SLIDE 1TITLE

Fabio SAULI

INFN-Trieste and TERA Foundation

CERN-Geneva-Switzerland

SLIDE 2MSGC

THE ANCESTOR THE MICRO-STRIP GAS CHAMBER

MSGC: POSITION ACCURACY ~ 50 µm TWO-TRACK RESOLUTION ~ 500 µm RATE CAPABILITY ~ 1 MHz/mm2

BUT: TOO FRAGILE EASILY DAMAGED BY DISCHARGES

ANODE CATHODE CATHODE

200 µm

A. Oed, Nucl. Instr. Meth. A263(1988)351

MICRO-PATTERN GAS DETECTORS:

SLIDE 3

THIN METAL-COATED POLYMER FOIL CHEMICALLY ETCHED~ 50-100 HOLES mm2

TYPICAL GEM: 50 µm Kapton 5 µm Copper 70 µm holes at 140 µm pitch

F. Sauli, Nucl. Instr. and Meth. A386(1997)531

5-10,000 INDEPENDENT PROPORTIONAL COUNTERS per cm2!

GEM PRINCIPLEGAS ELECTRON MULTIPLIER (GEM):

SLIDE 4GEM 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 5

LARGE GEM FOIL FOR COMPASS:

GEM SHAPES

“STANDARD” GEM: 10x10 cm2

MAGNETIC SPECTROMETER (OSAKA UIV.)

10 cm

1500÷2000 FOILS MADE1 cm2 to 2000 cm2

30-200 µm HOLES, 50-300 µm PITCH

GEM PRODUCTION AT CERN

SLIDE 6

HALF-MOON GEM FOR TOTEM:

GEM SHAPES

ROUND GEM (30 cm Ø ) ESA PROTOTYPE

FLEXIBILITY OF SHAPE

SLIDE 7

1-D STRIPS

READOUT PATTERNS

2-D STRIPS

PADS

PAD ROWS

COICE OF ANODE READOUT PATTERNS

Tokyo Univ. CNS

CERN

SLIDE 8GEM DETECTORS PERFORMANCE

5.9 keV 55Fe : 20% FWHM

SINGLE GEM PERFORMANCES

ENERGY RESOLUTION

102

103

104

200 300 400 500 600 700VGEM

(V)

SINGLE GEM+PCB

Eff. Gain-Vgem Ar-CO2-DME

Ar-DME 70-30

Ar-CO2 70-30

Effe

ctiv

e G

ain

R. Bouclier et al Nucl. Instr. and Meth. A 396 (1997) 50

GAIN VS VOLTAGE:

SLIDE 9

CASCADED GEMS PROVIDE HIGHER GAIN AT LOWER VOLTAGE

DRIFT

INDUCTION

C. Büttner et al, Nucl. Instr. and Meth. A409(1998)79S. Bachmann et al, Nucl. Instr. and Meth. A438(1999)376

MULTIGEMMULTIGEM DETECTORS

DISCHARGE PROBABILITY ON 5 MeV (FROM 220Rn) E ~ 1 MeV/cm

SLIDE 10

J. Benlloch et al, IEEE NS-45(1998)234

3.106 Hz mm-2

VERY HIGH RATE CAPABILITY

M. Alfonsi et al, Nucl. Instr. and Meth. A518(2004)106

200 mC mm-2 ~ 4 •1012 mips mm-2

RADIATION HARDNESS (AGING):

GEM HIGH RATE

SLIDE 11

22 TRIPLE-GEM CHAMBERS, 31x31 cm2 ACTIVE 2-D CHARGE READOUT

Honeycomb plates

GEM foils

2-D Readout board

LIGHT CONSTRUCTION: ~ 0.7% X0

B. Ketzer et al, Nucl. Instr. and Meth. A535(2004)314

COMPASS CHAMBERSGEM DETECTOR FOR COMPASS

SLIDE 12COMPAS TGEM

31x31 cm2, 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 13COMPASS RESULTS COMPASS CHAMBERS PERFORMANCES

UNIFORMITY OF EFFICIENCY: ~ 97% FOR MINIMUM IONIZING TRACKS, HIGH INTENSITY RUNS (2.5x104 Hz mm-2)

POSITION ACCURACY

65 µm rms

TIME RESOLUTION

B. Ketzer et al, Nucl. Instr. and Metrh. A535(2004)314

12 ns rms

SLIDE 14

COMPASS TRIPLE-GEM: PSI πM1 beamNo discharges in 12 hrs of operation at gain 104 (+ 4 years of operation in COMPASS!)

S. Bachmann et al, Nucl. Instr. and Meth. A470(2001)548

@ GAIN 104

DISCHARGE PROBABILITY < 10-12

(DISCHARGES PER INCIDENT PARTICLE)

DISCHARGESDISCHARGE PROBABILITY

G=10000

SLIDE 15TIME 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-CO2-CF4 (45-15-40)

SLIDE 16

HALF-MOON SHAPED TRIPLE-GEM

TOTEM GEMGEM DETECTOR FOR TOTEMCERN-HELSINKI)

L. Ropelewski, Vienna Instrumentation Conf. 2007

READOUT: VFAT 128-CHANNELSDIGITAL READOUT WITH FAST OR

10-CHAMBERS BEAM SETUP:

SLIDE 17TOTEM CHAMBERS TOTEM TRIPLE-GEM CHAMBERS

FRAMED GEM:

READOUT BOARD:

SLIDE 18TOTEM READOUT

50 m Polyimide

25 m Polyimide

125 m FR4

15 m CuEpoxy glue

5 m Cu10 m CuEpoxy glue

Ni Au15 m Cu

TOTEM Readout

radial stripspads bonding contactfor 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-CHANNELSDIGITAL READOUT WITH FAST OR

SLIDE 19TEST RESULTS

LABORATORY TESTCHARGE SHARING ON 55Fe SOURCE:

BEAM TESTTWO-CHAMBERS CORRELATION

TOTEM CHAMBERS TEST RESULTS

L. Ropelewski, Vienna Instr. Conf. (Feb 07)

SLIDE 20THIN CHAMBERS PIXEL AND STRIPS GEM CHAMBER (COMPASS UPGRADE)

READOUT ELECTRODE: CENTER: 32x32 PIXELS, 1 mm2 EACHSIDES: 512x512 STRIPS, 400 µm PITCH

THIN TRIPLE GEM CHAMBERS :0.2 % X0

F. Haas et al, Vienna Instr. Conf (Feb. 2007)

SLIDE 21QUALITY CONTROL

DEVELOPMENT OF SEMI-AUTOMATIC SYSTEMS

HOLE FITTING HOLE FITTING

DIGITAL IMAGE ANALYSIS

T. Hilden, Helsinki

QUALITY CONTROL

SLIDE 22QUALITY CONTROL HOLE’S DIAMETER DISTRIBUTION AND DEFECTS IDENTIFICATION

T. Hilden, Helsinki

SLIDE 23

GEM TPC

TPC MPGD

FAST ELECTRON SIGNAL T~20 ns (-> ~ 1mm)

NARROW PAD RESPONSE s ~ 1 mm

VERY GOOD MULTI-TRACK RESOLUTION V ~ 1 mm3

STRONG ION FEEDBACK SUPPRESSION I+/I- < 0.1%

NO ExB DISTORTIONSFREEDOM IN END-CAP DESIGNROBUST, RADIATION HARD

PADS INFLATION!

MPGD READOUT OF TIME PROJECTION CHAMBERS

SLIDE 24LEGS

(LASER ELECTRON GAMMA SOURCE) AT BNL:

Bo Yu, LBL TPC Workshop (Berkeley 7-8 April 2006)

COSMIC TRACKS: COSMIC TRACKS:

GEM-TPC FOR LEGS

SLIDE 25MICRO-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 26T2K

READOUT: 8x8 mm2 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 27

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 28KEK MPGD TPCGEM-MICROMEGAS TPC STUDYES AT KEK

Detection plane

Preamplifiers

Bulkhead

Field cage

Driftelectrode

M. Kobayashi, Vienna Instrum. Conf. (Feb. 2007)

JECCEE MAGNET 85 cm Ø 1 m LONG

SLIDE 29PAD DILEMMA

SMALL TRANSVERSE DIFFUSION GIVES BETTER ACCURACYBUT 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 DRIFTFWHM ~ 1.4 mm

FOR 1 m DRIFTFWHM ~ 1 mm

THE TPC DILEMMA

SLIDE 30OPTIMIZATION 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 31

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)

RE

SO

LU

TIO

N (

mm

)

0 300 0

0.8

GEM GAS: P5 E = 100 V/cm B = 1 T

DRIFT DISTANCE (mm)

RE

SO

LU

TIO

N (

mm

) 0 300

0.4

0

PAD PITCH DIFFUSION

STUDIES OF OPTIMUM PAD SIZE

KEK

SLIDE 32CHARGE SPREADRESISTIVE ANODE READOUT: RC CHARGE SPREAD

resistive foilgluepads

PCB

mesh

MEASURED RESOLUTION @ 5 TESLA MICROMEGAS WITH RESISTIVE ANODE:

OPEN QUESTIONS:- UNIFORMITY OF RESISTIVITY- RATE CAPABILITY- LOSS IN TWO-TRACK RESOLUTION

SLIDE 33CF4 GAS

IMPROVING TPC PERFORMANCES

Computed with MAGBOLTZ

- VERY LOW DIFFUSION- NON FLAMMABLE- HYDROGEN FREE (LOW NEUTRON CROSS SECTION)

CF4 :

SLIDE 34CF4 GAS

CFCF44

Ar-C2H8

Ar-CH4

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 35CHARGING UPGEM 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 36CHARGING UP

GAIN INCREASE IS VOLTAGE INDEPENDENT:POLARIZATION?

DOTS: MEASURED GAINFIT TO DATA ASSUMING GAIN (TGEM)= GAIN3(SGEM)

8 keV X-RAYS

FOR EQUAL GAIN (~103): HV(SGEM)=510 V HV(TGEM)=3x310 V

G. Croci, L. Rolpelewski, F. Sauli (2007)

CHARGING UP: STANDARD SINGLE AND TRIPLE GEM

SLIDE 37CHARGING-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 38LASER ETCH

LASER-ETCHED GEMS (RIKEN)

T. Tamagawa et al, Nucl. Instr. Meth. A560(06)418

NO CHARGING UP:

SLIDE 39CYLINDRICAL GEM

E. David, M. Van Stenis, L. Ropelewski, F. Sauli (CERN - DT2)

CYLINDRICAL GEM DETECTORS - CERN DEVELOPMENT

SLIDE 40CYLINDRICAL GEM

(NA49 UPGRADE)2-D STRIP READOUT

L. Ropelewski, Vienna Instr. Conf. 2007

LOW MASS PROTOTYPE FOR CHLOE(FRASCATI):

G. Bencivenni et al, Vienna Instr. Conf. 2007

CYLINDRICAL GEM DETECTORS

SLIDE 41BONUS

3200 PIXELS READOUT

H. Fenker, IEEE Nucl. Sci. Symp (Puerto Rico, 2005)

EVENT DISPLAY:

RADIAL GEM TPC FOR BoNuS (JLAB)

SLIDE 42

EDRIFT ~ 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 GEMCenter 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 43

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:

HEXABOARDHEXABOARD PAD READOUT

SLIDE 44PHENIX UPGRADE - HADRON BLIND DETECTOR

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 COUNTERCsI-COATED GEM DETECTORCF4 RADIATOR

HADRON BLIND

SLIDE 45

electronshadrons

PULSE HEIGHT:

C. Woody et al., 2006 IEEE NSS/MIC ProceedingsZ. Fraenkel et al, NIMA 546(2005) 466

HADRON BLIND

ELECTRON-HADRON DISCRIMINATION:

PHENIX HADRON BLIND DETECTOR

SLIDE 46

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 14 mm

600 m

14 mm 14 mm

VERY GOOD 2-TRACK RESOLUTION

SLIDE 47

R. Bellazzini et al, Nucl. Instr. and Methods A435(2004)477

15x15 mm2 ACTIVE, ~ 100 kPIXELS (470 PIXELS/mm2)

POLARIMETERDEDICATED CMOS PIXEL READOUT CIRCUIT

SLIDE 48

MEASURE THE AVERAGE POLARIZATION OF SOFT X-RAYS

POLARIMETER

R.Bellazzini et al, Nucl. Instr. Methods A572(2007)160

1

2

1 mm2

ANGULAR DISTRIBUTION FOR POLARIZED SOFT X-RAYS:

GEM POLARIMETER

SLIDE 49GEM IMAGERPHOTON IMAGER

UV FLOODLIGHT

CsI on QUARTZWINDOW

FINE PITCH GEM30 µm HOLES @ 50 µm PITCHCMOS PIXEL READOUT

4 µm rms

R. Bellazzini et al, Vienna Instr. Conf (Feb. 2007)

SLIDE 50CRIOGENIC 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

GASMPGD

LIQUID

SLIDE 51CRIOGENIC

P. K. Lightfoot, Nucl. Instr. Meth. A554(2005)266

TWO-PHASE XENON DETECTOR FOR DARK MATTER SEARCH

GAIN CHARACTERISTICSLXe (171 º K)+2% CH4

µM+GEM

µM

CsI-COATED GEM FOR PHOTONS CONVERSION

MICROMEGAS DETECTOR

L-Xe SENSITIVE VOLUME

SLIDE 52

RATE CAPABILITY: > 3 MHz mm-2 TIME RESOLUTION: 5÷10 ns FOR PARTICLES, ~ 1 ns FOR PHOTONSLOCALIZATION ACCURACY: 60 µm IN EXPERIMENTS, ~5 µm IN LABORATORYPROPORTIONAL GAIN > 105 (SINGLE PHOTOELECTRON DETECTION)RADIATION HARDNESS: > 4.1014 MIPS cm-2 (INERT WITH HV OFF) ARBITRARY SHAPES AND READOUT PATTERN (STRIPS, PADS,…) NON-PLANAR GEOMETRY LARGE AREAS AT LOW COST: ~ 2000 cm2

SUMMARY

FUTURE IMPROVEMENTS:

MAIN PERFORMANCES:

LARGER AREAS ( ~ 1 m2), 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 53THANKS