SLIDE 0 TITLE Fabio SAULI INFN-Trieste and TERA Foundation CERN-Geneva-Switzerland

SLIDE 1 MSGC THE ANCESTOR THE MICRO-STRIP GAS CHAMBER MSGC: POSITION ACCURACY ~ 50 µm TWO-TRACK RESOLUTION ~ 500 µm RATE CAPABILITY ~ 1 MHz/mm 2 BUT: TOO FRAGILE EASILY DAMAGED BY DISCHARGES ANODE CATHODE 200 µm A. Oed, Nucl. Instr. Meth. A263(1988)351 MICRO-PATTERN GAS DETECTORS:

SLIDE 2 THIN METAL-COATED POLYMER FOIL CHEMICALLY ETCHED ~ HOLES mm 2 TYPICAL GEM: 50 µm Kapton 5 µm Copper 70 µm holes at 140 µm pitch F. Sauli, Nucl. Instr. and Meth. A386(1997) ,000 INDEPENDENT PROPORTIONAL COUNTERS per cm 2 ! GEM PRINCIPLE GAS ELECTRON MULTIPLIER (GEM):

SLIDE 3 GEM MANUFACTURING GEM MANUFACTURING (CERN PROCESS) 50 µm Kapton +5 µm Cu both sides Photoresist coating, masking, exposure to UV light Metal etching Kapton etching Second masking Edge metal etching and cleaning 70 µm 55 µm

SLIDE 4 LARGE GEM FOIL FOR COMPASS: GEM SHAPES “STANDARD” GEM: 10x10 cm 2 MAGNETIC SPECTROMETER (OSAKA UIV.) 10 cm 1500÷2000 FOILS MADE 1 cm 2 to 2000 cm µm HOLES, µm PITCH GEM PRODUCTION AT CERN

SLIDE 5 HALF-MOON GEM FOR TOTEM: GEM SHAPES ROUND GEM (30 cm Ø ) ESA PROTOTYPE FLEXIBILITY OF SHAPE

SLIDE 6 1-D STRIPS READOUT PATTERNS 2-D STRIPS PADS PAD ROWS COICE OF ANODE READOUT PATTERNS Tokyo Univ. CNS CERN

SLIDE 7 GEM DETECTORS PERFORMANCE 5.9 keV 55 Fe : 20% FWHM SINGLE GEM PERFORMANCES ENERGY RESOLUTION R. Bouclier et al Nucl. Instr. and Meth. A 396 (1997) 50 GAIN VS VOLTAGE:

SLIDE 8 CASCADED GEMS PROVIDE HIGHER GAIN AT LOWER VOLTAGE DRIFT INDUCTION C. Büttner et al, Nucl. Instr. and Meth. A409(1998)79 S. Bachmann et al, Nucl. Instr. and Meth. A438(1999)376 MULTIGEM MULTIGEM DETECTORS DISCHARGE PROBABILITY ON 5 MeV  (FROM 220 Rn)  E ~ 1 MeV/cm

SLIDE 9 J. Benlloch et al, IEEE NS-45(1998) Hz mm -2 VERY HIGH RATE CAPABILITY M. Alfonsi et al, Nucl. Instr. and Meth. A518(2004) mC mm -2 ~ mips mm -2 RADIATION HARDNESS (AGING): GEM HIGH RATE

SLIDE TRIPLE-GEM CHAMBERS, 31x31 cm 2 ACTIVE 2-D CHARGE READOUT Honeycomb plates GEM foils 2-D Readout board LIGHT CONSTRUCTION: ~ 0.7% X 0 B. Ketzer et al, Nucl. Instr. and Meth. A535(2004)314 COMPASS CHAMBERS GEM DETECTOR FOR COMPASS

SLIDE 11 COMPAS TGEM 31x31 cm 2, 12-SECTORS+BEAM KILLER ~ 100 FOILS PRODUCED AT CERN Sector separation Voltage-controlled Central disk C. Altumbas et al, Nucl. Instr. and Meth. A 490(2002)177

SLIDE 12 COMPASS RESULTS COMPASS CHAMBERS PERFORMANCES UNIFORMITY OF EFFICIENCY: ~ 97% FOR MINIMUM IONIZING TRACKS, HIGH INTENSITY RUNS (2.5x10 4 Hz mm -2 ) POSITION ACCURACY 65 µm rms TIME RESOLUTION B. Ketzer et al, Nucl. Instr. and Metrh. A535(2004) ns rms

SLIDE 13 COMPASS TRIPLE-GEM: PSI πM1 beam No discharges in 12 hrs of operation at gain 10 4 (+ 4 years of operation in COMPASS!) S. Bachmann et al, Nucl. Instr. and Meth. GAIN 10 4 DISCHARGE PROBABILITY < (DISCHARGES PER INCIDENT PARTICLE) DISCHARGES DISCHARGE PROBABILITY G=10000

SLIDE 14 TIME RESOLUTION USING A FASTER GAS (LHCb MUON TRIGGER) TIME RESOLUTION M. Alfonsi et al, Nucl. Instr. and Meth. A535(2004)319 INTRINSIC TIME RESOLUTION: 4-GEM with reflective photocathode (isochronous electrons): D. Mormann et al, Nucl. Instr. and Meth. 504(2003)93 Ar-CO 2 -CF 4 ( )

SLIDE 15 HALF-MOON SHAPED TRIPLE-GEM TOTEM GEM GEM DETECTOR FOR TOTEM CERN-HELSINKI) L. Ropelewski, Vienna Instrumentation Conf READOUT: VFAT 128-CHANNELS DIGITAL READOUT WITH FAST OR 10-CHAMBERS BEAM SETUP:

SLIDE 16 TOTEM CHAMBERS TOTEM TRIPLE-GEM CHAMBERS FRAMED GEM: READOUT BOARD:

SLIDE 17 TOTEM READOUT 50  m Polyimide 25  m Polyimide 125  m FR4 15  m Cu Epoxy glue 5  m Cu 10  m Cu Epoxy glue Ni Au 15  m Cu TOTEM Readout radial stripspads bonding contact for pads READOUT BOARD: Radial strips (accurate track’s angle) Pad matrix (fast trigger) TOTEM CHAMBERS READOUT: PADS AND STRIPS 5-LAYERS PC BOARD READOUT: VFAT 128-CHANNELS DIGITAL READOUT WITH FAST OR

SLIDE 18 TEST RESULTS LABORATORY TEST CHARGE SHARING ON 55 Fe SOURCE: BEAM TEST TWO-CHAMBERS CORRELATION TOTEM CHAMBERS TEST RESULTS L. Ropelewski, Vienna Instr. Conf. (Feb 07)

SLIDE 19 THIN CHAMBERS PIXEL AND STRIPS GEM CHAMBER (COMPASS UPGRADE) READOUT ELECTRODE: CENTER: 32x32 PIXELS, 1 mm 2 EACH SIDES: 512x512 STRIPS, 400 µm PITCH THIN TRIPLE GEM CHAMBERS : 0.2 % X 0 F. Haas et al, Vienna Instr. Conf (Feb. 2007)

SLIDE 20 QUALITY CONTROL DEVELOPMENT OF SEMI-AUTOMATIC SYSTEMS HOLE FITTING DIGITAL IMAGE ANALYSIS T. Hilden, Helsinki QUALITY CONTROL

SLIDE 21 QUALITY CONTROL HOLE’S DIAMETER DISTRIBUTION AND DEFECTS IDENTIFICATION T. Hilden, Helsinki

SLIDE 22 GEM TPC TPC MPGD FAST ELECTRON SIGNAL  T~20 ns (-> ~ 1mm) NARROW PAD RESPONSE  s ~ 1 mm VERY GOOD MULTI-TRACK RESOLUTION  V ~ 1 mm 3 STRONG ION FEEDBACK SUPPRESSION I + /I - < 0.1% NO ExB DISTORTIONS FREEDOM IN END-CAP DESIGN ROBUST, RADIATION HARD PADS INFLATION! MPGD READOUT OF TIME PROJECTION CHAMBERS

SLIDE 23 LEGS (LASER ELECTRON GAMMA SOURCE) AT BNL: Bo Yu, LBL TPC Workshop (Berkeley 7-8 April 2006) COSMIC TRACKS: GEM-TPC FOR LEGS

SLIDE 24 MICRO-PIXEL TPC COMPTON CAMERA WITH µTPC + SCINTILLATORS TO AVOID DISCHARGES: ADDED GEM FOIL K. Hattori et al, Vienna Instr. Conf. (Feb. 2007) MICRO-PIXEL TPC COSMIC TRACKS

SLIDE 25 T2K READOUT: 8x8 mm 2 PAD PLANE GEM TPC PROTOTYPE FOR T2K HARP TPC WITH TRIPLE GEM END CAP E. Radicioni, IEEE Nucl. Sci. Symp. San Diego (Oct. 2006)

SLIDE 26 M. Killenberg et al, Nucl. Instr. Meth. A530(2004)251 POSITION RESOLUTION: GEM TPC (DESY-AACHEN) M. Janssen et al, Nucl. Instr. Meth. A566(2006)75 GEM TPC DESY AACHEN GEM-TPC: MPGD TPC FOR THE INTERNATIONAL LINEAR COLLIDER 130 µm

SLIDE 27 KEK MPGD TPC GEM-MICROMEGAS TPC STUDYES AT KEK Detection plane Preamplifiers Bulkhead Field cage Drift electrode M. Kobayashi, Vienna Instrum. Conf. (Feb. 2007) JECCEE MAGNET 85 cm Ø 1 m LONG

SLIDE 28 PAD DILEMMA SMALL TRANSVERSE DIFFUSION GIVES BETTER ACCURACY BUT REQUIRES SMALL PAD SIZE FOR CHARGE SHARING Computed with Steve Biagi’s MAGBOLTZ MULTIGEM: INCREASED DIFFUSION IN TRANSFER REGIONS DRIFT TRANSFER MICROMEGAS: DRIFT DIFFUSION ONLY FOR 1 m DRIFT FWHM ~ 1.4 mm FOR 1 m DRIFT FWHM ~ 1 mm THE TPC DILEMMA

SLIDE 29 OPTIMIZATION OF PAD GEOMETRY OPTIMIZATION OF READOUT PAD GEOMETRY J. Kaminski, LBL TPC Workshop (Berkeley 7-8 April 2006) TWO-TRACK RESOLUTION STUDIES WITH LASER BEAMS (Victoria-DESY)

SLIDE 30 FOR PAD SIZE ~ 1 mm PAD DILEMMA MULTIGEM STRUCTURES BETTER AT SHORT DRIFT DISTANCE, BECAUSE OF ADDITIONAL AVALANCHE SPREAD M. Kobayashi, Vienna Instr. Conf. (2007) MEASUREMENTS AND SIMULATIONS MicroMEGAS GAS: Ar-isobutane E = 220 V/cm B = 1 T DRIFT DISTANCE (mm) RESOLUTION (mm) GEM GAS: P5 E = 100 V/cm B = 1 T DRIFT DISTANCE (mm) RESOLUTION (mm) PAD PITCH DIFFUSION STUDIES OF OPTIMUM PAD SIZE KEK

SLIDE 31 CHARGE SPREAD RESISTIVE ANODE READOUT: RC CHARGE SPREAD resistive foil glue pads PCB mesh MEASURED 5 TESLA MICROMEGAS WITH RESISTIVE ANODE: OPEN QUESTIONS: - UNIFORMITY OF RESISTIVITY - RATE CAPABILITY - LOSS IN TWO-TRACK RESOLUTION

SLIDE 32 CF4 GAS IMPROVING TPC PERFORMANCES Computed with MAGBOLTZ - VERY LOW DIFFUSION - NON FLAMMABLE - HYDROGEN FREE (LOW NEUTRON CROSS SECTION) CF 4 :

SLIDE 33 CF4 GAS CF 4 Ar-C 2 H 8 Ar-CH 4 GEM-TPC OPERATION IN CF4 (H=0) S.X. Oda et al, Nucl. Instr. Methods A566(2006)312 ~100 µm ACCURACY WITHOUT MAGNETIC FIELD! GAIN COMPARISON FOR A TRIPLE GEM : (Tokyo Univ. CNS, ……)

SLIDE 34 CHARGING UP GEM CHARGING-UP SMALL, RATE-DEPENDENT INITIAL GAIN INCREASE (~30%): SCHEMATICS OF DOUBLE- CONICAL GEM CHARGING UP: BEFORE AFTER HIGHER FIELD->HIGHER GAIN C. Altumbas et al, Nucl. Instr. and Meth. A490(2002)177

SLIDE 35 CHARGING UP GAIN INCREASE IS VOLTAGE INDEPENDENT: POLARIZATION? DOTS: MEASURED GAIN FIT TO DATA ASSUMING GAIN (TGEM)= GAIN 3 (SGEM) 8 keV X-RAYS FOR EQUAL GAIN (~10 3 ): HV(SGEM)=510 V HV(TGEM)=3x310 V G. Croci, L. Rolpelewski, F. Sauli (2007) CHARGING UP: STANDARD SINGLE AND TRIPLE GEM

SLIDE 36 CHARGING-HOLE SHAPE SPECIAL TRIPLE ETCH: SINGLE, DOUBLE AND TRIPLE POLYMER ETCHING: CHARGING UP VS HOLE SHAPE G. Croci, L. Rolpelewski, F. Sauli (2007) STANDARD SINGLE ETCH: GAIN SHIFT: SUM OF TWO EFFECTS: POLARIZATION (INCREASE) CHARGING (DEPENDS ON HOLE SHAPE)

SLIDE 37 LASER ETCH LASER-ETCHED GEMS (RIKEN) T. Tamagawa et al, Nucl. Instr. Meth. A560(06)418 NO CHARGING UP:

SLIDE 38 CYLINDRICAL GEM E. David, M. Van Stenis, L. Ropelewski, F. Sauli (CERN - DT2) CYLINDRICAL GEM DETECTORS - CERN DEVELOPMENT

SLIDE 39 CYLINDRICAL GEM (NA49 UPGRADE) 2-D STRIP READOUT L. Ropelewski, Vienna Instr. Conf LOW MASS PROTOTYPE FOR CHLOE (FRASCATI): G. Bencivenni et al, Vienna Instr. Conf CYLINDRICAL GEM DETECTORS

SLIDE 40 BONUS 3200 PIXELS READOUT H. Fenker, IEEE Nucl. Sci. Symp (Puerto Rico, 2005) EVENT DISPLAY: RADIAL GEM TPC FOR BoNuS (JLAB)

SLIDE 41 E DRIFT ~ 0 UV PHOTON DETECTION WITH GEM R. Bouclier et al, IEEE Trans. Nucl. Science NS-44(1997)646 REFLECTIVE CsI PHOTOCAHODE SINGLE PHOTOELECTRON POSITION ACCURACY CsI-COATED TRIPLE GEM Center of gravity distribution for two UV beams, 200 µm apart: T. Meinschad et al, Nucl. Instr. and Meth. A535(2004)324  = 55 µm e FURTHER MULTIPLICATION PHOTON DETECTION

SLIDE 42 HEXAGONAL PADS PLANE, 500 µm PITCH U V W PAD ROWS INTERCONNECTED ALONG THREE DIRECTIONS: 1.1 mm 2.4 mm 1.3 mm T. Meinschad et al, Nucl. Instr. and Meth. A535(2004)324 FAST RICH ( 2 ns resolution) DOUBLE PHOTON EVENT: HEXABOARD HEXABOARD PAD READOUT

SLIDE 43 PHENIX UPGRADE - HADRON BLIND DETECTOR e+e+ e-e- E Hadrons 24 TGEM DETECTORS WITH PAD READOUT I. Ravinovich, Quark Matter 2005 A. Kozlov et al, Nucl. Instr. and Meth.A523(2004)344 WINDOWLESS CHERENKOV COUNTER CsI-COATED GEM DETECTOR CF 4 RADIATOR HADRON BLIND

SLIDE 44 electrons hadrons PULSE HEIGHT: C. Woody et al., 2006 IEEE NSS/MIC Proceedings Z. Fraenkel et al, NIMA 546(2005) 466 HADRON BLIND ELECTRON-HADRON DISCRIMINATION: PHENIX HADRON BLIND DETECTOR

SLIDE 45 TIMEPIX 3xGEM TIMEPIX: 256x256 PIXELS 55 µm x 55 µm TIMEPIX GEM GEM DIFFUSION SPREAD: CLUSTER COUNTING THE ULTIMATE MPGD: INTEGRATED PIXEL ELECTRONICS READOUT M. Titov, Vienna Insr. Conf. (Feb. 2007) 3 pixel functionality modes 14 mm 600  m 14 mm VERY GOOD 2-TRACK RESOLUTION

SLIDE 46 R. Bellazzini et al, Nucl. Instr. and Methods A435(2004)477 15x15 mm 2 ACTIVE, ~ 100 kPIXELS (470 PIXELS/mm 2 ) POLARIMETER DEDICATED CMOS PIXEL READOUT CIRCUIT

SLIDE 47 MEASURE THE AVERAGE POLARIZATION OF SOFT X-RAYS POLARIMETER R.Bellazzini et al, Nucl. Instr. Methods A572(2007) mm 2 ANGULAR DISTRIBUTION FOR POLARIZED SOFT X-RAYS: GEM POLARIMETER

SLIDE 48 GEM IMAGER PHOTON IMAGER UV FLOODLIGHT CsI on QUARTZ WINDOW FINE PITCH GEM 30 µm 50 µm PITCH CMOS PIXEL READOUT 4 µm rms R. Bellazzini et al, Vienna Instr. Conf (Feb. 2007)

SLIDE 49 CRIOGENIC CRYOGENIC DETECTORS A. Bondar et al, Nucl. Instr. Meth. A 556(2005)273 ) TWO-PHASE DETECTOR: ELECTRONS EXTRACTION AND MULTIPLICATION He, 4.2 K A. Buzulutskov et al, Nucl. Instr. Meth. A548(2005)487 LOW TEMPERATURE GEM OPERATION: GAS MPGD LIQUID

SLIDE 50 CRIOGENIC P. K. Lightfoot, Nucl. Instr. Meth. A554(2005)266 TWO-PHASE XENON DETECTOR FOR DARK MATTER SEARCH GAIN CHARACTERISTICS LXe (171 º K)+2% CH 4 µM+GEM µM CsI-COATED GEM FOR PHOTONS CONVERSION MICROMEGAS DETECTOR L-Xe SENSITIVE VOLUME

SLIDE 51 RATE CAPABILITY: > 3 MHz mm -2 TIME RESOLUTION: 5÷10 ns FOR PARTICLES, ~ 1 ns FOR PHOTONS LOCALIZATION ACCURACY: 60 µm IN EXPERIMENTS, ~5 µm IN LABORATORY PROPORTIONAL GAIN > 10 5 (SINGLE PHOTOELECTRON DETECTION) RADIATION HARDNESS: > MIPS cm -2 (INERT WITH HV OFF) ARBITRARY SHAPES AND READOUT PATTERN (STRIPS, PADS,…) NON-PLANAR GEOMETRY LARGE AREAS AT LOW COST: ~ 2000 cm 2 SUMMARY FUTURE IMPROVEMENTS: MAIN PERFORMANCES: LARGER AREAS ( ~ 1 m 2 ), ALTERNATIVE SOURCE IMPROVED QUALITY CONTROL IMPROVED MEDIUM- AND LONG-TERM STABILITY (CHARGING UP PROBLEMS) DEVELOPMENT OF DEDICATED, HIGH DENSITY READOUT ELECTRONICS MICROPATTERN GAS DETECTORS SUMMARY

SLIDE 52 THANKS