UPDATE ON GEM/DHCAL DEVELOPMENT AT UTA Andy White U.Texas at Arlington (for J.Yu, J.Li, M.Sosebee, S.Habib, V.Kaushik) 9/15/03.
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Presentation on theme: "UPDATE ON GEM/DHCAL DEVELOPMENT AT UTA Andy White U.Texas at Arlington (for J.Yu, J.Li, M.Sosebee, S.Habib, V.Kaushik) 9/15/03."— Presentation transcript:
UPDATE ON GEM/DHCAL DEVELOPMENT AT UTA Andy White U.Texas at Arlington (for J.Yu, J.Li, M.Sosebee, S.Habib, V.Kaushik) 9/15/03
Recent developments Moving to multi-channel prototypes GEM foil production Electronics – prototypes Module design concepts
Double GEM schematic From S.Bachmann et al. CERN-EP/2000-151 Create ionization Multiplication Signal induction
Design for DHCAL using Triple GEM Ground to avoid cross-talk Embeded onboard readout
Multichannel prototype - Next step: a 3 x 3 array of 1 cm 2 pads. - Allows one central pad with neighbors for cross-talk tests. - Use a single layer board for simplicity. - Anode board built, prototype reworked. - First results.
Landau Distribution from Cs 137 Source Signal Amplitude (mV)
Readout electronics for DHCAL/GEM - Single channel electronics for first tests (high gain charge preamp + x10 voltage amp.) - Useful for initial development, but not cost effective for larger scale, multi-channel prototypes.
Readout electronics for DHCAL/GEM - Discussions with Fermilab/PPD (Ray Yarema) - Short-term use of electronics developed for silicon readout. (T.Zimmerman) - 32 channel boards. Now at UTA. - Gain within factor of 3 of present single channel system. - Investigating DHCAL/GEM specific design - Coherence with DHCAL/RPC – VME/daughter?
GEM Foil Production - Original production at CERN – but slow, low volume, manpower intensive and expensive. - Interest in U.S. domestic foil production by LC tracking developers and GEM/DHCAL. - 3M Corporation (Microinterconnect Systems Division), Austin, Texas has tried additive and subtractive approaches. - Foil production on 16 inch wide, 500 feet long roll.
Our Motivation: Micro Pattern Gas Detectors (MPGD) in Particle & Astro-Particle Physics TPC readout for LC (GEM or MICROMEGAS) Tracking device at SLHC or VLHC Low-background applications (e.g. coherent neutrino scattering) & WIMP searches Chicago-Purdue-3M P.S. Barbeau J.I. Collar J. Miyamoto I.P.J. Shipsey + DHCAL/GEM developments + Medical imaging potential + ? GEM Foil Production
3M Microinterconnect Systems Division Reel-to-reel process, rolls of 16”’x16” templates of detachable GEMs in any pattern. Optional processes possible. First batch of 1,980 GEMs recently produced. Low cost per unit! (~2 USD/GEM not counting R&D) Two fabrication techniques (additive, substractive) tested. Single roll of ~1,000 GEMS Reel to reel flex circuit manufacture in clean room conditions hep-ex/0304013 Mass Production is based on a 3M Proprietary Flex Circuit Manufacturing Technique
Subtractive (etching) (similar to CERN made GEMs) Additive Cu added to patterned photo resist on Kapton Two fabrication techniques Subtractive Additive
1. Subtractive: Clean hole structure, microcrystals, a small part of the batch have problems with adhesion of Cu on Kapton 2. Additive: Some holes not perfectly round create hole to hole gain variation, a small part of the batch have problems with adhesion of Cu on Kapton hep-ex/0304013 Cu microcrystal Additive method needs improvement to be useful 3M Process Quality
Chicago Purdue 3M GEM SEM Courtesy Fabio Sauli Subtractive 3M Mass Produced GEM
Chicago Purdue 3M GEM SEM Courtesy Fabio Sauli Hole Profile
GEM Performance Typical 55 Fe spectrum uncolllimated source. Ar + 5% CH4 Lower GEM electrode. E/E = 16% typical energy resolution as good as 14% observed. hep-ex/0304013 So far characterization focused on subtractive GEMs 3M GEM and CERN GEM Have comparable E/E = 16% 3M GEm E/E = 16% CERN GEM E/E = 18% http://gdd.web.cern.ch/GDD/
Ar/DME 9:1 Ar/CO2 7:3 Gain measured on lower GEM electrode Gain measured on PCB below GEM Gains of 5,000 in Ar/CO2 7:3 & Ar/DME 9:1 Gain almost identical to CERN made GEMS in same gas x x CERN GEM * (*) S. Bachmann et al. NIM A479 (2002) 294 Gas Gain hep-ex/0304013 CERN
GEM Foil Production - Latest production 2 x 2 pattern of 10x10 cm 2 foils. - Use for DHCAL small prototypes and module development - 3M can make any pattern within the roll parameters (~$2K for artwork)
TESLA – HCAL Layout Development of module concepts
DHCAL/GEM Module concepts Use half-size modules w.r.t. TESLA design
DHCAL/GEM Module concepts Bottom view Side view End view
DHCAL/GEM Module concepts GEM layer slides into gap between absorber sheets
DHCAL-GEM Layer structure - GEM layer -> 6mm - Electronics layer ~3mm - Absorber thickness 16mm x 40 layers -> ~ 4 interaction lengths for HCAL - 10x10 mm 2 cell size -> ~1.5 x 10 7 channels for DHCAL-GEM
DHCAL/GEM active layer - Exploring using the absorber steel gap to provide active layer rigidity. - Build jig to construct active layer with stretch foil layers, thin side walls. - Test transfer/sliding of non-rigid active layer into steel gap. - Start with available width foils from 3M
Design concept for sensitive layer 3mm ionization layer
CONCLUSIONS Further prototype development Exploring electronics solutions with Fermilab/PPD Availability of U.S. domestic GEM foils Investigating active layer construction techniques