1. 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

2. 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

3. 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

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

5. 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?

6. 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

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

8. 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

9. 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

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

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

12. 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

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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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?

22. 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.

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

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

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

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

27. 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

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

29. 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. 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

38. 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

39. COMPASS TRIPLE GEM CHAMBERS
Active Area 30.7 x 30.7 cm2
2-Dimensional Read-out with
2 x 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

40. 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

41. 20 TRIPLE GEM DETECTORS BUILT FOR COMPASS AT CERN (2001-2002)
BEAM: 107 Particles/second ~ 10 Tracks/event
50 µm accuracy ns Time resolution

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

43. 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:

44. 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

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

46. 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)

47. 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)

48. 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

49. 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

50. 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

51. 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

52. 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

53. 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

54. 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:
MSGC, GEM
Bibliography
Papers