Upload
oceana
View
41
Download
7
Tags:
Embed Size (px)
DESCRIPTION
Instrumentation Frontier Community Meeting – Snowmass Process 2013. GEM Upgrade for CMS F orward M uon S ystem Marcus Hohlmann (an IF-EF liaison for gaseous detectors) Florida Institute of Technology. Argonne National Laboratory - Jan 11, 2013. MOTIVATION & INTRODUCTION. - PowerPoint PPT Presentation
Citation preview
GEM Upgrade GEM Upgrade for for
CMS Forward Muon SystemCMS Forward Muon System
Marcus HohlmannMarcus Hohlmann(an IF-EF liaison for gaseous detectors)(an IF-EF liaison for gaseous detectors)
Florida Institute of TechnologyFlorida Institute of Technology
Argonne National Laboratory - Jan 11, 2013
Instrumentation Frontier Community Meeting – Snowmass Process 2013
MOTIVATION & INTRODUCTIONMOTIVATION & INTRODUCTION
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 2
Premise for CMS GEM upgradePremise for CMS GEM upgrade• CMS was designed with a “hermetic and redundant muon system” –
Joe Incandela, CERN “Higgs Discovery” Event, 7/4/12
• But: CMS currently has the least redundancy in the most challenging muon region, i.e. at |η| > 1.6:
Bakelite RPCs descoped in high-η region (lack of rate capability);
only Cathode Strip Chambers currently present
• Long-term functioning of the muon system into LHC Phase II (beyond Long LHC Shutdown 3) is of vital interest for CMS. Use Phase I to evaluate muon technology for Phase II.
• The high-η muon region in particular will need robust and redundant tracking and triggering at the anticipated increasingly higher muon rates
Additional muon detectors with high spatial and temporal resolution in the high-η endcap region could bring benefits
in triggering, reconstruction, and ID for muons: → GEMs
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 3
CMS GCMS GEM EM EEndcap Chambersndcap ChambersThe currently un-instrumented high- RPC region of the muon endcaps presents an opportunity for instrumentation with a detector technology that could sustain the radiation environment long-term and be suitable for operation at the LHC and its future upgrades into Phase II: GEM Detectors
GE3/1
GE4/1
GE1/1in nose of
first Endcap Yoke
CMS Detector
GE1/1 simulation geometry
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 4
Integration into CMS Integration into CMS Four superchambers in their final positionon endcap yoke
Installation sequence:
A. Conde Garcia Mounting on yoke disk
Superchamber(Two Triple-GEMs)
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 5
Expected Benefits for Reconstruction & TriggerExpected Benefits for Reconstruction & Trigger
M. Maggi (Bari) – GEM Workshop 3
Strip Readout granularity: # GEM strips / # RPC strips (orig. TDR)
Expected gains in momentum resolution at high-pT
Acceptance impact: distribution of 4 muons in H → ZZ → 4µ
Paolo Giacomelli (Bologna) & Markus Klute (MIT) – GEM Workshop 3
1.6<<2.4
for one GEM station
Expected CSC inefficiency at PU=400 due to Cathode LCT - Anode LCT timing mismatching
Staving off looming muon trigger inefficiencies at high-
Simulation
A. Safonov (Texas A&M)
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 6
CONSTRUCTION CONSTRUCTION OF FULL-SIZE GEM PROTOTYPESOF FULL-SIZE GEM PROTOTYPES
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 7
Evolution - GEM foil stretchingEvolution - GEM foil stretchingCurrent state-of-the-art: Self-stretching assembly sans spacers (CERN)
Readout PCB
GEMs
Drift electrode
Tightening the horizontal screws tensions the GEMs& seals gas volume
Detector base pcb
R. De Oliveira, CMS-GEM/RD51Workshops CERN & U. Gent
Allows re-opening of assembled detector for repairs if needed.
only glue joint in assembly
2012
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 8
33rdrd GE1/1 Prototype: GE1/1 Prototype: ““Self-Stretched - Sans SpacerSelf-Stretched - Sans Spacer””
GEM tensioningGEM foil in inner frame assembly
GEM foil with inner & outer frame
Inside of readout board with O-ring sealChamber closed byreadout board with
Panasonic connectorsfor frontend electronics
compact HV divider
Vias for strips sealed w/ kapton
HV noisefilters
-sector with 384 radial
readout strips (12.4 cm long)
base pcb with drift electrode
CERN 2012
No spacers in active volume
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 9
GEM active area: 990 mm (220-445) mm Single-mask technology 1D radial strip read-out with 3 8 128 = 3,072 channels 35 HV sectors 3/1/2/1 mm gap sizes Gas mixtures:
Ar/CO2 (70:30; 90:10)Ar/CO2/CF4 (45:15:40; 60:20:20)
Gas flow ≈ 5 l/h
New self-stretching technique has been applied to the full-size CMS GE1/1 GEMs4 prototypes produced & tested at CERN in 2012
1 prototype to be assembled & tested at Fl. Tech in early 20135-8 new final prototypes to be produced for installation of 4 during first LHC long shutdown (LS1)
Full-size GE1/1 Detector PrototypesFull-size GE1/1 Detector Prototypes
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 10
Rui De Oliveira
As a lot of dust was released when inserting screws into FR4 frames; CERN has replaced FR4 by PEEK for inner frames.
PEEK is one of the best polymers in terms of:-radiation tolerance-mechanical properties-outgassing-chemical resistance
Use O-ring to seal outer frames to drift plane; removes ALL glue joints
Panasonic readout connector
Readout PCB
GEM foilsOuter frame
Inner frameDrift Board
On-foil protection resistors
Next: No Gluing & PEEK frameNext: No Gluing & PEEK frame
Now PEEK
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 11
LHC Long Shutdown 1LHC Long Shutdown 1
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 12
GE1/1
GE1/1
ME1/1
ME1/1
ME2/1
YOKE
GE2/1
P5 CAVERN UXC
Prop
osed
to C
MS
Upg
rade
Man
agem
ent
4 GE1/1 GEM chambers in LS1
CMS
Integration & Installation of 2 GE1/1 superchambers = 4 GE1/1 chambers
Measure in situ:•Rates, Background/Noise, Stability, Uniformity, Efficiency•Spatial resolution
– In actual high-η environment – In actual magnetic field
• Split signal to CSC and participate in CMS muon trigger and reconstruction• Install new pre-production trigger motherboards on chambers that overlap with GEMs• Prove that the electronics design is working and demonstrate in situ that we can operate
CSC TMB with GEM input in various operating regimes• Reduce CSC X-Y ambiguity and ghosts• Once we go back to beam operations, demonstrate the above again, this time measuring
muon trigger rates and efficiency with and without GEMs.
Objective: Participate in CRAFT 2014
Proof ofConcept
GEM DAQ Prototype System for LS1GEM DAQ Prototype System for LS1
P. Aspell
DAQ also with link to newCSC Trigger Mother Board
Gigabit Link Interface Boards
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 13
CURRENT R&D:CURRENT R&D:ZIGZAG STRIP READOUTZIGZAG STRIP READOUT
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 14
Previous Work @ BNLPrevious Work @ BNL
7/24/2012 HEP Division Seminar, ANL - Marcus Hohlmann
-100
-80
-60
-40
-20
0
20
40
60
80
100
3000 3500 4000 4500 5000 5500 6000 6500 7000
Reconstructed Position [µm]P
ositi
on E
rror
[µm
]
Zigzag strips:
• Charge sharing among adjacent strips allows quite sensitive position-interpolation in x-direction
• We are sacrificing the measurement of the 2nd coord. (y) to gain precision in the 1st coord. (x)
• CMS GE x/1 detectors are currently intended for 1D-coordinate measurements, so the zigzag approach is applicable to these detectors
x (measured coordinate)
Previous exp. studies show <100 µm resolution with 2 mm strip pitch is possible:
y
15
Concept:
ava-lanche
BNL
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 15
Zigzag strips vs. straight stripsZigzag strips vs. straight strips
Can reduce # of readout channels(and electronics cost) by 70% of current design
Improve resolution by factor 3-4
Pitch [mm]
Typical Resolution [µm]
Zigzag strips & analog r/o 2.0 80Straight strips & VFAT(current design, short end)
0.6 300
Improvement factor w/ zigzag strips
3.33 3.75
A “figure of merit”: 3.33 × 3.75 = 12.5
~ Potential for order of magnitude improvement over current design
Well worth a try!
&
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 16
R&D: Zigzag strips to reduce readout channel R&D: Zigzag strips to reduce readout channel count while maintaining high spatial resolutioncount while maintaining high spatial resolution
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 17
CA
D D
esign by C. P
ancake, Stony B
rook2 mm 2 mm
55Fe spectrum
Stand. CERN10cm × 10cmTriple-GEM
Gasgain
@ FIT
2012 CMS/RD51 beam test @ SPS2012 CMS/RD51 beam test @ SPS
M. Staib (FIT)
Zigzag Resolution = /2 = 73 µm
looking for hit in 5mm window centered on track
150 GeV/c µ & beams
June 2012
preliminarypreliminary
M. Staib (Fl. Tech)
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 18
Next steps for zigzag r/oNext steps for zigzag r/o• Develop successively larger zigzag strip
readout boards: – 30cm × 30cm (Detector already assembled)– 100cm × 45cm CMS GE1/1– GE2/1 prototype? (1.5-2m long)
• Test performance – Spatial resolution in magnetic field– Timing resolution achievable with analog readout
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 19
THE “BIGGER PICTURE”THE “BIGGER PICTURE”Some thoughts on…
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 20
Problem:• Experiments to face high
rates at LHC (HERA-B)
• Aging encountered in
original Micro-Strip Gas Counters (MSGC’s)
• MPGDs show sizable spark rates
Solution:→ First MPGDs invented: high readout granularities with microstrips and small pads lowering occupancies
→ Move avalanches away from materials (microstrips) towards empty space (hole): Gas Electron Multiplier
→ Distribute gain over several elements: Double-GEMs, Triple-GEMs
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 21
GEM Evolution: Problems & Solution GEM Evolution: Problems & Solution
Problem:• GEM detector size limited
to ~ 40cm × 40cm by alignment of two masks during production
• Detector construction using external stretching of GEM foils and epoxy glue (curing time) slows down assembly
• Spacers eat into GEM detector acceptance
• Rising demand for foils
Solution:→ Develop single-mask production process; allows large-area GEMs (currently up to 1m)→ Devise “self-stretching sans spacer” assembly technique (CMS GEMs)
→ Ditto…
→ Upgrade CERN workshop
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 22
GEM Evolution: Problems & SolutionGEM Evolution: Problems & Solution
NB: ALL solutions so far have basically come from CERN; US by far not a leader!
Problem:• Large-area GEM detectors,
e.g. in muon systems, require large number of electronics channels and big DAQ systems rising cost
• One dimension of chambers limited by width of Cu-Kapton foil base material (~60cm)
• Industrial foil production notoriously problematic (Tech Etch, New Flex)
(Future) Solution:→ Scalable Readout System→ Zigzag strips?→ Frontend electronics with much higher chan. integration (à la KPiX); could we do, say, 4k ch. on a single chip!?→ Work directly with industry? Involve NL’s?
→ Ditto; joint ventures between industry & HEP beyond SBIRs?
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 23
GEM Evolution: Problems & SolutionGEM Evolution: Problems & Solution
Brainstorming for “2020”Brainstorming for “2020”• In a phone meeting, someone asked the important question “Can MPGDs
complement silicon as vertex/tracking detectors in highest-rate environments to save cost?” Electron-Ion Collider detector designs in NP
• Can we automate chamber assembly (use robotics)? Cheaply mass-produce a “standard” large-area GEM detector (akin to the CERN standard 10cm × 10cm GEM detectors used for R&D)?
• Can we marry commercial flexible foil circuits and GEM foil technology? Put cheap surface mount readout electronics directly on r/o strip foil or on a GEM foil? => Save chip bonding, connectors, cables, i.e. cost. (see also Julia Thom’s talk on novel technology in EF sessions)
• Can we make MPGDs much more attractive to commercial applications (medical imaging, homeland security,...) so we can get cheap industrial mass production going?
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 24
Thank you for your time!Thank you for your time!
1/11/2013 GEM Upgrade for CMS Forward Muon System - M. Hohlmann, Snowmass IF meeting, ANL 25