GridPix/Gossip for ATLAS SCT Upgrade ILC CLIC

1. GridPix/Gossip for ATLAS SCT Upgrade ILC CLIC …….insulators in strong E- fields………. …….the frustration of innovation……….. Harry van der Graaf Nikhef, Amsterdam IEEE-NSS Conference MPGD-Si Detector Workshop Dresden, Oct 18, 2008

2. Micro Strip Gas Counters: hard to operate: • discharges, ruining electrodes • ageing • ! Very strong electric field in insulator’s volume & surface !

3. GEMs: • often cascade of 3 GEMs used to limit gain per GEM to ~40 • ‘rim’ (dia hole Cu/kapton) critical • shape of hole wall critical • charge up effects

4. Overview of MPGD development in JAPAN Atsuhiko OCHI Kobe University, JAPAN 13 Oct. 2008 2nd RD51 workshop in Paris

5. x750 Recent Status of Development GEM Production RIKEN/SciEnergy GEM (thick-foil and fine-pitch) pitch 80um hole 40um thickness 100um Remove copper by wet etching 100um 80um Irradiate CO2 laser Remove remaining edge from the other side

6. Fe-55 spectrum 5.9keV Recent Status of Development Gain Curve (RIKEN GEM) • GEM test setup and parameters • Thick-foil and fine-pitch GEM • (single layer) • HV supplied through a resister chain • Ed=2.5kV/cm, Ei=4~5kV/cm, ⊿VGEM=300~600V • Gas: Ar+CO2(30%) flow • Readout by 1cm x 1cm pad • Gain measurement • Gain vs applied voltage • X-ray from Fe-55 (5.9keV) gain=3x104 To keep good spatial resolution and keep discharge point at high gain. Our GEM is most suitable for Cosmic X-ray Polarimeters.

7. Recent Status of Development Gain instability (RIKEN GEM) No increase and decrease just after HV on. 3 hours relative gain • No gain increase in short measurements • This is not for a special batch of GEMs but for all GEMs we • produced • Possible reasons; • Less charging-up due to cylindrical hole shape • Less polarization of Liquid Crystal Polymer F. Simon (IEEE, 2006) T. Tamagawa(IEEE,2007) time (s)

8. GemGrid 1 GemGrid 2

9. Bulk high-resistivity materials hydregenated amorphous silicon allowed gains up to 5 105 staying proportional! Si-rich silicon nitride (Si3N4)

10. Measurements on Si-rich Silicon Nitride (Si3N4) Column resistance: ρ D/O Potential surface measurable: gain drop factor 2 at dV = 17.5 V With known current: bulk resistivity ρ measurable: ~ 1 – 50 1013 Ohm cm Surface time constant: Column resistance x (virtual colum capacitance) = (ρ D/O)*(ε O/D) = ρ ε(independant of layer thickness D!)

11. Resistive Plate Chambers (RPCs) • essential: high-resistivity material • - quenches sparks • - sufficient charge compensation current • Traditional: insulator + dope (Sardinian oils…?) • New: high-resistivity bulk (ceramic) material: higher counting rates • Compare graphite covered mylar foil

12. conductivity of kapton Micromegas on pillars Edge discharge protection foil discharges + vibrations

14. Charge-up effects • After (rapid) ramping of HV: • polarisation: reduction of E-field in insulator (bulk) volume • In homogeneous field with insulator // to field: nothing With E component perp. on insulating surface: modification of potential by hitting e- and/or ions until E // surface

15. GEM hole

16. equalizing with water Stronger effects for good insulator region of worse insulation

17. Very preliminary: Use as little as possible insulating surfaces // strong E fields Apply high-resistivity materials instead of insulators Even more preliminary: As for gain: GEMs perform les than (corresponding) Micromegas

18. April 2004 Micromegas + MediPix 2 NIKHEF/Saclay/Univ. Twente: 55Fe, 1s No source, 1s 55Fe Cathode (drift) plane Drift space: 15 mm Micromegas Baseplate MediPix2 pixel sensor Brass spacer block Printed circuit board Aluminum base plate 14 mm δ-ray! He/Isobutane 80/20 Modified MediPix MIPs

19. Integrate Micromegas and pixel sensor: InGrid ‘wafer post processing’ by Univ. of Twente, MESA+’

20. Full post-processing of a TimePix • Timepix chip + SiProt + Ingrid: 14 mm MESA+ “Uniform” Charge mode IMT Neuchatel

21. Drifttime (bin = 10 ns) cathode @ - 1500 V 14 mm 10 mm A “long” cosmic track Timepix + 20 μm thick Siprot + Ingrid Stable operation in He iC4H10

23. Cathode (drift) plane Si depletion layer Cluster1 Cluster2 1mm, 100V Vbias Cluster3 Integrated Grid (InGrid) CMOS chip 50um, 400V Slimmed Silicon Readout chip Input pixel 50um Si (vertex) track detector GOSSIP Gas: 1 mm as detection medium 99 % chance to have at least 1 e- Gas amplification ~ 1000: Single electron sensitive All signals arrive within 16 ns • Si strip detectors • Si pixel detectors • MAPs

24. 1.2 mm Gossip: replacement of Si tracker Essential: thin gas layer (1.2 mm)

25. GOSSIP-Brico: PSI-46 (CMS Pixel FE chip) First prototype of GOSSIP on a PSI46 is working: • 1.2 mm drift gap • Grid signal used as trigger • 30 µm layer of SiProt

26. Tracking sensor material: gas versus Si • it is light • primary electrons can simply be multiplied: gas amplification: low power • no bias current: low power & simple FE circuits • gas can be exchanged: no radiation damage of sensor • gas has a low εr: with small voxels the source capacity can be small (10 fF) • allowing fast, low-noise, and low-power preamps • gas is usually cheap • low sensitive for neutron and X-ray background • δ-rays can be recognized • [high ion & electron mobility: fast signals, high count rates are possible] • discharges/sparks: readout system should be spark proof • ageing: must be solved and must be understood / under control • diffusion: limits max. drift length

27. CMOS Chip protection against - discharges - sparks - HV breakdowns - too large signals Silicon Protection: SiProt Amorph Si (segmented) Emperical method: Try RPC technology

28. Qmax ~ 1 – 2 fC Chip may die if Qmax > 10 fC

29. Ageing Radiation damage of CMOS pixel chip is relevant - common for all tracking detectors - believed to widthstand ATLAS Upgrade Dose in 90 nm technology Radiation damage of sensor: not relevant for Gossip sensor since this is gas being exchanged Typical for gaseous detectors: the deposit of an (insulating) polymer on the electrodes of a detector. Decrease of signal amplitude • Little ageing expected: • little primary ionisation (~ 10 e-/track) • low gas gain (500 – 1000) • large anode surface (compare pixel anode plane with surface of thin wire) • E-field at flat anode ~3 lower than E-field at anode wire

30. gas: standard Ar/Methane 90/10. Deposit containing C found on anode

31. Irradiation with 8 keV X-rays:No rate effects up to anode current density of 0.2 μA / mm2 very fast track counting possible! After 0.3 Coulomb/mm2:  (eq. 3.7 x 1016 MIPs/cm2 !!) deposit of carbon polymer on anode is clearly visible. Micromegas is clean (!?) Little deposit on cathode, and…… Chamber still worked! Ageing

32. Construction of many test chambers prototypes Next-1,2,3,4,5 Next Quad Next-64 (ReNexed, ReLaXd) DICE Ageing Chambers

33. Next-64 / ReLaXd / ReNexd CO2 cooling!

34. DICE

35. Reactor Institute Delft RID DICE Nuclear Reactor Water Bassin 10 x 10 x 10 m3

37. Upgraded SCT: Gossip could replace: • Pixel vertex detector: Gossip • Si Strip detectors: replace by Gossip Strixel detectors • TRT: use Gossip as tracker/TR X-ray detector • Essentials: • power dissipation: 60 mW/cm2 • intrinsic mass: 0.1 % radiation length • low cost: 10 $ / cm2

38. Barrel SCT unit EndCap SCT unit

39. Semiconductor (pixel, strip) detectors Depleted Si, 300 μm Vbias = 150 V electron-hole pairs (pixel) chip with preamps, shapers, discriminators

40. Flex Hybrid Wire-bonding MCC Wire-bonding FE’s MCC Side view not to scale sensor bumps FE chip FE chip C-C support Flex module 2.x ATLAS pixel: basic element

41. - Ladder strings fixed to end cones • Integration of beam pipe, end cones & pixel vertex detector • 5 double layers seems feasible

42. Gossip in ATLAS (Goat-1) Stave TimePix-2 chip SiNProt layer InGrid (Si3N4) Gas Cover casted aluminium power line ‘P’(ositive)String carrying 1.3 V ‘G’(round)String gas manifold ‘Road’: C-fibre reinforced databus + aux services StainlessSteel tube for CO2 cooling Stiff, light Stave formed by G-string P-string Road triangle

43. GOAT: GOssip in ATlas Inner Layer: 7 double Goat strings Gossip readout Gossip detector unit Ø60mm Beampipe P-string conductor (+voltage) CO2 cooling channels G-string conductor (+voltage)

44. Upgraded SCT: Gossip/GridPix could replace: • Pixel vertex detector: Gossip • Si Strip detectors: replace by Gossip Strixel detectors • TRT: use GridPix as tracker/TR X-ray detector strixels/strips preamp channels ~ 20 mm • Essentials: • power dissipation: 1/16 x 60 mW/cm2 = 4 mW/cm2 • now:25 mW/cm2 • intrinsic mass: 0.1 % radiation length • low cost: 10 $ / cm2

45. Upgraded Tracker: Gossip could replace: • Pixel vertex detector: Gossip • Si Strip detectors: replace by Gossip Strixel detectors • TRT: use Gossip with 17 mm Xe layer • as tracker/TR X-ray detector • Essential: • high position-resolution tracker throughout tracker • low mass, low cost detector • Efficient TRD possible

46. Testbeam Nov 5 – 12, 2007 PS/T9: electrons and pions, 1 – 15 GeV/c L=30 mm V0 V1 f Transition Radiator 0.05 mm Anatoli Romaniouk, Serguei Morozov, Serguei Konovalov Martin Fransen, Fred Hartjes, Max Chefdeville, Victor Blanco Carballo

47. Particle Identification Samples pions (left) and electrons (right) 6 GeV/c

48. 5 (double) layer Gossip Pixel 4 layer Gossip Strixel radiator 3 layers Gossip TRT

49. Gas instead of Si • Pro: • no radiation damage in sensor: gas is exchanged • modest pixel (analog) input circuitry: low power, little space • no bias current: simple input circuit • CMOS pixel chip main task: data storage & communication (rad hard) • low detector material budget: 0.06 % radiation length/layer • typical: Si foil. New mechanical concepts • low power dissipation : little FE power (2 μW/pixel); no bias dissipation • operates at room temperature (but other temperatures are OK) • less sensitive for neutron and X-ray background • 3D track info per layer if drift time is measured • Con: • Gaseous chamber: discharges (sparks): destroy CMOS chip • gas-filled proportional chamber: ‘chamber ageing’ • Needs gas flow • Parallax error: 1 ns drift time measurement may be required

50. New mechanics + cooling concepts for Gossip • As little as possible material • detector consists of foil! • less power required ( less cooling) w.r.t. Si ‘laundry line’ ‘balloon’ string: power, chip support, cooling in 2030….