INNOVATIVE MUON DETECTORS FOR HLDRAFT LHC UPGRADE DRAFT

INNOVATIVE MUON DETECTORS FOR HLDRAFT LHC UPGRADE –DRAFT IFD 2014 MUON WG 2 13703/2014 1

INTRODUCTION • STRONG PRESENCE OF ITALIAN GROUPS IN THE MUON SYSTEM OF THE 4 LHC EXPERIMENTS • LEADING MOST OF THE R&D ACTIVITIES FOR RPC, GEMS AND MMGAS • THE PROJECT PRESENTED FOR PHASE 1 AND PHASE 2 REQUIRING INNOVATIVE DETECTORS • FOR EACH TECHNOLOGY WE REPORT: • ANALYSIS OF THE STATE OF THE ART AND FEATURES • SHARED R&D PLANS ACROSS EXPERIMENTS • EXPERIMENT SPECIFIC NEEDS PLANS ANDR&DS • JOINT GAS STUDIES AND FACILITIES 12/26/2021 2

RPCS AT THE LHC EXPERIMENTS 12/26/2021 3

PRESENT RPCS PERFORMANCE SUMMARY projects and tech frozen 15 years ago huge improvement is now possible • FOUR RPC SYSTEMS INSTALLED AT LHC EXPERIMENTS • PRESENT DESIGN PERFORMANCE: COMMON FOR ATLAS, CMS AND ALICE MUONS • 300 M C/CM^2; 100 HZ/CM^2 FOR 10 YEARS; • 1 KHZ/CM^2 LIMIT RATE CAPABILITY NOT SUITABLE FOR CONTINUOUS OPERATION; • ~1 CM X 1 NS SPACE X TIME RESOLUTION • 2 MM GAS GAP WITH 2 MM HPL (IMPROPERLY CALLED BAKELITE) ELECTRODES • ALICE TOF MRPCS DESIGN AND PERFORMANCE • TESTED UP 1 KHZ/CM^2 • ~1 CM X 50 PS SPACE X TIME RESOLUTION • DETECTOR ELEMENT: TEN 0. 25 MM GAS GAP WITH 0. 4 MM FLOATING GLASS ELECTRODES • WORKING MODE : SATURATEDAVALANCHE, A VERY EXTENDED WORKING MODE… • ALICE TOF 6 P C /AVALANCHE DELIVERED 40 FC FE THRESHOLD • ATLAS AND CMS 30 PC /AVALANCHEDELIVERED 50 -100 FC FE THRESHOLD • ALICE MUON 100 PC /AVALANCHEDELIVERED NO FE AMPLIFICATION… • STANDARDS OPTIMIZATION DRIVEN BY THE KNOWLEDGE AVAILABLE, NEEDS AND FE PERFORMANCE 4

NEW GENERATION RPC R&D FRAMEWORK • IN THE LATE ‘ 90 THE INFN GROUPS • EOI IN THE AIDA 2020 PROGRAM DEFINED COMMON RPC STANDARDS FROM ALICE+ATLAS+CMS BECOMING A WORLD REFERENCE • “CLASSIC” OPTIMIZED FOR LARGE SURFACES FOR MUON AND CR SYSTEMS (ALICE, ARGO, ATLAS, BABAR, CMS, OPERA, INO) • “TIMING” OPTIMIZED FOR TOF APPLICATIONS ALICE TOF AS EXAMPLE IN LHC • THE STANDARD WAS FOUNDED ON : • COMMON CONSTRUCTION SITE AND PROCEDURES , (E. G. G. T. ) • COMMON QUALIFICATION SITE (GIF) • SUCCESS RPC IN ALLLHC PERFORM VERY WELL. • AFTER ABOUT 15 YEARS WESTARTED AGAIN A COMMON EFFORT TO FACE THE CHALLENGE OF HL-LHC AND OTHER NEXT COMING EXPERIMENTS. • WHAT’S NEXT…? • INDUSTRIAL TEMPLATE FOR NEXT GENERATION RPCS • THE KEY OF THIS R&D IS: • • TO SCALE UP THE “CLASSIC”RPC PERFORMANCE PRODUCE A COMMON EXECUTIVE DESIGN DOCUMENT FOR THE PRODUCTION COMPANIES • IT WILL DEEPLY REVISE: • THE FE DESIGN AND TECHNOLOGY • GAP FORM FACTOR, MATERIALS AND CONSTRUCTION DETAILS • THE MIXTURE • MECHANICAL STRUCTURE CERN BASED COLLABORATION PROPOSAL, RDXY • THE RPC WAS BORN INITALY AND NOW HAS PASSPORTS IN ALL THE CONTINENTS… • IN ORDER TO STRENGTHEN THE INTERNATIONAL COLLABORATION AMONG RPC GROUPS AN ADEQUATE INSTRUMENTS IS AN R&D COLLABORATIONRD ( XY) AT CERN FOLLOWING THE MODEL OF THOSE ALREADY MADE FOR LHC • THIS WAS ENDORSED IN THE RECENT RPC 2014 CONFERENCE AT TSINGHUA UNIVERSITY (BEIJING)

RPC R&D FOCUSES AND INITIATIVES Prompt multiplication in uniform field: gas target and amplification coincide Resistive electrodes: spark free • ADVANTAGES: R&D themes and initiatives • HIGH SPACE TIME LOCALIZATION OF EVENTS ANDWEAK DEPENDENCY ON THE IMPACTANGLE • WIDE RANGE FOR SATURATED AVALANCHE 1 PC 100 P C WIDE VARIETY OF DETECTORS WORK THE SAME WAY • EASY TO BUILD IN LARGE DIMENSION AND DIFFERENT E 0 SHAPES E E 0 • d 1 g d 2 IMPOSED LIMITS: • THE FAST SIGNAL COMPONENT IS << THEN THETOTAL CHARGE • STATISTICAL FLUCTUATIONS WIDE CHARGE SPECTRUM • NEED OF QUENCHING AND ELECTRONEGATIVE GASES • NEED OF HIGHLY RESISTIVE AND SMOOTH ELECTRODES TO AVOID DEVELOPING SPARKS AND NOISE Form Factor: gas target and electrode thickness and segmentation (ATLAS and CMS) Thinner gas gap better timing, position and lower charge Thinner electrodes better S/N on the pickup and position Multi-gap better efficiency timing and charge spectrum Electrode material: lower resistivity materials (CMS) Low resistivity glass higher rate multi-gap Low resistivity HPL (Bakelite) higher rate “classic” New Gas studies(Alice, Atlas, CMS): Replace Freon cheaper and environmental friendly New gases ageing properties See WG 4 New FE concept: (ATLAS) New design: Fast signals, sensitive and low capacitance noise Si-Ge technology: extremely low noise and high speed 6

NEW RPC DEVELOPMENTS HIGH PERFORMANCE FE production chamber CMS Prel imin resu ary lts New design + new Si-Ge (0, 1 p. C) New design FE ATLAS lab + GIF tests Total charge vs HVeff with working point highlighted. In red: ATLAS FE. In blue: new BJT Si FE ATLAS FE

ATLAS RPCS FOR HL-LHC RUNS Present System and needed enhancements • SYSTEM CONCEIVED IN THE EARLY NINETIES AS A FAST, ROBUST ANDSIMPLE DEVICE • DESCRIPTION IN WG 1 SLIDES • ONLY 2 STATIONS LIMITED REDUNDANCY • CERTIFIED AT 100 HZ/CM^2 FOR 10 YEARS (INCLUDING SAFETY FACTOR) Performance requirements in the LOI for Phase 2: REGION A new trigger scheme will be implemented see WG 3 slides An p. T higher selectivity not achievable with the present trigger design Improve the poor acceptance in the barrel is (73%) due to the barrel toroid ì • INCREASE REDUNDANCY WITH HIGH PERFORMANCE RPCS IN THE INNER preserve longevity of the old detectors • WOULD SOLVES ALL THE ISSUES • FORESEEN IN THE ORIGINALATLAS PROPOSAL BUT DOWN-SCOPED IN 1997 TDR Minimal Good track Today Good track in new scheme Expected 300 Hz/cm^2 3 times more than the design safety factor: Switch to 2/4 majority a much easier working point a factor of 3 lower current If gap efficiency 80% • 3/4 majority 82% • 2/4 majority 98 % • • 9 layers instead of 6 4 chambers instead of 3 2 stations 6 layers 3 stations 9 layers

ATLAS SPECIFIC R&D FOR PHASE 2 OLD CHAMBERS ENHANCEMENT SEE WG 1 SLIDES • IMPROVE THE SPACE RESOLUTION AT ~ MM THROUGH TOT WITH THE NEW READOUT (R&D ONGOING) WG 3 SLIDES NEW CHAMBER PERFORMANCE A NEW RPC STANDARD IS NEEDED 1 KHz/cm^2 expected Rate certification for 2 KHz/cm^2 < 0. 1 mm space resolution Space very limited for self supporting chambers (structural) < 0. 4 ns time resolution WORKING PRINCIPLE: • THE PHYSIC SIGNAL IS VERY LOCALIZED • CENTROID METHOD USING LARGE STRIPS • WORKS IF THE FE S/N IS SUFFICIENT • STRIP PITCH TO BE OPTIMIZED ON THE CHARGE SPREAD • SEVERAL OPTIMIZATIONS ARE STILL POSSIBLE AND THE RESULT IS VERY PRELIMINARY

NEW CMS RPCS FOR HL-LHC RUNS üRPCs are considered to be installed in the RE 3/1 and RE 4/1 stations of CMS during LS 3 Technology choice will be driven by the physics case Wide spectrum research to find the right solution basing on the experiment request evaluating different options: HPL vs. Low resistivity glass multigap vs. bigap, FE amplifier performance the multi-gap option depends on the possible impact on the Physics Preliminary results show that the expected rate in RE 3/1 and RE 4/1 should be < 600 Hz/cm 2 Main concern for their installation was their rate capability and survivability New chambers to be qualified for 10 years at ≈ 2 k. Hz/cm 2 including a safety factor similar request as for ATLAS Phase 2

PRESENT R&D IN CMS Improvements on the present detector gas, cooling, mechanics and services Develop high rate capability RPCs for the high η region. Different options: RPC Low resistivity HPL (109 – 1010 Ωcm) Low resistivity MRPCs for high resolution timing option GIF++ tests to study the performance and stability of the chambers at to 3000 fb-1. WG 4 presentation high rate and up Single gap option Mylar layer (50μ) Bakelite RPC (2014 -2016): ütest smaller gap (< 2 mm) to reduce HV working point üImproved gas distribution and components üNew FE electronics with ATLAS chip see common R&D slide PCB (1. 2 mm)+ASICs(1. 7 mm) PCB support (polycarbonate) PCB interconnect Readout pads (1 cm x 1 cm) Readout ASIC (Hardroc 2, 1. 6 mm) Gas gap(1. 2 mm) Mylar (175μ) Glass fiber frame (≈1. 2 mm) Ceramic ball spacer glass (1. 1 mm) + resistive coating Multigap option: üa variation of the double gap used for CMS: “double tri-gaps” GLASS RPC R&D: ü(1010 Ωcm) glass for high rate üSmoother electrode surfaces reduces the intrinsic noise üImproved electronics CMS R&D #12. 01

The ALICE muon spectrometer after LS 2 RUNNING CONDITIONS: 100 H K Z INTERACTION RATE IN PB-PB (AND 2 MHZ PP) GOAL #: DETECTOR PERFORMANCE AND SAFE LONG-TERM OPERATION IN SUCH A SCENARIO EXPECTED AVERAGE (MAX) COUNTING RATE INPB-PB AT 100 H K Z: 75 150 ( ) HZ/CM 2 EXPECTED AVERAGE (MAX) COUNTING RATE IN PP AT 2 MHZ: 60 150 ( ) HZ/CM • R&D RESULTS (2006) • IN THE PRESENT WORKING CONDITIONS NUCL. PHYS. B P. S. 158 80 HZ/CM 2 RATE CAPABILITY ~80 • AGEING TESTS UP TO 500 MHITS/CM 2 (50 M C/CM 2), I. E. ABOUT 1 YEAR @ 50 HZ/CM 2 • DETECTOR OPERATION IN THE PRESENT CONDITIONS EXPECTED POST-LS 2 RUNNING CONDITIONS: IS NOT COMPATIBLE WITH THE • UP TO NOW THE DETECTOR WORKED IN EXTREMELY SATURATED AVALANCHE MODE TO AVOID THE USE OF AFE AMPLIFIER. q Ongoing studies § Total charge: Q~10 -30 p. C (goal) vs. 100 p. C presently § Fast charge on the strip @FEE threshold: q~50 -100 f. C (goal) Þ reduce RPC ageing Þ improve rate capability Þ Release the requirements on the gas q Use the new ATLAS FE ASIC q build a custom ASIC (FEE Rapid Integrated Circuit, FEERIC) • RPC FE SOLUTION AVAILABLE TO SCALE DOWN THE CHARGE PER COUNT TO A SAFE VALUE 12

GEMS AT THE LHC EXPERIMENTS 12/26/2021 13

GEM: principle of operation The GEM (Gas Electron Multiplier) [F. Sauli, NIM A 386 (1997) 531] is a thin (50 μm) metal coated kapton foil, perforated by a high density of holes (70 μm diameter, pitch of 140 μm). By applying 400 -500 V between the two copper sides, an electric field as high as ~100 k. V/cm is produced into the holes which act as multiplication channels for electrons produced in the gas by an ionizing particle. The 50 μm deed channels are rapidly freed by the positive ions and ready for a new particle making the GEM detectors able to operate in very high particle fluxes. Gains up to 100 can be easily reached with a single GEM foil. Higher gains (up to 104) and/or safer working conditions are usually obtained by cascading two or three GEM foils. 14

The Triple-GEM detectors Since LHCb has been the first LHC experiment using GEMs, the information derived from their operation is of crucial importance for the design of any other detector based on the same technology at LHC (i. e. CMS), or more generally at any experiment in harsh environment. Non-standard gaps: 3/1/2/1 mm - T 1 is 1 mm to decrease the probability that an ionization in T 1 could trigger hits in advance worsening the time resolution. - Induction gap is 1 mm to have short signals 2 Or-ed Innovative gas mixture: Ar/CO 2/CF 4 at 45/15/40 detector ✓ The high ionization density and high drift velocity provided by s CF 4 allows a single detector efficiency in 25 ns larger than 96% and high time resolution; ✓ No aging effects observed up to 2. 2 C/cm 2. LHCb GEM detectors were operated with a luminosity as high as 1033 cm 2/s i. e. up to a particle rate above 1 MHz/cm 2 without showing any deterioration of their performance. These values are well below the rate capability measured in lab with an X-Ray tube. rate capability 50 MHz/cm 2 15

LHCb Muon System. Upgrade • Due to the very high hit occupancy expected at the upgrade luminosities (HL) and the increased Lower-Level-Trigger (LLT) output rate, station M 1 will be removed. • In the hottest regions of M 2 (M 3) rates well below 1 MHz/cm 2 are foreseen; • MWPC in these regions can be substituted with GEM detectors; M 2 R 1 M 3 R 1 # chambers / size Total GEM foil area 48 ~ 30 x 25 cm 2 48 ~ 32 x 27 cm 2 ~12 m 2 ~13 m 2 • A new GEM technique developed by R. de Oliveira (TE MPE - CERN Workshop) allows the production of large area GEM. Single mask Double mask • Same base material • Hole patterning in Cu • Polyimide etch • Bottom electro etch • Second Polyimide Etch It is essentially based on two technical “tricks”: the single mask & the cathode protection 16

Technology improvements: NS 2 assembly Rui de Oliveira at CERN developed a new detector assembly scheme inspired to LHCb-GEM “stretching technique” of GEM foils, that is suitable for massproduction and industrialization of the whole construction process. The idea is to re-scale and adapt the design of the GEM stretching tool in order to be embedded inside the detector itself. O-ring GND Free to slide GND External screws to adjust stretching Drift electrode Embedded nut Advantages: - No gluing, nor soldering - No spacers in the active area - Re-opening of detectors if repairs needed GEM attaching structure (4 pieces defining gaps) 17

The CMS muon upgrade scenario GE 1/1 GEM technology - High trigger performance during of late Phase I and throughout Phase II -Demonstrator in YETS 2016 approved • Plan for installation in LS 2 • TDR by October 2014 1. 55 < | | < 2. 18 - ME 0 GEM technology to ensure efficient trigger coverage up to | = 2. 4 and reconstruction up to | = 3. 5 -4 ME 0 super-module wedge will consist 6 times the single detector. Baseline: triple GEMs design R&D: new technology? (high time resolution) Total width of 30 cm: 2 x 18 chambers 20 -degrees/chamber in phi: 18432 readout channels – strips running one directional in φ Possible R&D: In order to fit in 30 cm exploring the “doublet system”: two back-to-back single Triple GEM Chamber with ONE drift electrode and readout on both sides - Station GE 2/1 GEM technology to ensure trigger and reconstruction efficiency 1. 55 < | | < 2. 45

GEM GE 1/1 R&D 2010 Generation I The first 1 m-class detector ever built but still with spacer ribs and only 8 sectors total. Ref. : 2010 IEEE (also RD 51 Note-2010 -005) 2011 Generation II First large detector with 24 readout sectors (3 x 8) and 3/1/2/1 gaps but still with spacers and all glued. Ref. : 2011 IEEE. Also RD 51 -Note-2011 -013. 2012 Generation III The first sans-spacer detector, but with the outer frame still glued to the drift. Ref. : 2012 IEEE N 14 -137. 2013/14 Generation IV Generation V The current generation that we have built two of at CERN so far, with four more to come from the different sites. No more gluing whatsoever. Upcoming papers from MPGD 2013; And IEEE 2013. The upcoming detector version that we will install. One long and one short version. Optimized final dimensions for max. acceptance and final eta segmentation. Installation of dummy chambers GEM foils production Single mask technology etching effects dramatically on lowering the foils production costs keeping the same performance of double mask GEM. Large foils dimensions and NS 2 technology must be validated in terms of long term performance stability. GEM foils mechanical tension and GEM gaps uniformity on chamber performances must be verified (Apollinari review committee questions). R&Ds are ongoing to answer to these points

GEM project achievements Performance Detector efficiencies ~98% Time resolution ~4 ns Spatial resolution of about 290μm with VFAT 2 (digital) and <110μm APV (analog) readout chip Operation of GEMs in magnetic field Gas mixture Ar/CO 2/CF 4 (45/15/40) Rate capability ~105 Hz/cm 2 Good performance in test-beams at CERN SPS and FNAL Technology and assembly Validation of single-mask technology Production of large area GEM foils (GE 1/1 -type) NS 2 technique for GEM assembly Integration Dummy GEMs for trial installation

R&D Activities ongoing General R&D on GEMS detectors and gas properties Set of measurements in progress: Charge, timing, gas mixtures study Custom electronic tool developed for GEM foils and readout plane QC Present on-site infrastructures (clean room and X-ray facility for gain uniformity study) One GEM based 10 x 10 cm 2 detector built and under characterization readout by a board based on the GASTONE chip for a total of 128 channels Anodic readout planes custom designed for spatial resolution study Measurements with different gas mixtures Two GEM 1/1_IV prototypes built and under characterization Studies and test on optimal HV – LV power distributions. R&D on Materials and Stretching of GEMS Specific question by Apollinari review CMS committee Safe operation of GEM detector made of composite materials Over 20 years, in harsh high-rad environment, gas eco-friendly Develop simple, cost-effective, mass production tool to assess GEM foils’ planarity and parallelism within 100 μm over the few mm gaps and large area (~m 2) Discover if an in situ monitoring of stretching and planarity is possible Moiré setup Characterization of materials pre- and post- irradiation (Kapton, O-rings, piping, etc) New eco-gas Characterize stretching of GEMs, develop optical Moire’-based techniques Install optical sensors permanently on GEM chambers to monitor foils mechanical tension during operation (? ) Preliminary R&D results 100 um 300 um G. Saviano et al. Study of GEM film and foil materials… SIENA 2013, accepted by JINST V. A. Franchi et al. , Measurement of Diffusion coefficient…, INFN-13 -09/LNF G. Raffone, CHE and related stress in GEM foils, INFN-13. 11/LNF G. Raffone, , CMS trapezoidal GEM foil stuctural analysis, INFN-10/20(IR)

MMGAS IN THE ATLAS NEW SMALL WHEEL 12/26/2021 22

ATLAS MMGAS IMPLEMENTATION • Large Micromegas prototype (1 x 2 m 2) 2 OF • PROCESS OF BUILDING 1200 M DETECTOR ONGOING (MODULE 0 COMPLETION: END OF 2014, MASS PRODUCTION STARTS IN 2015) • PROPOSALS TO USE MICROMEGAS FOR PHASE 2 UNDER EVALUATION

ATLAS SPECIFIC R&D ON MMGAS Tracking capability for inclined tracks • COMBINATION OF TWO TECHNIQUES: • CHARGE CENTROID (DOMINANT AT ANGLES <8 DEG. ) • Track inclination: 30 degrees ΜTPC MODE (DOMINANT AT ANGLE>10 DEG) • AN OVERALL SPACE RESOLUTION <100ΜM CAN BE ACHIEVED WITH A 400 ΜM STRIP PITCH • ANGULAR RANGE OF NSW: ~10 -30 DEG. MMGAS immune to sparks • SPARK INTENSITY CAN BE DRASTICALLY REDUCED (UP TO A FACTOR 103) BY ADDING A RESISTIVE LAYER ON THE R/O STRIPS • SPECIFIC R&D TO OPTIMIZE THE RESISTIVE PROTECTION • EXCELLENT RESULTS Test in neutron beam (106 Hz/cm 2)

INDUSTRIALIZATION EFFORT • INDUSTRIAL PROCESS IS BEING DEFINED WITH A NUMBER OF TECHNOLOGICAL IMPROVEMENTS Drift panel RO panel • NEW CONSTRUCTION METHOD • • MESH MOUNTED ON THE DRIFT PANEL MECHANICALLY FLOATING MESH • INDUSTRIAL PROCESS BASED ON FEW STEPS ALREADY IN HAND TO INDUSTRIES • RESISTIVE FOILS PRODUCED SEPARATELY (WITH SPATTERING TECHNIQUE) AND GLUED ON THE READOUT PLANE • CHALLENGING CONSTRUCTION CONSTRAINTS: PCB ALIGNMENT AND PANEL FLATNESS VERY DEMANDING RMS) (30 UM

GAS STUDIES 12/26/2021 26

THE “ECOLOGICAL” GAS MIXTURES ISSUE • THE EUROPEAN COMMUNITY HAS PROHIBITED THE PRODUCTION AND USE OF GAS MIXTURES WITH GLOBAL WARMING POWER > 150 GWP ( (CO 2) = 1) ÜTHIS IS VALID MAINLY FOR INDUSTRIAL (REFRIGERATOR PLANTS) APPLICATIONS ÜSCIENTIFIC LABORATORIES WOULD BE EXCLUDED ÜCERN COULD REQUIRE TO STICK TO THESE RULES ANYHOW • C 2 H 2 F 4 AND SF 6 CRUCIAL TO ENSURE A STABLE WORKING POINT INAVALANCHE • GWP(C 2 H 2 F 4) = 1430, GWP(SF 6) = 23900, GWP(IC 4 H 10) = 3. 3 • CF 4 (GWP = 5800) USED IN GEMS FOR IMPROVING TIME RESOLUTION: • WE BASED ON THE PHYSICAL AND CHEMICAL PROPERTIES OF THISCOMPONENTS TO: ÜDESIGN FE ELECTRONICS AND CHAMBERS ÜSTUDY PERFORMANCE, AGEING AND CALIBRATION TESTS

A SEARCH FOR POTENTIAL REPLACEMENT • THE STRATEGY: SEARCH A CANDIDATE WITHIN THE GAS USED ASFREON REPLACEMENT IN THE INDUSTRY WITH A LOWERGWP: ndidate a c g in is m o a pr • C 3 H 2 F 4 – TETRAFLUOROPROPENE GWP=4) ( tigated s e v in g in e B • C 2 H 4 F 2 – DIFLUOROETHANEGWP=120) ( • C 2 HF 3 CL 2 (GWP=93), OTHERS … • BARI, FRASCATI AND TOR VERGATA HAVE ALREADY STARTED WORKING ON THIS ISSUE • PERFECT SUBJECT FOR COMMON DEVELOPMENT AND FACILITIES: • FRASCATI AND BARI HAVE WELL EQUIPPED ANDVERSATILE GAS FACILITIES AND ARE GEM CONSTRUCTION FACILITIES • TOR VERGATA HAS AVAILABLE ADVANCED ELECTRONIC TOOLS TO STUDY IN DETAILS THE DETECTOR SIGNAL PHYSICS, DOWN TO 200 ELECTRONS OF NOISE • FOR EACH GAS AND FOREACH MIXTURE : MEASURE ALL THE DETECTOR RESPONSE PARAMETER (TIME, CHARGE SPECTRUM, STREAMER SEPARATION, NOISE, EFFICIENCY) • GIF++ TEST TO MEASURE THE PERFORMANCE, AGEING ANDHF YIELD WG 4 • VERY LONG AND HEAVY R&D , BUT NECESSARY

FIRST RESULTS ON NEW GAS MIXTURES FOR GEMS GEM detectors performance are strictly related to the properties of the gas mixture. An R&D is in progress to find a suitable gas mixture with a small amount of CF 4 Time performance comparison of Ar/CO 2/CF 4 mixtures with a Garfield simulation: • 40/55/5 • 45/15/40 Garfield simulation Experimental results ess ogr n Pr rk I Wo single detector efficiency in 25 ns: • 5% of CF 4 around 80% • 40% of CF 4 around 95% CMS and LHCb GEM groups (RM and LNF) are planning to join competences, tools and test stands to study in details new mixtures

PRELIMINARY RESULTS ON NEW GAS PROPERTIES (RPCS) Gas mixtures tested: Ar/C 4 H 10/TP 83 -3 -15 with increasing % of SF 6 Preliminary FROM LAST RPC 2014 conference in Beijing üTFP has a strong effect both in quenching and in keeping the charge at low level ümixtures are promising even for avalanche working mode with an appropriate FE Electronics and a dedicated chamber layout üNot yet sufficient for the old chambers A long R&D program is needed to analyze all the proposed gases and variants, first with cosmics, then at GIF Single-gap ATLAS prototype, read on the oscilloscope, average charge vs. efficiency

CONCLUSIONS • ITALY HAD A LEADING ROLE IN LHC DETECTORS TECHNOLOGIES (ESPECIALLY MUONS !) • SEVERAL OF THEM WEREINVENTED OR DEVELOPED BY ITALIAN RESEARCHERS AND INSTITUTES • THIS KNOW HOW IS ASTRATEGIC ASSET OF INFN INTERNATIONALLY ACKNOWLEDGED • HL-LHC PROGRAM TRIGGERED ANEW WAVE OF STUDIES ON NEWER AND OLDER DETECTORS, PUSHING TOWARDNEW GENERATIONS, TO FULFIL THE VERY DEMANDING NEEDS • SEVERAL R&D PROGRAM STARTED SPONTANEOUSLY AMONG ITALIAN GROUPS OF DIFFERENT EXPERIMENTS TO POOL KNOWLEDGE AND SAVE RESOURCES IN A VIRTUOUS WAY • IN THE LAST DECADES THEEFFORT FOR LHC CONCENTRATED NATURALLY THE INTELLECTUAL RESOURCES AROUND THIS PROJECTS SO WE EXPECT ASTRONG DRIVE FOR INNOVATIVE DETECTORS USEFUL NOT JUST FOR THEHL-LHC UPGRADES BUT FOR ANY FUTURE EXPERIMENT

BACKUP 12/26/2021 32

“Synergetic” tests at GIF/GIF++ • COMMON EFFORTS ALREADY STARTED BETWEEN: RPC HPL AND GLASS ALICE, ATLAS AND CMS • “STANDARD” TESTS: 1. MEASURE AND MONITOR CHAMBER AGEING CURRENT MONITORING STABILITY DETAILS IN WG 4 2. RPC RADIATION SENSITIVITY 3. RPC RATE CAPABILITY 4. PERFORMANCE UNDER IRRADIATION • COMPARISON AMONG DIFFERENT FE PROPOSED • PERFORMANCE ASSESSMENT UNDER STRESS • SET-UP FOR HF MEASUREMENTS • FUNCTION OF CHAMBERS PARAMETER, IRRADIATION AND GAS MIXTURE COMPOSITION • RPC CONSOLIDATION (IMPROVED CHAMBERS FOR THE EXISTING SYSTEM) • INFRASTRUCTURE BEING DEVELOPED FOR GIF++AT THE OLD GIF INCLUDING: • DCS AND DAQ (BY ATLAS) • FLUORIDE MEASUREMENT TOOLS (BYCMS) • DEDICATED GAS SYSTEM (BYALICE) • GAS HUMIDIFICATION AND DISTRIBUTION (CERN GAS GROUP) • TEST ON BOTH PROTOTYPES AND PRODUCTION CHAMBERS

The facilities available Frascati üGEM flushed with AR/C 02 70/30 üTiming studies done with cosmic rays üGain studies done with Fe 55 üChamber geometry 3, 1. 5, 2, 1 mm Bari ü 10 x 10 cm 2 detector built and under characterization üGEM 1/1_IV full size prototype built and under characterization Spazio per una foto e qualche riga sul laboratorio di Tor Vergata