update on gem-based calorimetry for the linear collider
DESCRIPTION
Update on GEM-based Calorimetry for the Linear Collider. White 1/11/03 (for J.Yu, J.Li, M.Sosebee, S.Habib, V.Kaushik). Summary of criteria for GEM-based LC Calorimetry. Thin sensitive/readout layer for compact calorimeter design - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/1.jpg)
Update onGEM-based Calorimetryfor the Linear Collider
A.White 1/11/03(for J.Yu, J.Li, M.Sosebee,
S.Habib, V.Kaushik)
![Page 2: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/2.jpg)
Summary of criteria for GEM-based LC Calorimetry
- Thin sensitive/readout layer for compact calorimeter design- Simple 1- or 2-level “hit” recording for energy flow algorithm use- On-board amplification/digitization/discrimination for digital readout – noise/cross-talk minimization- Flexible design for easy implementation of arbitrary “cell” size
![Page 3: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/3.jpg)
- Modular design with easy module-to-module continuity for supplies, readout path- Digital readout from each cell- Pad design (to avoid x-y strip complications)- small cell size for good two/multiple track separation- high efficiency for MIPs in a cell- option for multiple thresholds
Criteria continued…
![Page 4: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/4.jpg)
Design for DHCAL using Triple GEM
Ground to avoid cross-talk
Embeded onboard readout
![Page 5: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/5.jpg)
UTA Approach to GEM/Calorimetry
Two-prong approach - Simulate, in detail, stack of GEM hadron calorimetry (see V.Kaushik’s talk) - Develop practical experience assembling a GEM foil based detector from scratch.
![Page 6: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/6.jpg)
From CERN-open-2000-344, A. Sharma
![Page 7: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/7.jpg)
From CERN GDD group
GEM gains
![Page 8: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/8.jpg)
Double GEM schematic
From S.Bachmann et al. CERN-EP/2000-151
![Page 9: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/9.jpg)
Areas of GEM related study GEM foil handling, testing, installation. GEM double layer structure design and implementation. HV distribution system design implementation. GEM anode pad design, variations, testing. Readout electronics trials Complete prototype assembly, testing.
![Page 10: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/10.jpg)
GEM prototype assembly
![Page 11: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/11.jpg)
![Page 12: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/12.jpg)
![Page 13: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/13.jpg)
![Page 14: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/14.jpg)
GEM FOILS (testing)- Foils for prototype purchased from GDD group at CERN ($400 each – framed)- Initial experience: foils are fairly robust; we have so far only exposed them in clean room environment; care with human exposure!- Electrical testing: first test – HVPS with A meter -> discharge -> local damage to ~5 holes -> fix with copper etch locally.- nA level current monitoring -> easily reach 450V across foils in air – repeatable.
![Page 15: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/15.jpg)
GEM FOILS (production)- Calorimeter and tracking groups in U.S. interested in GEM-based detectors.- Clearly U.S. source would be preferable.- Potential sources: 3M Thin Films, MIT ?, Louisiana Tech.?- Issues: - etching vs. micro-machining etc.? - only limited quantities needed for HEP - interest from medical imaging ? - hole size, shape, quality for HEP use?
![Page 16: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/16.jpg)
Micrograph of GEM foil
From CERN GDD Group
![Page 17: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/17.jpg)
Defects in chemically etched GEM foils, showing misshaped and missing holes. Taken from F. Fraga et al. NIM A442, 417, 2000
GEM foil issues
![Page 18: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/18.jpg)
Detail of GEM foil hole
From CERN GDD Group
![Page 19: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/19.jpg)
GEM amplification vs. metal hole size
from A. Sharma CERN OPEN-98-030
![Page 20: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/20.jpg)
GEM test chamber ( J.Li, UTA )
![Page 21: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/21.jpg)
GEM/MIP signal size- Double GEM ~2100V -> ~ Gain 3000- Ionization ~30 i.p./cm => 10 e- / MIP- This gives ~ 30,000 e- on an anode pad.- 30,000 e- = 5 fC- GEM signal timing ~20ns- Current 5fC/20ns = 0.25 A- Amplifier sensitivity 25 mV/A- Expect signals ~5mV for MIP through GEM
![Page 22: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/22.jpg)
![Page 23: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/23.jpg)
![Page 24: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/24.jpg)
![Page 25: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/25.jpg)
![Page 26: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/26.jpg)
Anode pad
layout
![Page 27: Update on GEM-based Calorimetry for the Linear Collider](https://reader033.vdocument.in/reader033/viewer/2022051518/56815d37550346895dcb3928/html5/thumbnails/27.jpg)
GEM Prototype Status- GEM chamber assembled/re-assembled several times to optimize layer spacing, HV stability, ...- Initially large noise problems (from building) – now mainly suppressed through grounding, filtering, sheilding.- Testing 1) Cosmic rate is 0.1 Hz through ~6 cm2 pad 2) Source Cs-137 e- ~1 MeV vs. GEM board
- See signals … not yet uniquely attributable to GEM.