GEM , Resistive M-Bulk - PowerPoint Presentation

1. GEM , Resistive M-Bulk , ThGEM detector production.Rui De Oliveira, Cosimo Cantini, Antonio Teixeira, Olivier Pizzirusso, Julien BurnensAnnecy 26/04/201226/04/121Rui De Oliveira

2. CERN PCB Workshop26/04/12Rui De Oliveira218 persons Building :1000 sqr metersMaking PCBs since 1960-PCB -Rigid -Flex -Flex-rigid -Micovias -fine line (15um) -large size (up to 2m) -Thick film Hybrids -Thin film Hybrids-Chemical milling -Cu, Fe, Al, Au, Ag, W, Mb, Ti, Cr, Ni-MPGD -GEM/thinGEM/THGEM/RETHGEM -MSHP/Cobra -MICROMEGA/ Bulk/ Micro-BULK -RES BULK -Resistive MSGC -Low mass circuits -Multilayer flexes with aluminum strips -embedded heat sinks (carbon, graphite, metals, diamon)-Embedded components -passive -Active

3. GEM Large size situationDetector without spacersMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/123Rui De OliveiraOUTLINE

4. 26/04/12Rui De Oliveira4 GEM FoilPresent size 1.2m x 0.6m Future max size 2m x 0.6m Std pattern 140um pitch/70um holes

5. 26/04/12Rui De Oliveira5Base material : Polyimide 50um + 5um on both sidesPolyimide : Apical NP from company Kaneka (Japan)Supplier of the copper clad material : Nippon Mining (Japan)GEM double mask Vs GEM single MaskSame base material Hole patterning in Cu Polyimide etch Bottom electro etch Second Polyimide Etch Limited to 40cm x 40cm due toMask precision and alignmentLimited to 2m x 60cm due toBase material EquipmentDouble mask Single mask

6. 26/04/12Rui De Oliveira6GEM Double mask Vs GEM single MaskSimilar patterns , similar behavior, same material.Angles can be adjusted in both structure (Typ value : 70um copper hole , 50um polyimide hole) Steeper angles gives lower gain but also lower charging up

7. COMPASS (CERN)7GEM double mask examplesLHCb-Muon trigger (CERN)TOTEM (CERN)WindowDrift electrodeGEM stackPad Plane Support & Media-DistributionCooling Support & LV- DistributionFront-End ElectronicShielding Cover & Read-out PlaneSTAR experiment (US)26/04/12Rui De OliveiraPresent double mask production quantities : around 500 GEMs/ year in averageMax size: 40cm x 40cm

8. 8GEM Single mask examplesKLOE – Cylindrical 3 GEM DetectorGEM 800mm x 500mmRead-out 2D : 800mmx 500mmCMS RPC possible upgrade GEM 1.1m x 500mm Present production rate : 100 Gem /year (1.2mx0.6m)Expected rate for 2012 : 250 GEM/Year/technician26/04/12Rui De Oliveira

9. GEM Large size situationDetector without spacersMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/129Rui De Oliveira

10. No spacer No stretching structure: NS2 26/04/12Rui De Oliveira1010 to 15mmReadout connectorO-ring GEM attaching structure(4 pieces defining gaps)Drift electrodeFree to slide External screws to adjuststretching GNDGNDgluing

11. 26/04/12Rui De Oliveira11FRAMEGEMHV DIVIDERDRIFT BOARDCLOSEDDETECTOR30 x 30 cmScrewsO-ringHV BNC ConnectorGas connectorsRead-out connectors1m x 0.5m under production

12. No spacers in active areaAssembly time ½ hour for 10cm x 10cm detector (1 technician)2 hours for 1m x 0.6m detector (1 technician)No gluing , no solderingRe opening possibleGEM exchange possibleFull detector Re-cleaning possible No intermediate testNew GEM stretching method (NS2) advantages:26/04/1212Rui De Oliveira

13. GEM Large size situationDetector without spacersMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/1213Rui De Oliveira

14. 26/04/1214PCBlaminationMesh depositlaminationdevelopmentRui De OliveiraLarge MicromegasLargest size produced:1.5m x 0.6mLimited by equipment BULK TechnologyDUPONT PC 1025 coverlayBOPP MeshesSERITEC stretching

15. 15Fine segmentation 1cm², thickness 8mm for ILC Hadronic calorimetryTested in the RD51 1 kHz beamBulk Micromegas ILC DHCAL first m2LAPP Annecy26/04/1215Rui De OliveiraPad read-out large TPCNeutrino detector10 sqr meter in serviceT2K experimentJapan

16. Atlas CSC replacement project 26/04/12Rui De Oliveira16MPGD Vs Wire chambers-Faster-no need for fancy gases-lower cost-robust1.2m x 0.6m

17. Resistive Bulk MicroMegas structure 26/04/12Rui De Oliveira17

18. 26/04/12Rui De Oliveira18Resistive strip processPCBPCBPCBPCBPCB-Good resistor uniformity-Easy to clean-Thermally robustRead-out strips or padsCopper lamination layerResistive inverse patterningResistive layer depositionCopper stripping

19. 26/04/12Rui De Oliveira19Atlas CSC replacement project Double sided BoardResistive strip depositBulkingTest before closingClosing

20. 26/04/12Rui De Oliveira20Situation and on going productions Situation on large STD BULKUp to 5 detectors (1.5m x 0.6m max) produced all goodSituation on large resistive detector production4 CSC type (1.2m x 0.6m) 1D produced 1 goodPhysical parameters OK , leakage current out of tolerance4 MSW type (1.2m x 0.6m) 2D produced 1 goodPhysical parameters OK , leakage current out of toleranceYield 25% due to dust contamination (solution found recently)Ionic contamination and pillar shape are not the cause of leakage currentsNext production with corrections1 detector 1 m x 1m end of June

21. GEM Large size situationDetector without spacersCompact HV dividerMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/1221Rui De Oliveira

22. Resistive stripsBulk MicroMegas resistive anode and 2D readout26/04/12Rui De OliveiraWe have produced : X/Y read-out U/V/W read-out Grounded mesh detectors22

23. 26/04/12Rui De Oliveira23X/Y read-outU/V/W read-out

24. GEM Large size situationDetector without spacersCompact HV dividerMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/1224Rui De Oliveira

25. 26/04/12Rui De Oliveira25THGEM description: -800mm x 400mm Halogen Free -1mm & 2mm thick -RIM 40um (differential etching) -0.8mm pitch -0.5mm hole diameter@ ELTOS:-Drilling-Photolithography-Differential etching@ CERN: -Thermal treatment -Passivation -Cleaning -Electrical TestTHGEM and read-out for Double phase pure argon LEM-TPC with 2D anode

26. GEM Large size situationDetector without spacersCompact HV dividerMicromegasLarge size situationX/Y and U/V/W readoutThick GEMLarge size situationProtection 26/04/1226Rui De Oliveira

27. THGEM: limitations Strong ionizing particles produce sparks. Sparks damage the electrodes and are responsible of a low degradation of the gain.The active element then drains steadily a DC current from the power supply.27 Ideas to cancel the phenomenum :-increase the number of TH GEM (we want to avoid)- Reduce the capacity by segmenting the THGEM - Decouple sectors with resistors- Resistive electrodes- Change metal- Rim , no rimChange dielectricsAfter long sparking period they all failed but some structures are 1000 time better than othersWe went back to theory to understand the problem26/04/12Rui De Oliveira

28. Voltage-Current Characteristic of the DC Electrical Discharges- Gas Discharge Physics, Yuri P. Raizer- DC pulse-powered micro-discharges on planar electrodes, Yogesh B. GianchandaniBreakdowntriggeredSelf maintained28C :negligibleavalancheCoronaGlow dischargeSpark26/04/12Rui De Oliveira

29. 29V: supply voltage (2KV)R: limiting resistor (1Mohms)C: THGEM capacity (1nF)R’: spark local surface resistor (10 Ohms) : sparkI : charge currentI’: discharge current inside capacitorCharge  T = RC (1us)I max =V/R= 2mA (limited to 10uA)Spark discharge T = R’C (10ns) I’ max = (200 A)That’s consistent with measurementsCVcVII’26/04/12Rui De Oliveira

30. 30Initial Working pointR’ low valueRepetitive sparksEnd working pointR’ value > RDC currentR’ increaseDue to spark damage ex:1 MOhmsR’ is low Clean metal ex: 10 Ohms26/04/12Rui De Oliveira

31. ?26/04/12Rui De Oliveira31High energy Sparks Glow dischargePerfect Hole ?Low energy sparks?

32. Thank youQuestions?26/04/12Rui De Oliveira32