1. NoV. 11, 2009 WP meeting 94 1 D. Attié, P. Colas, E. Ferrer-Ribas, A. Giganon, I. Giomataris, F. Jeanneau, P. Shune, M. Titov, W. Wang, S. Wu RD51 Collaboration Meeting - Bari October 8 th, 2010 Characterization of Micromegas resistive detectors for the MAMMA project Within the MAMMA collaboration Arizona, Athens(U, NTU, Demokritos), BrookhaVen, CERN, Harvard, Istanbul, Naples, CEA Saclay, Seattle, USTC Hefei, South Carolina, St. Petersburg, Shandong, Stony Brook, Thessaloniki

2. The MAMMA project: Muon Atlas MicroMegas ActiVity (J. Wotschack) The Saclay beam test in 2009 at Cern: –Resistive detector efficiency in high intensity beam –Preliminary results Next beam test preparation and resistive bulk characterization –Gain measurement –Stability in time –Spark topology of the resistive detectors Conclusion DaVid.Attie@cea.fr2 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Overview

3. Increase of the neutron, photon and hadron background Replacement or upgrade of the muon forward chambers Requirements: –High rate capability (≤ 10 kHz.cm-2) –Spatial resolution ~100 µm ( θ ≤ 45 °) –Radiation hardness and good ageing properties –Time resolution ~few ns –Level1 triggering capability –Large surface MPGD: Bulk Micromegas –Fast and efficient ion collection –TPC mode possible: sensitivity to incidence angle. –« bulk » production process suitable for large surfaces DaVid.Attie@cea.fr3 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 The MAMMA Project L sLHC = 10 × L LHC = 10 35 cm 2.s -1   Resistive coating may solve the sparking issue

4. DaVid.Attie@cea.fr4 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 The Saclay beam test setup at CERN (2009) Aim : test different resistive film detectors and compare behaviour to non-resistive detectors in order to operate in high rate Telescope : 3 X-Y detectors (10  10 cm 2 ) Electronics : GASSIPLEX DA Q: realised by Demokritos Gas : 95%Ar + 3% CF 4 + 2% isobutane Tested detectors : - Standard bulk detectors - Resistive coating detectors - Segmented mesh detector 120 GeV π + Y Resistive Non-Resistive XYX X Beam 1 mm0.25 mm1 mm Detectors in test Y SPS-H6

5. DaVid.Attie@cea.fr5 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Current and voltage behaviour at 10 KHz/cm² Standard bulk (SLHC2: 2mm) Resistive strip bulk (R6: 1mm, 400kΩ/ □ ) SLHC2 : HV=400V (Gain ~3000): - current when sparking < 0.4 mA -voltage drop< 5% R6 : HV=390V (Gain ~3000): - current when sparking < 0.08 mA -voltage drop<0.5% Ar /CF 4 /Iso (95/3/2)

6. DaVid.Attie@cea.fr6 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Summary of the 2009 beam test (Gain~3000) TypeNamePitchProperties Spark rate (s -1 ∙cm -2 ) Spark current (mA) Voltage drop Standard bulkSLHC22 mmNon resistive0.45% Resistive coating R32 mm 2 MΩ/ □, kapton+insulator 0.22% R52 mm 250 MΩ/ □, resistive paste 0.11.5% R61 mm 400 KΩ/ □, resistive strip 0.080.5% R70.5 mm tens of KΩ/ □, resistive pad 0.354.5% Segmented mesh S11 mm8 segmentations--- R3 R6R5S1

7. DaVid.Attie@cea.fr7 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Spatial resolution R6(1mm pitch, 400k Ω / □ )R3(2mm pitch, 2M Ω / □ ) δ =105µm δ MM = 80µm δ =241µm δ MM = 231µm δ : define by residuals of the cluster position and extrapolated track from telescope: δ MM : convolution of: - the intrinsic Micromegas resolution - the track resolution (extrapolated) ~68µm

8. DaVid.Attie@cea.fr8 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Cluster size Resistive detectors: Standard detector: Ar /CF 4 /Iso (95/3/2)

9. DaVid.Attie@cea.fr9 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Track position With hit in the tested detectorWithout hit in the tested detector Inefficiency due to pillars and misalignment

10. DaVid.Attie@cea.fr10 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Set-up for the next test beam at Cern Y Resistive XYX X 0.5 mm0.25 mm0.5 mm Detectors to be tested Y Resistive YXYX New telescope : 3 X-Y detectors(10 x 10 cm 2 ) smaller pitch built in Saclay bulk workshop Electronics : GASSIPLEX (96 channels per detector) DA Q: more recent computer recording the spark counting and beam trigger Gas : 98%Ar + 2% isobutane Trigger improvement : PMs as close as possible to the telescope New detectors to be tested : (built at Cern by Rui) TypeNamePitchProperties Resistive coating R80,5 mm 2 MΩ/ □, kapton+insulator R9-R112mm R12, R130.5mm 300 KΩ/ □, resistive strip R14, R151mm R16, R171mmJoerg-like

11. DaVid.Attie@cea.fr11 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Gain cures in Ar/Isobutane 2% Ar/Iso (98/2)

12. DaVid.Attie@cea.fr12 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Signal evolution in time for resistive detectors Ar/Iso (98/2)

13. DaVid.Attie@cea.fr13 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Normalized signal evolution of the resistive detectors Ar/Iso (98/2)

14. DaVid.Attie@cea.fr14 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Detector characteristics summary in Ar/C 4 H 10 (97:2) Resistive Bulk detector Strip pitch Resistive coating type Detector capacitance Energy Resolution 55 Fe (FWHM) Max. gain R80,5 mm C-loaded Kapton 2 M Ω / □ 633 pF23,1% (310V)25100 (365V) R9 2 mm 1,45 nF23,2% (320V)12850 (360V) R101,67 nF22,1% (310V)23250 ( 360V) R111,72 nF21,4% (310V)24100 (360V) R12 0,5 mm Resistive strips 300 k Ω / □ 637 pF24,4% (320V)25700 (360V) R13643 pF29,3% (300V)35500 ( 360V) R14 1 mm 943 pF26,7% (320V)34300 ( 360V) R15941 pF28,9% (310V)33000 (360V) R16 Resistive Joerg -Type 941 pF34,3% (320V)33000 ( 365V) R17943 pF29,8% (310V)33650 (365 V) Standard Bulk detector Strip pitch Detector capacitance Energy resolution 55Fe (FWHM) Maximum gain Proto11 0,5 mm 613 pF18.2% (320V)26300 (360V) Proto12608 pF22.2% (310V)23250 (360V) Proto13604 pF18% (300V) 25700 (360V)

15. DaVid.Attie@cea.fr15 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Simple model

16. Measurement through a 1 M Ω resistor Detector divide in four parts Sparks triggered by  source ( 241 Am) HV drift = -450V (5 mm gap) HV mesh up to sparks arising Threshold = 1V DaVid.Attie@cea.fr16 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Spark study 1M Ω Oscilloscope Channel 1 Channel 2 Channel 3 Channel 4 23 strips 1OO mm

17. DaVid.Attie@cea.fr17 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Standard bulk V mesh = 330V Trigger on Channel 2

18. DaVid.Attie@cea.fr18 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Resistive Kapton 2 MΩ/□ Trigger on Channel 3 Connector issue on channel 4 V mesh = 380V

19. Trigger on Channel 2 V mesh = 340V DaVid.Attie@cea.fr19 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Spark behaviour in resistive detectors R14, Resistive strips 300 k Ω/ □ R17, Joerg like

20. Trigger on Channel 2 V mesh = 340V DaVid.Attie@cea.fr 20 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Charge seen by the strips R14, Resistive strips 300 k Ω/ □ R17, Joerg like G 380V ~ 2  G 360V Q 380V ~ 1.2  Q 360V & V mesh = 360V

21. DaVid.Attie@cea.fr21 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Spark topology of resistive detectors Detector typeSparking HVReleased chargeSignal duration Standard-330VFew tens nC <50  s CLK-380VFew nC 100-250  s Resistive strips-340VFew nC 50  s Joerg -like -350V< 0,2 nC 50-100  s Resistive strip detector has similar spark signal (exponential) than non-resistive detector but with an attenuation about 30 % and similar time constant (  =RC) Carbon-Loaded Kapton and Joerg -like detectors have shaping-like signals but the Joerg -like detector signal are shorter and ten times smaller Signal from CLK are seen on the adjacent pads.

22. DaVid.Attie@cea.fr22 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Conclusions It is still to soon to say that a resistive coating could solve the spark from operation. In some configuration the resistive coating is able to contain or even suppress the spark signal. We are now ready for the next beam test at Cern to determine in high rate condition operation the efficiency of the various resistive Micromegas. After the choice of a technology spark proof, other stages are to come, ageing studies, larger surface, etc…

23. DaVid.Attie@cea.fr23 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010

24. DaVid.Attie@cea.fr24 RD51 Collaboration Meeting, Bari ̶ October 8 th, 2010 Garfield simulation for Argon/Isobutane gas mixture