Novel gaseous detectors and technology r d
1 / 15

Novel Gaseous Detectors and Technology R&D - PowerPoint PPT Presentation

  • Uploaded on

ECFA meeting muon theme3. Novel Gaseous Detectors and Technology R&D. M. Abbrescia (CMS), P . Iengo (ATLAS), D. Pinci ( LHCb ). General considerations.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Novel Gaseous Detectors and Technology R&D' - galia

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Novel gaseous detectors and technology r d

ECFA meeting muon theme3

NovelGaseousDetectors and TechnologyR&D

M. Abbrescia (CMS), P. Iengo (ATLAS), D. Pinci (LHCb)

General considerations

  • All detectors foreseen for post-LS3 with the aim of restore redundancy or increase coverage should stand a rate capability higher then the present

    • Because installed in high-ηregions

    • From 1 kHz/cm2 5-10 kHz/cm2

RPC rate capability

  • In addition we could be willing to improve also:

    • Time resolution – from o(1 ns)  o(100 ps)

    • Spatial resolution – from o(1 cm)  o(1-0.1 mm)

  • Given requirement on rate capability, choice of the technology will be driven by the physics case:

    • plus robustness, cost, easiness of construction, etc.

  • For instance, o(100 ps) would push us toward RPC multigaps solutions

The technology gas electron multipliers
The technology: Gas Electron Multipliers

Developedby F. Sauli in 1997

Eachfoil (perforatedwithholes) is a 50 µm kaptonwithcoppercoatedsides (5 µm )

Typicalholedimensions: Diameter 70 µm, pitch 140 µm

  • Electron multiplicationtakesplacewhentraversing the holes in the kaptonfoils

  • Manyfoils can be put in cascadetoachieve O(104) multiplicationfactors

  • Maincharacteristics:

  • Excellent rate capability: up to 105/cm2

  • Gas mixture: Ar/CO2/CF4 – notflammable

  • Largeareas ~1 m x 2m with industrial processes (costeffective)

  • Long termoperation in COMPASS, TOTEM and LHCb

Detector performance
Detector performance

  • Verygoodtimeresolution

    • Dependingcritically on the gas mixture

    • Long R&D on gas (and otherissues)

  • Excellentspatialresolution

  • Full efficiency at 104overallgain

A new VFAT3 baFEelectronicsbeingdevopedtofully profit fromallthesecaracteristics

σt=4 ns

Gain = 104

σs = 150 µm

The gem project ge1 1
The GEM project: GE1/1

After LHC LS1 the |η|< 1.6 endcapregionwillbecoveredwith 4 layersofCSCs and RPCs; the |η|>1.6 region (mostcritical) willhaveCSCsonly!

  • Restore redundancy in muon system for robust tracking and triggering

  • Improve L1 and HLT muon momentum resolution to reduce or maintain global muon trigger rate

  • Ensure ~ 100% trigger efficiency in high PU environment

And beyond r d on glass rpc
And beyond…R&D on glass RPC

  • New “low” resisitivity (1010Ωcm) glassusedfor high rate RPC

  • RPC rate capabilitydependslinearly on electroderesistivity

  • Smootherelectrodesurfaces reduces the intrinsicnoise

  • Improvedelectronicscharacterizedbylowerthresholds and higheramplification

  • Single and multi-gapconfigurations under study

Readout pads

(1cm x 1cm)

Mylar layer (50μ)

PCB interconnect

Readout ASIC

(Hardroc2, 1.6mm)

PCB (1.2mm)+ASICs(1.7 mm)

PCB support (polycarbonate)

Gas gap(1.2mm)

Cathode glass (1.1mm)

+ resistivecoating

Mylar (175μ)

Ceramic ball spacer

Glass fiber frame (≈1.2mm)

  • Excellent performance at localizedbeamtests

    • Rate capability ~ 30 kHz/cm2 (multi-gap)

    • Timeresolution 20-30 ps

Needs for new technologies
Needs for new technologies

  • Operationat the HL-LHC willbeverydemanding for the muon detectors

  • Alreadyafter LS2 the present muon spectrometerneeds an upgrade in the innerwheels

    • Degradation of the MDT performance in terms of efficiency and resolution

    • Level1 muon trigger dominated by fakes in the endcap

  • A number of R&D programmes on high-rategaseous detectors have been carried out

    • Small-stripThin Gap Chambers (sTGC)

    • Micromegas (MM)

    • Small Monitored Drift Tube (sMDT)

    • Multi-gapResistive Plate Chambers (mRPC)

Selected for the ATLAS New Small Wheel

  • NSW detector requirements

    • Spatial resolution O(100um) single plane

    • Time resolution <10ns for BC identification

    • Angularresolution 1mrad for trigger decision (vertex pointing)

    • Rate capability > 14kHz/cm2

    • High efficiency (>98%)

    • Goodageing performance

    • Double trackresolution (d ~few mm)

Novel gaseous detectors and technology r d

  • Technologyimprovements:

    • In large detectors, resistive cathode reduces the operating voltage.

    • Go from present TGC resistivity (1 MΩ/cm²) to 100 KΩ/cm² and reduce gap between strips to cathode (transparency prop. to RC).

  • Good performance athigh rate

Detector efficiency vs impact angle

Position resolution vs impact angle


  • ATLAS NSW: first large system based on MM

  • Technologybreakthroug:

    • Resistivestrips for sparkimmunities

    • Construction and operationathigh rate of large-area (few m2) detectors possible

    • Bulk technique replaced by ‘floatingmesh’ configuration

    • Good spatial resolutionalso for inclinedtracksthanks to uTPCoperation mode

Spark protection system

Test with neutron flux 106 Hz/cm2

Non-resistive MM

Resistive MM


Position resolution vs impact angle

ti, xi

Yhalf(2.5 mm)



Novel gaseous detectors and technology r d

  • 15 mm diameter tubes

    • Max drift time 185 ns

    • Occupancyscaleswith max drift time and tube cross section: 6.5% at 3x1034 cm-2s-1

    • Gain loss due to space charge effectscales ~r2

    • Good spatial resolutionindipendent on track incidence angle

    • Standard Al tubes, construction procedureswellunder control to equip large area

Efficiency vs counting rate

Spaceresolution vs distance from the wire



Novel gaseous detectors and technology r d



R d needed