1. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa1 Progress in Micro Pattern Gas Detectors R. Bellazzini INFN - sez. Pisa Vienna Conference on Instrumentation 2001

2. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa2 Outline Why are we interested in Micro Pattern Gas Detector? Performances and limitations Solutions with Single-stage Devices Solutions with Multi-stage Devices Some ‘exotic’ applications Conclusions Two recent, excellent reviews: F.Sauli, 8th Pisa Meeting on Advanced Detectors, Elba 2000 A. Sharma, IEEE NSS and Medical Imaging Conference, Lyon 2000

3. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa3 Electric field Signals

4. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa4  Spatial resolution = 30.5 ± 0.4  m Overall spatial resolution Ne(25)-DME(75) Vcath= -530 V Vdrift= -3000 V MSGC Residuals distribution

5. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa5 Global Occupancy at different S/N (ORCA2 sim.) 48 minimum bias events in 3 bunch crossings MSGC

6. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa6 Rate capability > 1 MHz/mm 2 MSGC

7. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa7 E field on insulating substrate E field on thin conducting layer (coating) over insulating substrate Uncoated MSGC Coated MSGC MSGC

8. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa8 At high gain on exposure to heavily ionizing particles possible discharges MSGC Advanced passivation Standard passivation A. Bressan et al., Nucl. Instr. Meth. A424 (1998) 321 Solution! Cathode edge passivation

9. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa9 Telescope of 32 MSGCs tested at PSI in Nov99 (Milestone) MSGC

10. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa10 MSGC 350-400 MeV/c  + /p beam. MIP spectrum with non-negligible HIP rate. 4 channels (out of 16000) lost in ~400 hrs run 32 days exposure @LHC rate! (Max rate ~6 KHz/mm 2 ) R. Bellazzini et al., Nucl. Instr. Meth. A457 (2001) 22 Spark rate 1/day/detector in the whole telescope

11. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa11 Measured spark probability  4 10 -13 MSGC

12. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa12 MSGC Strip loss history during the whole PSI Test Beam period (5 weeks H.I.)

13. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa13 MSGC Detection efficiency vs S/N ~ 98% at S/N = 13

14. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa14 MSGC Example of gain stability at low and high intensity 3 weeks run

15. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa15 Exploited 2D-Reconstruction capability with Pion beam MSGC

16. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa16 Summary of PSI-Milestone for CMS Barrel MSGCs 32 barrel modules exposed for 5 weeks of HI at PSI; no single access, no single short, no cathode trips; lost 40% of 1 strip and 2 electronic channels (3 including margin phase); margins explored up to a factor 2.4 without any significant increase of spark rate and strip loss; lifetime = 20 times the expected one; system brought back in perfect integrity ( < 1.4 % dead channels) measured discharge probability = 4 10 -13 MSGC From the Addendum to the CMS tracker TDR by the CMS collaboration: “ In the fall of 1999, the large scale PSI Milestone (~40 k strips exposed for 5 weeks) resulted in an unambiguous demonstration of the viability of the CMS MSGC’s for tracking at the LHC.”

17. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa17 GEM F. Sauli, Nucl. Instr. Meth. A386 (1997) 531 70  m 140  m Transfer Multiplication Conversion and drift

18. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa18 GEM + MSGC Applications: HERA-B, CMS Forward Tracker

19. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa19 GEM + MSGC HERA-B Detector

20. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa20 GEM + MSGC M. Holhmann, 8th Pisa Meeting on Advanced Detectors, Elba 2000 HERA-B: High rate experiment

21. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa21 GEM + MSGC HERA-B Inner Tracker: the world’s largest Micro Pattern Detector MSGC-GEM detectors R min ~ 6 cm  10 6 particles/cm 2 sec 300  m pitch 184 chambers: max 25x25 cm 2 ~ 10 m 2 140.000 channels M. Holhmann, 8th Pisa Meeting on Advanced Detectors, Elba 2000

22. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa22 GEM + MSGC HERA-B : Spark rate and exposure time Gem+MSGC appear to be adequate solution even if they need long and careful HV training in the beam

23. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa23 GEM + MSGC Courtesy F. Eisele (Desy) HERA-B GEM+MSGC Hit efficiency ~ 90÷96 % (after individual V GEM adjustment)

24. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa24 GEM + MSGC HERA-B : tracks in the Inner Tracker Courtesy F. Eisele (Desy)

25. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa25 CMS Forward Tracker PSI Test Beam Set-up 18 MSGC+GEM modules GEM + MSGC

26. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa26 GEM + MSGC High intensity event reconstruction CMS Forward MSGC+GEM modules M. Ageron et al., Preprint sub. Nucl. Instr. Meth., 21 June 2000

27. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa27 Detection efficiency vs S/N M. Ageron et al., Preprint sub. Nucl. Instr. Meth., 21 June 2000 PSI low intensity run GEM + MSGC ~ 98% at S/N = 17

28. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa28 M. Ageron et al., Preprint sub. Nucl. Instr. Meth., 21 June 2000 GEM + MSGC (HI runs @ S/N premux ~ 37) Milestone ceiling Strip loss history during the 3 weeks of PSI-Milestone Test Beam

29. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa29 GEM + MGD PSI99  M1 TB - Low Intensity S/N Two-stages Micro Pattern detector: GEM + MicroGroove Detector

30. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa30 GEM + MGD 1 week high intensity run: NO sparks, NO loss of strips or electronic channels at low transfer field (4 kV/cm) PSI99-  M1 Test beam

31. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa31 Double - Triple GEM S. Bachmann, CERN-EP/2001-151 Double-GEM detector Discharge probability vs gain for  -particles Fast read-out (electrons) 2D capability Single GEM (uniform field) more prone to sparking than MSGC (sharp field)

32. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa32 Double - Triple GEM The PSI  M1 beam @ 300 MeV/c reproduces very well LHC spectra  -beam  -particles

33. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa33 Double - Triple GEM PSI installation: large area (31 x 31 cm 2 ) segmented GEMs COMPASS Double GEM

34. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa34... even though the detectors experienced several thousands of discharges in the course of the discussed test beam experiments, damages were not observed neither to the GEM foils nor to the readout electronics. (S. Bachmann et al., CERN-EP/2000-116) Double - Triple GEM COMPASS Double GEM prototype

35. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa35 Double - Triple GEM COMPASS B. Ketzer IEEE NSS and MI Conference 19 October 2000

36. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa36 Double - Triple GEM Triple GEM detector for LHCb inner tracker Detection efficiency vs GEM Voltage M. Ziegler et al., hep-ex/0007007, 6 July 2000 375V

37. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa37 Double - Triple GEM @ 375V (beginning of plateau) Discharge probability ≈ 8.3x10 -12 (45 sparks in 2 det. in 12.5 hrs) M. Ziegler et al., hep-ex/0007007, 6 July 2000 Gain and Discharge probability vs GEM Voltage

38. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa38 Applications: MSGC The JEM-X Project on INTEGRAL ( a  -ray observatory satellite) Danish Space Research Institute To be launched this year by ESA

39. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa39 The JEM-X Detector consists of 2 identical, high pressure, 2D-MSGCs. The gas filling is a mixture Xenon-Methane (Gain ~ 1500). The diameter is 250 mm, corresponding to a collecting area of 500cm 2 Applications: MSGC Qualification model2D-MSGC plate

40. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa40 Applications: MSGC Spectral sensitivity of the JEM-X qualification model Courtesy C. Budtz-Jorgensen (DSRI)

41. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa41 Applications: MSGC Response of JEM-X to a full area illumination Courtesy C. Budtz-Jorgensen (DSRI)

42. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa42 GEM + Pixel Read-Out The complete separation between the amplification structure and the pick-up electrodes allows full flexibility on the choice of read-out pattern  GEM+Micro Pixel electrode Recent applications: X-ray Polarimeter Time resolved plasma diagnostic

43. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa43 GEM + Micro Pixel Read-Out Heitler W.,The Quantum Theory of Radiation 8-layer read-out board Pixel size 0.2 mm Area 2.4 x 2.4 mm 2 (128 pixels) X-ray Polarimeter

44. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa44 GEM + Micro Pixel Read-Out Reconstructed emission angles of the photoelectron Photoelectron tracks reconstruction (larger boxes == larger energy losses) Unpolarized photons E. Costa et al. Polarized photons Interaction point and Auger e -

45. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa45 GEM + Micro Pixel Read-Out Observing time to measure at 99% confidence level the degree of polarization of galactic and extra-galactic sources with traditional and MP polarimeters Degree of polarization Extra-galactic sources

46. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa46 New implementation: 512 independent chans out of 30 mm 2 area GEM + Micro Pixel Read-Out

47. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa47 GEM + Macro Pixel Read-Out Ultra-fast system for X ray imaging based on GEM New diagnostic device in soft X range (3  15 KeV) for magnetic fusion plasmas Printed circuit board 128 pixels (2.5 x 2.5 cm 2 ) Parallel read-out

48. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa48 GEM + Macro Pixel Read-Out The inner toroid The Frascati TOKAMAK (FTU) Bt = 8 T, Ip = 1.6 MA R = 0.93 m a = 0.3 m

49. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa49 GEM + Macro Pixel Read-Out Linearity of GEM current at very high counting rates. Counting rate linear up to 2 MHz/pixel (limited by electronics dead-time) D. Pacella et al., Review of Scientific Instrument, Vol.72 No.2 (2001)

50. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa50 GEM + Macro Pixel Read-Out 1 KHz sampling - 3 MHz/pixel counting rate  Multiple injections of D2 pellets Time (ms) Time response from 4 pixels for ohmic plasma Counts / ms

51. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa51 GEM + Macro Pixel Read-Out X-ray time response for two different injection runs 20 KHz sampling, 3 MHz/pixel counting rate Normal Aborted

52. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa52 GEM + Macro Pixel Read-Out Imaging capabilities at high rates (2MHz/pixel) Image of a wrench placed close to the detector Exposure time = 50 ms

53. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa53 Double GEM + Macro Pixel Read-Out Spectra of B (183 eV) and O (523 eV) in vacuum Double GEM Gain = 20000 C. Buttner et al., Nucl. Instr. Meth., A409 (1998) 79 D. Pacella et al.

54. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa54 GEM + Macro Pixel Read-Out Thresh.> 0.1 KeV Thresh.> 0.6 KeV Spectral map and composition of fusion plasma Courtesy of D. Stutman, Johns Hopkins University

55. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa55 New Micro-Pattern Structures F. Bartol et al., J. Phys III France 6 (1996) 337 MICROCAT A. Sarvestani et al., Nucl. Instr. And Meth. A410 (1998) 238 Compteur a Trou (CAT)

56. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa56 MICROMEGAS Y. Giomataris et al., Nucl. Instr. And Meth. A376 (1996) 29 New Micro-Pattern Structures Large MICROMEGAS (40x40cm 2 ) for COMPASS Y. Giomataris, F.Kunne, F. Jeanneau, P. mangeot Low field: conversion and drift Very high field: multiplication

57. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa57 New Micro-Pattern Structures MICRO-WIRE chamberMICRO-PIN ARRAY Detector (MIPA) B. Adeva et al., Nucl. Instr. And Meth. A435 (1999) 402 P. Rehak et al., IEEE Nucl. Sci. Symposium seattle 1999

58. Micro Pattern Gas Detectors VCI- Vienna Conference on Instrumentation 2001 R.Bellazzini - INFN Pisa58 Conclusions The field of Micro Pattern Gas Detector is STILL showing great vitality and propulsion. Single stage and Multistage Devices showed suitable for tracking at high luminosity. Competition of solid state devices is becoming HARD, especially at hadron machines. Great potential as X-ray detectors. Coupling of distributed amplification structures (GEM,…) to separate, pixel read-out structures seems the most exciting perspective.