PART 2-SELECTED DETECTORS TITLE PART 2-SELECTED DETECTORS LARGE AREA DEVICES: SPARK COUNTERS PARALLEL PLATE COUNTERS RESISTIVE PLATE CHAMBERS HIGH ACCURACY TRACKERS: GAS MICROSTRIP CHAMBERS MICROPATTERN DETECTORS GAS ELECTRON MULTIPLIER

SPARK (PESTOV) COUNTERS GOOD TIME RESOLUTION ---> THN GAP GOOD EFFICIENCY---> THICK GAS LAYER DESIGNER’S GAS MIXTURE FOR WIDE SPECTRUM PHOTON ABSORPTION: THIN GAP (100 µm) AND HIGH PRESSURES (~10 bar) HIGH RESISTIVITY ELECTRODE (PESTOV GLASS, 109 Ω cm C3H6 Yu. Pestov Nucl. Instr. and Meth. 196(1982)45 HIGH-PRESSURE GAS VESSEL METAL CATHODE Yu. Pestov et al, Nucl. Instr. and Meth. A456(2000)11 SEMI-CONDUCTING GLASS ANODE H. R. Schmidt, Nucl. Phys. B (Proc. Suppl.) 78 (1999) 372 SIGNAL PICK-UP STRIPS

SPARK COUNTER PERFORMANCES PESTOV COUNTERS SPARK COUNTER PERFORMANCES 100 µm GAP 12 BAR PRESSURE EFFICIENCY TIME RESOLUTION HV (kV) E. Badura et al, Nucl. Instr. and Meth. A379(1996)468 PHYSICAL ORIGIN OF TAILS IN THE TIME RESPONSE OF SPARK COUNTERS: A. Mangiarotti and A. Gobbi, Nucl. Instr. and Meth. A482(2002)192

ALICE TIME-OF-FLIGHT PROTOTYPE PESTOV COUNTERS ALICE TIME-OF-FLIGHT PROTOTYPE SINGLE LONG COUNTER IN CYLINDRICAL VESSEL

PHOTON-MEDIATED AVALANCHE SPREAD (DE-LOCALIZATION) PESTOV COUNTERS PHOTON-MEDIATED AVALANCHE SPREAD (DE-LOCALIZATION) CHARGE SPECTRA BEFORE AND AFTER IRRADIATION: CHARGE COUNTER FORMATION: LONG-TERM EXPOSURE TO STRONG RADIATION POLYMER COATING ON ELECTRODES INCREASES THE WORK FUNCTION CAN THIS BE UNDERSTOOD AND EXPLOITED FOR OTHER DETECTORS?

RESISTIVE PLATE CHAMBERS RESISTIVE PLATE COUNTERS (RPC) R. Santonico and R. Cardarelli, Nucl. Instr. and Meth. 187(1981)377 R. Santonico and R. Cardarelli, Nucl. Instr. and Meth. A263(1988)20 READOUT STRIPS X HV INSULATOR GRAPHITE COATING HIGH RESISTIVITY ELECTRODE (BAKELITE) GAS GAP GND READOUT STRIPS Y After a discharge elctrons are deposited on anode and positive ions on cathode Surface charging of electrodes by current flow through resistive plates Initial condition after applying high voltage I. Crotty et al, Nucl. Instr. and Meth. A337(1994)370

RESISTIVE PLATE CHAMBERS RESISTIVE PLATE CHAMBERS SYSTEMS BABAR IFR (SLAC) C. Lu, RPC Workshop, Coimbra 2001

RESISTIVE PLATE CHAMBERS RPC MUON DETECTOR FOR CMS (CERN LHC): 200 400 600 800 1000 1200 100 300 500 700 Z (cm) R (cm) BARREL RPCs ~ 400 m2 FORWARD RPCs

RESISTIVE PLATE CHAMBERS TRANSITION AVALANCHE TO STREAMER NORMAL AVALANCHE 10 mV PHOTON MEDIATED BACKWARD PROPAGATION: STREAMER 80 mV 200 mV R. Cardarelli, V. Makeev, R. Santonico, Nucl. Instr. and Meth. A382(1996)470

RESISTIVE PLATE CHAMBERS RPC RATE CAPABILITY: AVALANCHE VS STREAMER OPERATION STREAMER MODE: AVALANCHE MODE: 3.5 109 Ω cm r = 3 1011 Ω cm R. Arnaldi et al, Nucl. Physics B (Suppl) 78 (1999) 84

RESISTIVE PLATE CHAMBERS RPC RATE CAPABILITY: DEPENDS ON GAIN AND ELECTRODES RESISTIVITY MATERIAL VOLUME RESISTIVITY (Ω.cm) Pestov glass 109-1010 Phenolic (Bakelite) 1010-1011 Cellulose 5.1012 Borosilicate glass 1013 Melamine 2.1013 PROPORTIONAL (AVALANCHE) OPERATION: P. Fonte, Scientifica Acta XIII N2(1997)11

RESISTIVE PLATE CHAMBERS GAP DEPENDENCE THE SEPARATION AVALANCHE-STREAMER DEPENDS ON THE GAP: 3 mm SMALL ADDITIONS OF ELECTRO-NEGATIVE GASES EXTEND THE SEPARATION: 2 mm R. Santonico, Scient. Acta XII N2(1997)1 P. Camarri et al, Nucl. Instr. and Meth. A414(1998)317

RESISTIVE PLATE CHAMBERS RPC: INDUCED CHARGE DISTRIBUTION 2 mm gap STREAMER MODE V. Barret (ALICE di-muon trigger RPC) RPC Workshop, Coimbra 2001

RESISTIVE PLATE CHAMBERS RPC: INDUCED SIGNAL CLUSTER SIZE EFFECT OF ELECTRODE SURFACE RESISTIVITY Y. Hoshi et al, RPC Workshop, Coimbra 2001 SIGNAL PROPAGATION IN RESISTIVE PLATE CHAMBERS: W. Riegler and D. Burgarth, Nucl. Instr. and Meth. A481(2002)130

RESISTIVE PLATE CHAMBERS IMPROVING THE ELECTRODE SURFACE: LINSEED OIL TREAT THREAT COATING THE BAKELITE PLATES WITH A THIN LAYER OF LINSEED OILCONSIDERABLY IMPROVES PERFORMANCES (SMOOTHING OF LOCAL DEFECTS?) R. Santonico and R. Cardarelli, Nucl. Instr. and Meth. 187(1981)377 SINGLE RATES vs HV: AVERAGE CURRENT vs HV: NON-OILED NON-OILED AFTER OIL TREATMENT AFTER OIL TREATMENT M. Abbrescia et al, Nucl. Instr. and Meth. A394(1997)13

RESISTIVE PLATE CHAMBERS BABAR RPCS: FAST EFFICIENCY DROP PROBLEM OF QUALITY CONTRON IN LINSEED OIL COATING AND POLYMERIZATION DROPLETS, STALAGMITES, PILLARS, FRAMES C. Lu, RPC Workshop, Coimbra 2001

RESISTIVE PLATE CHAMBERS OPTIMIZATION OF RPC PARAMETERS INCREASING THE GAP PROVIDES BETTER EFFICIENCY PLATEAUX (BUT WORSE TIME RESOLUTION) RPC SIMULATION STUDIES: M. Abbrescia et al, Nucl. Instr. and Meth. A409(1998)1

RESISTIVE PLATE CHAMBERS MULTIPLE GAP RPC: BETTER EFFICIENCY AND TIME RESOLUTION HV GND DOUBLE GAP FWHM=1.7 ns SINGLE GAP FWHM 2.3 ns M. Abbrescia et al, Nucl. Instr. and Meth. A431(1999)413

RESISTIVE PLATE CHAMBERS IONIZATION RESISTIVE PLATE CHAMBERS MULTI-GAP RESISTIVE PLATE CHAMBERS WIRED “OR” BETWEEN SEVERAL GAPS s ~ 68 ps P. Fonte et al, Nucl. Instr. and Meth. A449 (2000) 295

RESISTIVE PLATE CHAMBERS MULTIGAP RPC SEVERAL RESISTIVE ELECTRODE PLATES WITH NARROW GAPS ALL INTERNAL PLATES ARE FLOATING (SET AT PROPER VOLTAGE BY ELECTROSTATICS) E. Cerron Zeballos et al, Nucl. Instr. and Meth. A 374(1996)132 HV GND FLOATING A. Akindinov et al, Nucl. Instr. and Meth. A456(2000)16

RESISTIVE PLATE CHAMBERS RPCs: OPEN PROBLEMS QUALITY CONTROL (LINSEED COATING) CHANGE OF RESISTIVITY WITH TIME (WATER DRYING?) TEMPERATURE DEPENDENCE OF RESISTIVITY RADIATION DAMAGE OF BAKELITE RADIATION-INDUCED GAS POLYMERIZATION GENERAL QUESTION: HOW TO MONITOR RESISTIVITY AND PERFORMANCE CHANGES?

MICRO-STRIP GAS CHAMBER (MSGC) Drift electrode THIN ANODE AND CATHODE STRIPS ON AN INSULATING SUPPORT Anode strip 200 µm Glass support Back plane Cathode strips A. Oed Nucl. Instr. and Meth. A263 (1988) 351.

MSGC: SIGNAL FORMATION 3-D READOUT (ANODE3, CATHODES, BACKPLANE) LIGHT CONSTRUCTION:

MSGC PERFORMANCES EXCELLENT RATE CAPABILITY AND MULTI-TRACK RESOLUTION RATE CAPABILITY > 106/mm2 s SPACE ACCURACY ~ 40 µm rms 2-TRACK RESOLUTION ~ 400 µm

MSGC SYSTEMS: NEUTRON SPECTROMETER AT ILL-GRENOBLE Ring of 50 MSGCs operated in 3He-CF4 (3.1 bar-0.8 bar)

CMS MSGC TRACKER (CERN LHC) MSGC SYSTEMS CMS MSGC TRACKER (CERN LHC) BARREL ~5500 modules FORWARD ~ 5000 modules CANCELLED (IN FAVOUR OF SILICON)

MSGC: DISCHARGE PROBLEMS MSGC DISCHARGES MSGC: DISCHARGE PROBLEMS For detection of minimum ionizing tracks a gain ~ 3000 is needed In presence of heavily ionizing particles background, the discharge probability is large ON EXPOSURE TO a PARTICLES

MSGC DISCHARGE PROBLEMS: MSGC DISCHARGES MSGC DISCHARGE PROBLEMS: FULL BREAKDOWN MICRODISCHARGES

MSGC: DISCHARGE MECHANISMS MSGC DISCHARGES MSGC: DISCHARGE MECHANISMS FIELD EMISSION FROM CATHODE EDGE VERY HIGH IONIZATION RELEASE: AVALANCHE SIZE EXCEEDS RAETHER’S LIMIT Q ~ 107 CHARGE PRE-AMPLIFICATION FOR IONIZATION RELEASED IN HIGH FIELD CLOSE TO CATHODE

NEW MICRO-PATTERN DETECTORS MICRO-GAP CHAMBER MICRO-GROOVE CHAMBER R. Bellazzini et al Nucl. Instr. and Meth. A335(1993)69 R. Bellazzini et al Nucl. Instr. and Meth. A424(1999)444

NEW MICRO-PATTERN DETECTORS MICROMEGAS: COMPTEUR A TROUS (CAT) Thin-gap parallel plate chamber Y. Giomataris et al Nucl. Instr. and Meth. A376(1996)29 Single hole proportional counter F. Bartol et al, J. Phys.III France 6 (1996)337

MICRO-PATTERN PIXEL DETECTORS NEW MICROPATTERN MICRO-PATTERN PIXEL DETECTORS MICRODOT: MICRO-PIN ARRAY (MIPA): Metal electrodes on silicon S. Biagi et al Nucl. Instr. and Meth. A361(1995)72 Matrix of individual needle proportional counters P. Rehak et al, IEEE Trans. Nucl. Sci. NS-47(2000)1426 REVIEW: F. Sauli and A. Sharma: Micropattern Gaseous Detectors, Ann. Rev. Nucl. Part. Sci. 49(1999)341

DISCHARGE POINT IN MICROPATTERN DETECTORS NEW MICROPATTERN DISCHARGE POINT IN MICROPATTERN DETECTORS ALMOST THE SAME IN ALL TESTED DEVICES: LAW OF NATURE! A. Bressan et al Nucl. Instr. and Meth. A424(1999)321

GAS ELECTRON MULTIPLIER (GEM) Thin, metal-coated polymer foil with high density of holes: 100÷200 µm Typical geometry: 5 µm Cu on 50 µm Kapton 70 µm holes at 140 mm pitch F. Sauli, Nucl. Instrum. Methods A386(1997)531

GEM DETECTOR: Cartesian Small angle Pads - multiplication and readout on separate electrodes electron charge collected on strips or pads: 2-D readout fast signal (no ion tail) - global signal detected on the lower GEM electrode (trigger) Cartesian Small angle Pads A. Bressan et al, Nucl. Instr. and Meth. A425(1999)254

MULTIPLE GEM STRUCTURES Cascaded GEMs permit to attain much larger gains before discharge Double GEM Triple GEM C. Buttner et al, Nucl. Instr. and Meth. A 409(1998)79 S. Bachmann et al, Nucl. Instr. and Meth. A 443(1999)464

a: SINGLE-DOUBLE-TRIPLE GEM GAIN Multiple structures provide equal gain at lower voltage The discharge probability on exposure to a particles is strongly reduced DISCHARGE PROBABILITY WITH a: For a gain of 8000 (required for full efficiency on minimum ionizing tracks) in the TGEM the discharge probability is not measurable. S. Bachmann et al, Nucl. Instr. and Meth. A479 (2002) 294

FAST ELECTRON SIGNAL (NO ION TAIL) GEM FAST ELECTRON SIGNAL (NO ION TAIL) The total length of the detected signal corresponds to the electron drift time in the induction gap: Full Width 20 ns (for 2 mm gap) Induced charge profile on strips FWHM 600 µm Good multi-track resolution

COMPASS TRIPLE GEM CHAMBERS Active Area 30.7 x 30.7 cm2 2-Dimensional Read-out with 2 x 768 Strips @ 400 µm pitch 12+1 sectors GEM foils (to reduce discharge energy) Central Beam Killer 5 cm Ø (remotely controlled) Total Thickness: 15 mm Low mass honeycomb support plates B. Ketzer et al, IEEE Trans. Nucl. Sci. NS-48(2001)1065 C. Altumbas et al, Nucl. Instrum. Methods A490(2002)177

400 µm 80 µm 350 µm 400 µm 2-DIMENSIONAL READOUT STRIPS GEM 2-DIMENSIONAL READOUT STRIPS Two orthogonal sets of parallel strips at 400 µm pitch engraved on 50 µm Kapton 80 µm wide on upper side, 350 µm wide on lower side (for equal charge sharing) 400 µm 80 µm 350 µm 400 µm

20 TRIPLE GEM DETECTORS BUILT FOR COMPASS AT CERN (2001-2002) BEAM: 107 Particles/second ~ 10 Tracks/event 50 µm accuracy 10 ns Time resolution

DETECTED CHARGE FOR MINIMUM IONIZING TRACKS GEM DETECTED CHARGE FOR MINIMUM IONIZING TRACKS Gain ~ 8000 Y-coordinate X-coordinate

s ~ 10% CLUSTER CHARGE CORRELATION GEM CLUSTER CHARGE CORRELATION Very good correlation, used for multi-track ambiguity resolution s ~ 10% X-Y Cluster charge correlation:

s = 12.4 ns s = 57 µm SPACE AND TIME RESOLUTION Time resolution: GEM SPACE AND TIME RESOLUTION Time resolution: Space resolution: s = 12.4 ns s = 57 µm Time resolution: computed from charge signals in three consecutive samples (at 25 ns intervals) s = 12.4 ns Traks fit with two TGEM and one silicon micro-strip After deconvolution s = 46±3 µm

GEM TIME RESOLUTION Triple GEM with pad readout for LHCb muon detector G. Bencivenni et al, Nucl. Instr. and Meth. A478(2002)245

GEM APPLICATIONS FAST X-RAY IMAGING Using the lower GEM signal, the readout can be self-triggered with energy discrimination: A. Bressan et al, Nucl. Instr. and Meth. A 425(1999)254 F. Sauli, Nucl. Instr. and Meth.A 461(2001)47 9 keV absorption radiography of a small mammal (image size ~ 60 x 30 mm2)

GEM: HIGH PRESSURE OPERATION GEM APPLICATIONS GEM: HIGH PRESSURE OPERATION Neutron detection in He3? A. Bondar, A. Buzulutskov, L. Shekhtman, V. Snopkov and A. Vasiljev, Subm. Nucl. Instr. and Meth. (2002)

GEM APPLICATIONS GEM chamber with pad readout to detect the direction of the photoelectron produced by X-rays X-RAY POLARIMETER Charge asymmetry: 5.9 KeV unpolarized source 5.4 KeV polarized source E. Costa et al, Nature 411(2001)662 R. Bellazzini et al Nucl. Instr. and Meth. A478(2002)13

PHOTON DETECTION WITH MULTI-GEM GEM APPLICATIONS PHOTON DETECTION WITH MULTI-GEM Multiple GEM detectors permit to achieve very large gains (106) in photocathode-friendly pure noble gases or poorly quenched mixtures. Reduced transparency strongly suppresses photon and ion feedback A. Buzulutskov et al, Nucl. Instrum. Methods A443(2000)164 Large area position-sensitive photomultipliers R. Chechik et al, Nucl. Instr. and Meth. A 419(1998)423

GEM OPERATION IN CF4 Photoelectron extraction from CsI: GEM APPLICATIONS GEM OPERATION IN CF4 Photoelectron extraction from CsI: A. Breskin, A. Buzulutskov, R. Chechik Nucl. Instr. and Meth. A 483(2002)658

SEALED GEM PHOTOMULTIPLIER GEM APPLICATIONS SEALED GEM PHOTOMULTIPLIER Semi-transparent CsI photocathode Single photo-electron signals: A. Breskin et al, Nucl. Instr. and Meth. A478(2002)225

Proton and Triton tracks by neutrons in 3He GEM APPLICATIONS GEM OPTICAL IMAGER Scintillation light in a multiple GEM detector recorded by a CCD camera - particle tracks Proton and Triton tracks by neutrons in 3He F.A.F. Fraga et al, Nucl. Instr. and Meth. A478 (2002) 357

TIME-RESOLVED PLASMA DIAGNOSTIC GEM APPLICATIONS TIME-RESOLVED PLASMA DIAGNOSTIC PINHOLE GEM CAMERA WITH PIXEL READOUT: Plasma emission (~ 1.5 keV) sampled at 10 kHz FIRST OBSERVATION OF PLASMA ROTATION BEFORE DUMP! Courtesy D. Pacella, Princeton Plasma Physics Laboratory D. Pacella et al, Rev. Scient. Instrum. 72 (2001) 1372 R. Bellazzini et al, Nucl. Instr. and Meth. A478(2002)13

GAS DETECTORS DEVELOPMENT WEB PAGES: BIBLIOGRAPHY BASIC BIBLIOGRAPHY IONIZATION CHAMBERS AND COUNTERS, D.H. Wilkinson (Cambridge Univ, Press, 1950) ELECTRON AND NUCLEAR COUNTERS, S.A. Korff (Van Nostrand, New York 1955) BASIC DATA ON PLASMA PHYSICS, S.C. Brown (Wiley, New York 1959) ELECTRON AVALANCHES AND BREAKDOWN IN GASES, H. Raether (Butterworth, London 1964) COLLISION PHENOMENA IN IONIZED GASES, E.W. McDaniel (Wiley, New York 1964) ATOMIC AND MOLECULAR RADIATION PHYSICS, L.G. Christophorou (Wiley, New York 1971) SPARK, STREAMER, PROPORTIONAL AND DRIFT CHAMBERS, P. Rice-Evans (Richelieu, London 1974) PRINCIPLES OF OPERATION OF MULTIWIRE PROPORTIONAL AND DRIFT CHAMBERS, F. Sauli (CERN 77-09, 1977) TECHNIQUES AND CONCEPTS OF HIGH-ENERGY PHYSICS, ed. by Th. Ferbel (Plenum, New York 1983) TECHNIQUES FOR NUCLEAR AND PARTICLE PHYSICS EXPERIMENTS, W.R. Leo (Springer-Verlag, Berlin 1987) RADIATION DETECTION AND MEASUREMENTS, G.F. Knoll (Wiley, New York 1999) RADIATION DETECTORS, C.F.G. Delaney and E.C. Finch (Clarendon Press, Oxford 1992) SINGLE PARTICLE DETECTION AND MEASUREMENT, R. Gilmore (Taylor and Francis, London 1992) INSTRUMENTATION IN HIGH ENERGY PHYSICS, ed. by F. Sauli (World Scientific, Singapore 1992) PARTICLE DETECTION WITH DRIFT CHAMBERS, W. Blum and l. Rolandi (Springer-Verlag, Berlin 1993) PARTICLE DETECTORS, K. Grupen (Cambridge Monographs on Part. Phys. 1996) REVIEW ARTICLES G. Charpak and F. Sauli: High-resolution electronic particle detectors, Ann. Rev. Nucl. Part. Sci. 34(1984)28 J. Va’vra: Wire chambers aging, Nucl. Instr. and Meth. A323(1992)34 F. Sauli and A. Sharma: Micropattern Gaseous Detectors, Ann. Rev. Nucl. Part. Sci. 49(1999)341 GAS DETECTORS DEVELOPMENT WEB PAGES: http://www.cern.ch/GDD MSGC, GEM Bibliography Papers