaction point April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 32

The L 1 selection in the endcap in Phase-II EI station EM station EO station („Small Wheel“) („Big Wheel“) („Outer Wheel“) EM MDT EO MDT • The NSW determines the track angle in the R/Z plane with ~1 mrad accuracy. • To match this accuracy of the angular measurement with the one in the „Big Wheel“, the MDT precision info will be needed for L 1 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 33

Stand-alone MDT trigger: why not? Problems: At high BG: accidental hits generate thousands of fake trigger candidates. Computational power too costy back in the 1990‘s. Additional difficulties: long drift time & non-linear r/t relation. Much more economic to use close-by hits from trigger chambers as seed. But needed more latency than available in Phase-I! Dec. , 8 th, 2009 Refinement of Level-1 with MDTs Muon week, dec. , 2009 R. Richter 34

Ro. I given by the TGC support MDT track finding The Ro. I from the TGC points to the relevant MDT tubes with about 3 cm accuracy ony few tubes need to be considered for track matching little influence of background hits Studies with real data show high efficiency for the reconstruction of the correct track in the MDT (see next slide) April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 35

Pointing accuracy of MDTs and TGCs in the Big Wheel • strack angle = sqrt(2) * spos. / lev. arm • Some numbers: (do not contain degradation pos. err. / modul lever arm track slope err. mm mm mrad Big Wheel alone 0. 1 252 0. 56 Big Wh. - Out. Whl. 0. 1 7480 0. 02 Big Wheel, high h 2. 2 1700 1. 8 Big Wheel, low h 11. 4 1700 9. 5 Location MDT from backgrounds) TGC • MDTs are < 1 mrad because of good position resolution • standard TGCs are > 1 mrad due to coarse wire grouping (6 -9 cm) • MDT may be used to sharpen L 1 trigger in the Big Wheel 06. 09. 2021 Upgrade of the L 1 Muon Trigger for phase II Richter Robert 36

The histogramming method and results from simulation Three categories: Good: Dm < 3 mrad Medium: Dm < 9 mrad Poor: Dm > 9 mrad The histogramming method: projecting the hits along the direction, given by the TGCs. This yields the most likely trajectory April-25 th 2018 ACES 2018 Quality of track reconstruction: defined as the deviation Dm of the reconstructed slope mrec from the true slope mgen Overview of the Muon Readout Upgrades R. Richter 37

Reduction of low-p. T fake L 0 triggers using MDT tracking info („MDT trigger“) Relative efficiency of the MDT 3 -station trigger with respect to the Phase-I first-level muon trigger vs. p. T, measured in the offline reconstruction. April-25 th 2018 ACES 2018 The h distributions of muon candidates selected with first-level p. T threshold of 20 Ge. V White distrib. : before Phase-II Blue: Using the MDT info at L 1 Green: Full off-line analysis Overview of the Muon Readout Upgrades R. Richter 38

The MDT readout architecture in Phase-II Underground Counting Room (USA 15) MDT Trig. Proc. : Hit Extract. Bd. : Sends the time stamps w. reduced resolution to the trigger processor Sends the time with reduced resolution to the MDT trigger processor Experimental Hall Preamp TDC: generate A timestamp For each signal Chamb. Serv. Module: collects the time stamps from one chamber April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 39

Diagram of the Level-0 Trigger Architecture April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 40

The RPC logic in one trigger tower RPC on-chamber L 1 generation needs several ASICs and complex cabling • • Coincidences between strips in RPC 2 and RPC 1 resp. RPC 3 to recognize low- and high-p. T tracks, separately for h and f strips. In addition, coincidences with stations in the adjacent trigger tower along h, to capture strongly curved tracks. System works well, but required considerable ON-chamber ASICs and cabling. Phase-II: All valid hits will be sent to the Sector Logic in USA 15. L 1 decision will run in modern FPGAs (similar concept like in the DT readout in CMS). April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 41

Architecture of the RPC based Barrel trigger in Phase-II Level-0 trigger and readout scheme of the RPC in the Barrel for Phase II. The on-detector DCT (Data Collector and Transmitter) boards sample the RPC front-end data and send the digitized data on GBT optical fibres to the off-detector Sector Logic boards which perform the trigger algorithm and readout logic. April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 42

The New Small Wheel April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 43

The New Small Wheel in the ATLAS EC The Micromega detectors The Micro. Mega detectors are precision and trigger detectors with a typical resolution of 90 mm In the angular range 0°-40°, which is achieved by charge division betw. adjacent strips. April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 44

The New Small Wheel in the ATLAS Endcap Spatial resol. (mm) The small Strip Thin Gap Chambers (s. TGC) Impact angle (°) Typical spatial resolution: Schematic drawing of 4 -layer TGC detectors • • At a strip pitch of 3. 2 mm a resolution of 90 – 160 mm for impact angles 0 -40° was measured. Interpolation btw. strips w. centroid or To. T The s. TGC internal structure April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 45

Global picture of the NSW readout ART Address in Real Time TDS Trigger Data Serializer On-detector: front-end boards to read out the 2. 5 M channels of NSW, the readout driver and trigger boards. April-25 th 2018 ACES 2018 ROC Readout Controller Off-detector: trigger processors and aggregator electronics to deliver data to the ATLAS TDAQ systems. Overview of the Muon Readout Upgrades R. Richter 46

The 64 -channel VMM chip is used for MM and s. TGC Block diagram of the VMM ASIC. The VMM chip (130 nm) determines peak time and amplitude of 64 channels April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 47

The New Small Wheel in numbers April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 48

Expected radiation doses in the NSW Total Ionizing Dose (TID) (blue) and neutron fluence (E>20 Me. V) (green) per year vs. radius at the NSW for luminosity 1034 cm-2 s-1 NB: Hottest TID region: 2 krad/year x 5 x 10 years = ~ 100 krad in 10 y‘s at 5 x 1034 100 krad no problem for ASICs in 130 nm GF April-25 th 2018 ACES 2018 From Radiation Task Force Summary report, 2005 49 Overview of the Muon Readout Upgrades R. Richter

Latency budget of the MM NB: The max. allowed latency in Phase-I is 1025 ns So there are only ~ 100 ns safety margin … Latency from the interaction point, through the MM trigger logic to the Sector Logic in USA-15 April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 50

Overall Muon trigger and readout scheme in Phase-II Muon trigger and readout scheme. The muon trigger decision is made in the endcap and barrel sector logic (SL) using data from the muon trigger chambers (TGCs and RPCs), from the Tile calorimeter, and from the MDT trigger processor. The trigger decisions of the SL’s are collected by the Mu. CTPi. All muon hit data are read out through the Front-End Link Interface e. Xchange (FELIX) and passed to the HLT and the down-stream readout system. April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 51

Summary and Conclusions • Development for Phase-II in ATLAS/CMS in full swing • Big potential for electronics upgrade, thanks to development of performance & cost since the early 1990‘s (cf. Lo. I 1992) • Also many upgrade options due to newly developped chamber technologies (GEMs, Micro. Megas, s. TGC, RPCs, s. MDTs) • Lots of technical challenges, but no apparent show stoppers • Time scale is very tight, everywhere, but good progress in most subsystems April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 52

SPARES April-25 th 2018 ACES 2018 Overview of the Muon Readout Upgrades R. Richter 53

R/F cross section of the CMS barrel Drift Tube Chambers (DT) RPC Trigger Chambers S. C. coil m-track sees the same Bdl inside and outside the coil. However, in the outside the resolution is degraded by multiple scattering in the iron of the return yoke April-25 th 2018 ACES 2018 14, 8 m Overview of the Muon Readout Upgrades R. Richter 54

TDAQ TDR p. 54 & 126 Run 1 Run 2 Run 3 Run 4 Regional Tracking Event Filter Rate k. Hz single m 9, 3 15, 5 15 38 38 1, 5 di - m 1, 9 5, 2 4 10 5 0, 2 single e 19 27 14 200 40 1, 5 di - e 6, 5 1, 7 5 40 10 0, 2 others 38, 3 25, 6 62 771 334 7, 0 total 75 75 100 334 10, 4 April-25 th 2018 ACES 2018 100%1059 --> 1% Overview of the Muon Readout Upgrades R. Richter 55

High- and low p. T tracks in the RPC of the Barrel Tracks with infinite momentum Pivot RPC 2 High-p. T trigger Pivot RPC 2 Low-p. T trigger April-25 th 2018 ACES 2018 The local RPC trigger is produced by a sequence of coincidences betw. hit strips in RPC 1&2 and RPC 1, 2&3 for low and high p. T, respectively. The acceptance of a track for a trigger is based on the angle w. r. t. an infinite momentum track coming from the IP (see next slide) Overview of the Muon Readout Upgrades R. Richter 56

Run 1 vs. 2 in the Barrel: significant reduction at large z Hz/cm 2 Barrel BI-layer BIS/BIL: tb. length 165/265 cm area: 500/800 cm 2 40 20 Hz/cm 2 Hit rates in Hz/cm 2 @ 1034 cm-2 s-1 Barrel M-layer BMS/BML: tb. length 305/353 cm area: 900/1600 cm 2 20 From Y. Chan, T. Koi, C. Colours indicate respective contributions from (red), n (blue), charged (green and yellow) May, 12 th, 2015 Predicted MDT hit rates in Phase II R. Richter Young, Expected Muon Spetrometer Background in Run 2, June 5, 2014 57

Run 1 vs. 2 in EM: significant reduction at small r EM wheel Hz/cm 2 Simulation Hit rates in Hz/cm 2 @ 1034 cm-2 s-1 100 Extrapolated from measurements! Hot region in EM with 60 -40 Hz/cm 2 @ 1034 cm-2 s-1 corresponding to 420 -280 Hz/cm 2 @ 7 *1034 cm-2 s-1 resulting in 140 -150 k. Hz/tube There is an apparent conflict between measurements and simulation for Run 1 Predicted rates from simulation may be a factor 2 too high ! May, 12 th, 2015 Predicted MDT hit rates in Phase II R. Richter 58