R&D for Future Detectors

1. R&D for Future Detectors Detector R&D continues on many fronts Future Detectors will include: • Neutrino detectors • Massive, high efficiency • Hadron B Factory, Rare Kaon Decay, /Charm Detectors • High bandwidth, high precision • Linear Collider Detectors • Precision measurements I will concentrate on the Linear Collider Detector R&D J. Brau - ICHEP 2004 - R&D for Future Detectors

2. Linear Collider Detector Requirements Both Physics and Accelerator Constraints dictate the Detector Requirements Linear Collider creates new challenges and opportunities, different in many respects from the challenges and opportunities of the LHC detectors Physics motivates Triggerless event collection (software event selection) Extremely precise vertexing Synergistic design of detectors components: vertex detector, tracker, calorimeters integrated for optimal jet reconstruction New technologies based on recent detector inventions Detector R&D of Next Few Years is Critical J. Brau - ICHEP 2004 - R&D for Future Detectors

3. Collider Constraints Linear Collider Detector R&D has had to consider two different sets of collider constraints: X-Band RF and Superconducting RF designs With the linear collider technology selection, the detector efforts can concentrate on one set of parameters The ILC creates requirements similar to those of the TESLA design J. Brau - ICHEP 2004 - R&D for Future Detectors

4. t t event at 350 GeV Linear Collider Events • Simple events (relative to Hadron collider) make particle level reconstruction feasible • Heavy boson mass resolution requirement sets jet energy resolution goal J. Brau - ICHEP 2004 - R&D for Future Detectors

5. Neutral Hadrons EM Charged Hadrons ~ 20% / E Calorimetry Current paradigm: Particle/Energy Flow (unproven) • Jet resolution goal is 30%/E • In jet measurements, use the excellent resolution of tracker, which measures bulk of the energy in a jet Headroom for confusion J. Brau - ICHEP 2004 - R&D for Future Detectors

6. Energy/Particle Flow Calorimetry Follow charged tracks into calorimeter and associate hadronic showers Identify EM clusters not associated with charged tracks (gammas) Remaining showers will be the neutral hadrons J. Brau - ICHEP 2004 - R&D for Future Detectors

7. EM Calorimetry • Physics with isolated electron and gamma energy measurements require ~10-15% / E  1% • Particle/Energy Flow requires fine grained EM calorimeter to separate neutral EM clusters from charged tracks entering the calorimeter • Small Moliere radius • Tungsten • Small sampling gaps – so not to spoil RM • Separation of charged tracks from jet core helps • Maximize BR2 • Natural technology choice – Si/W calorimeters • Good success using Si/W for Luminosity monitors at SLD, OPAL, ALEPH • Oregon/SLAC/BNL • CALICE • Alternatives – Tile-Fiber (challenge to achieve required granularity) Scintillator/Silicon Hybrid Shaslik Scintillator Strip J. Brau - ICHEP 2004 - R&D for Future Detectors

8. Silicon/Tungsten EM Calorimeter • SLAC/Oregon/BNL • Conceptual design for a dense, fine grained silicon tungsten calorimeter well underway • First silicon detector prototypes are in hand • Testing and electronics design well underway • Test bump bonding electronics to detectors by end of ’04 • Test Beam in ’05 J. Brau - ICHEP 2004 - R&D for Future Detectors

9. Silicon/Tungsten EM Calorimeter (2) • Pads ~5 mm to match Moliere radius • Each six inch wafer read out by one chip • < 1% crosstalk • Electronics design • Single MIP tagging (S/N ~ 7) • Timing < 5 nsec/layer • Dynamically switchable feedback capacitor scheme (D. Freytag) achieves required dynamic range: 0.1-2500 MIPs • Passive cooling – conduction in W to edge Angle subtended by RM GAP J. Brau - ICHEP 2004 - R&D for Future Detectors

10. ECAL Prototype 9720 channels in prototype J. Brau - ICHEP 2004 - R&D for Future Detectors

11. Wafers: Russia/MSU and Prague/IOP beam Tilt  X ECAL  Y HCAL PCB: LAL design, production – Korea/KNU Preparations for DESY Beam Test …DESY late 2004 J. Brau - ICHEP 2004 - R&D for Future Detectors

12. Other EM Calorimeters • Tile-fiber • Interesting readouts, such as SiPM • Option – shower max (scintillator strips or silicon pads) Russia, ITEP KEK, Kobe, Konan, Niigata, Shinshu, Tsukuba Silicon Photomultiplier Colorado J. Brau - ICHEP 2004 - R&D for Future Detectors

13. Sc-W-Sc-W-Si-W-Sc-W-Sc-W Como, ITE-Warsaw, LNF, Padova, Trieste Kansas Other EM Calorimeters (2) • Silicon-scintillator Hybrid • Scintillator strip • Shashlik KEK, Kobe, Konan, Niigata, Shinshu, Tsukuba J. Brau - ICHEP 2004 - R&D for Future Detectors

14. Hadron Calorimetry • Role of Hadron Calorimetry in the Energy/Particle Flow • Isolate and measure neutral hadrons • Approaches Technology • RPCs (Note promising work at IHEP-Beijing on oil-less resistive plate) • GEMs • Tile-fiber w/ APD SiPM HPD EBCCD • Scintillator strips Readout • Analog • Digital – high granularity J. Brau - ICHEP 2004 - R&D for Future Detectors

15. MINICAL Prototype • Studied different readout systems (PM, SiPM, APD) • Established reliable calibration system, checked long term stability, established detailed MC simulation • Developed stability monitoring system Electron resolution in hadron calorimeter In 2005 move to hadron beam to fully test HCAL performance Hamburg, DESY, Dubna, MEPhI, Prague, LPI, ITEP J. Brau - ICHEP 2004 - R&D for Future Detectors

16. Digital Hadron Calorimetry • 1 m3 prototype planned to test concept • Lateral readout segmentation: 1 cm2 • Longitudinal readout segmentation: layer-by-layer • Gas Electron Multipliers (GEMs) and Resistive Plate Chambers (RPCs) evaluated • Objectives • Validate RPC approach (technique and physics) • Validate concept of the electronic readout • Measure hadronic showers with unprecedented resolution • Validate MC simulation of hadronic showers • Compare with results from Analog HCAL J. Brau - ICHEP 2004 - R&D for Future Detectors

17. Tracking • Tracking for any modern experiment should be conceived as an integrated system, combined optimization of: • the inner tracking (vertex detection) • the central tracking • the forward tracking • the integration of the high granularity EM Calorimeter • Pixelated vertex detectors are capable of track reconstruction on their own, as was demonstrated by the 307 Mpixel CCD vertex detector of SLD, and is being planned for the linear collider • Track reconstruction in the vertex detector impacts the role of the central and forward tracking system J. Brau - ICHEP 2004 - R&D for Future Detectors

18. Inner Tracking/Vertex Detection Detector Requirements • Excellent spacepoint precision ( < 4 microns ) • Superb impact parameter resolution ( 5µm  10µm/(p sin3/2) ) • Transparency ( ~0.1% X0 per layer ) • Track reconstruction ( find tracks in VXD alone ) Concepts under Development for Linear Collider • Charge-Coupled Devices (CCDs) • demonstrated in large system at SLD • Monolithic Active Pixels – CMOS (MAPs) • DEpleted P-channel Field Effect Transistor (DEPFET) • Silicon on Insulator (SoI) • Image Sensor with In-Situ Storage (ISIS) • HAPS (Hybrid Pixel Sensors) J. Brau - ICHEP 2004 - R&D for Future Detectors

19. SLD VXD3 307 Mpixels 5 MHz  96 channels 0.4% X0 / layer ~15 watts @ 190 K 3.9 m point res. av. - 2 yrs and 307 Mpxl Inner Tracking/Vertex Detection (CCDs) Issues • Readout speed and timing • Material budget • Power consumption • Radiation hardness R&D • Column Parallel Readout • ISIS • Radiation Damage Studies J. Brau - ICHEP 2004 - R&D for Future Detectors

20. Column Parallel CCD SLD Vertex Detector designed to read out 800 kpixels/channel at 10 MHz, operated at 5 MHz => readout time = 200 msec/ch Linear Collider demands 250 nsec readout for Superconducting RF time structure Solution: Column Parallel Readout LCFI (Bristol, Glasgow, Lancaster, Liverpool, Oxford, RAL) (Whereas SLD used one readout channel for each 400 columns) J. Brau - ICHEP 2004 - R&D for Future Detectors

21. Column Parallel CCD (2) Next Steps for LCFI R&D • Bump bonded assemblies • Radiation effects on fast CCDs • High frequency clocking • Detector scale CCDs w/ASIC & cluster finding logic; design underway – production this year • In-situ Storage Devices • Resistant to RF interference • Reduced clocking requirements J. Brau - ICHEP 2004 - R&D for Future Detectors

22. Image Sensor with In-situ Storage (ISIS) • EMI is a concern (based on SLC experience) which motivates delayed operation of detector for long bunch trains, and consideration of ISIS • Robust storage of charge in a buried channel during and just following beam passage (required for long bunch trains) • Pioneered by W F Kosonocky et al IEEE SSCC 1996, Digest of Technical Papers, 182 • T Goji Etoh et al, IEEE ED 50 (2003) 144; runs up to 1 Mfps. • charge collection to photogate from 20-30 mm silicon, as in a conventional CCD • signal charge shifted into stor. register every 50ms, providing required time slicing • string of signal charges is stored during bunch train in a buried channel, avoiding charge-voltage conversion • totally noise-free charge storage, ready for readout in 200 ms of calm conditions between trains for COLD LC design • particles which hit the storage register (~30% area) leave a small ‘direct’ signal (~5% MIP) – negligible or easily corrected J. Brau - ICHEP 2004 - R&D for Future Detectors

23. Radiation Effects in CCDs N. Sinev et al. • Drift of charge over long distance in CCD makes detector very susceptible to effects of radiation: • Transfer inefficiency • Surface defects Traps can be filled • neutrons induce damage clusters • low energy electrons create point defects – but high energy electrons create clusters – Y. Sugimoto et al. • number of effective damage clusters depends on occupation time – some have very long trapping time constants – modelled by K. Stefanov Hot pixels • Expect ~1.5x1011/cm2/yr of ~20 MeV electrons at layer-1 • Expect ~109/cm2/yr 1 MeV-equivalent dose from extracted beamline J. Brau - ICHEP 2004 - R&D for Future Detectors

24. Inner Tracking/Vertex Detection (MAPs) R&D • Strasbourg IReS has been working on development of monolithic active pixels since 1989; RAL also now. • First IReS prototype arrays of a few thousands of pixels demonstrated the viability of technology and its high tracking performances. • First large prototypes now fabricated and being tested. • Current attention focussed on readout strategies adapted to specific experimental conditions. Parallel R&D: FAPS (RAL) • 10-20 storage capacitors/pixel Concept • Standard VLSI chip, with thin, un-doped silicon sensitive layer, operated undepleted Advantages • decoupled charge sensing and signal transfer (improved radiation tolerance, random access, etc.) • small pitch (high tracking precision) • Thin, fast readout, moderate price, SoC Technology will be used at STAR J. Brau - ICHEP 2004 - R&D for Future Detectors

25. Inner Tracking/Vertex Detection (DEPFET) Properties • low capacitance ►low noise • Signal charge remains undisturbed by readout ►repeated readout • Complete clearing of signal charge ►no reset noise • Full sensitivity over whole bulk ► large signal for m.i.p.; X-ray sens. • Thin radiation entrance window on backside ► X-ray sensitivity • Charge collection also in turned off mode ► low power consumption • Measurement at place of generation ► no charge transfer (loss) • Operation over very large temperature range ► no cooling needed Concept • Field effect transistor on top of fully depleted bulk • All charge generated in fully depleted bulk; assembles underneath the transistor channel; steers the transistor current • Clearing by positive pulse on clear electrode • Combined function of sensor and amplifier 16x128 DEPFET-Matrix MPI Munich, MPI Halle, U. Bonn, U. Mannheim J. Brau - ICHEP 2004 - R&D for Future Detectors

26. Central Tracking • Two general approaches being developed for the Linear Collider TPC (or Jet Chamber) • Builds on successful experience of PEP-4, ALEPH, ALICE, DELPHI, STAR, ….. • Large number of space points, making reconstruction straight-forward • dE/dx  particle ID, bonus • Minimal material, valuable for calorimetry • Tracking up to large radii Silicon • Superb spacepoint precision allows tracking measurement goals to be achieved in a compact tracking volume • Robust to spurious, intermittent backgrounds • linear collider is not storage ring J. Brau - ICHEP 2004 - R&D for Future Detectors

27. Central Tracking (TPC) Issues for LC TPC • Optimize novel gas amplification systems • Conventional TPC readout based on MWPC and pads • limited by positive ion feedback and MWPC response • Improvement by replacing MWPC readout with micropattern gas chambers (eg. GEMs, Micromegas) • Small structures (no EB effects) • 2-D structures • Only fast electron signal • Intrinsic ion feedback suppression • Neutron backgrounds • Optimize single point and double track resolution • Performance in high magnetic fields • Demonstrate large system performance with control of systematics J. Brau - ICHEP 2004 - R&D for Future Detectors

28. TPC Gas Amplification System New concept for gas amplification at the end flanges: Replace proportional wires with Micro Pattern Gas Detectors • Gas Electron Multiplier (GEM) - F. Sauli, 1997 • or Micromegas - Y. Giomataris et al., 1996 GEM Conventional TPC: Wires Small structures (no EB effects) 2-D structures Only fast electron signal Intrinsic ion feedback suppression Also being investigated: Medipix2, CMOS pixel sensor w/GEM (NIKHEF, Saclay, Twente/Mesa, CERN) J. Brau - ICHEP 2004 - R&D for Future Detectors

29. 140 m 75 m Gas Electron Multiplier (GEM) for TPC Readout • 50 µm kapton foil, • double sided copper coated • 75 µm holes, 140 µm pitch • GEM voltages up to 500 V • yield 104 gas amplification Use GEM towers for safe operation (COMPASS) J. Brau - ICHEP 2004 - R&D for Future Detectors

30. 50 mm pitch Micromegas for TPC Readout • asymmetric parallel plate chamber • with micromesh • saturation of Townsend coefficient • mild dependence of amplification • on gap variations • ion feedback suppression J. Brau - ICHEP 2004 - R&D for Future Detectors

31. TPC Resolution Studies with Magnetic Field and 1 T at Triumf J. Brau - ICHEP 2004 - R&D for Future Detectors

32. Ion feedback improves with (GEM) or is independent of (Micromegas) magnetic field transverse resolution (mm) B = 0 B = 0.9 T 100 micron B = 1.5 T 30 mm 300 mm drift time (50 ns bins) TPC Resolution TPC Resolution and Ion Feedback GEM Magnetic field improves resolution P5 gas Double-GEM J. Brau - ICHEP 2004 - R&D for Future Detectors

33. Central Tracking (Silicon) With superb position resolution, compact tracker is possible which achieves the linear collider tracking resolution goals Compact tracker makes the calorimeter smaller and therefore cheaper, permitting more aggressive technical choices (assuming cost constraint) Linear Collider backgrounds (esp. beam loss) extrapolated from SLC experience also motivate the study of silicon tracking detector, SiD Silicon tracking layer thickness determines low momentum performance 3rd dimension may be achieved with segmented silicon strips, or silicon drift detectors (1.5% / layer) (TPC) J. Brau - ICHEP 2004 - R&D for Future Detectors

34. Central Tracking (Silicon) • Optimizing the Configuration support Cooper, Demarteau, Hrycyk R. Partridge H. Park J. Brau - ICHEP 2004 - R&D for Future Detectors

35. Power Off Power On 60 msec power restoration 8 msec power-off period (not to scale) Response to ¼, 1 and 4 mip signals Central Tracking (Silicon) • Strip length: • Short strips segments (10 cm slices) are interesting for less noise, shorter shaping time, better time stamping. • Longer strips, long shaping time designs are also under development, motivated by minimized material in tracking volume. • Two ASICs for long shaping will soon go to fab. Santa Cruz ASIC power cycle LPNHE Preamp Note, silicon detector R&D also supports TPC detector where intermediate and forward tracking are needed J. Brau - ICHEP 2004 - R&D for Future Detectors

36. Silicon Tracking w/ Calorimeter Assist Primary tracks started with VXD reconstr. V0 tracks reconstructed from ECAL stubs E. von Toerne J. Brau - ICHEP 2004 - R&D for Future Detectors

37. Very Forward Instrumentation • Hermiticity depends on excellent coverage in the forward region, and forward system plays several roles • maximum hermiticity • precision luminosity • shield tracking volume • monitor beamstrahlung • High radiation levels must be handled • 10 MGy/year in very forward detectors TESLA Goal: ΔL/L: 10-4 (exp.) ΔL/L: 10-4 (theo.) Ref: OPAL (LEP) ΔL/L: 3.4 x 10-4 (exp.) ΔL/L: 5.4 x 10-4 (theo.) J. Brau - ICHEP 2004 - R&D for Future Detectors

38. Machine Detector Interface • A critical area of detector R&D which must be optimized is where the detector meets the collider • Preserve optimal hermiticity • Preserve good measurements • Control backgrounds • Quad stabilization Zero crossing angle, TPC detector 20 mr crossing angle, silicon detector J. Brau - ICHEP 2004 - R&D for Future Detectors

39. Detector Beamline Instrumentation • Polarized electrons (and perhaps positrons) • Polarimeter • 0.2% goal • Electron energy • Energy spectrometer • 200 ppm required • Beam energy profile • Differential luminosity measurement • knowledge of beamstrahlung effects required S. Boogert J. Brau - ICHEP 2004 - R&D for Future Detectors

40. Other Detector R&D Efforts • Muon Detectors • RPCs • Scintillator strips w/ MAPMTs • Detector Solenoid • All detector concepts under study assume a strong magnetic field of strength greater than 3T with a coil of large diameter. • The large volume required for this high-field magnet is a challenge, but experience with the 4T solenoid for CMS will be very helpful. • This experience has been utilized in detector designs, but requires additional understanding. • Need to study compensation issues if machine has a crossing angle. • Quad stabilization • Machine-detector-interface issue crucial for the detector. J. Brau - ICHEP 2004 - R&D for Future Detectors

41. Summary • Linear Collider Experimental Program needs advances in detector technology specific to the challenges of the LC: • High granularity, high precision, triggerless operation • A coordinated, R&D effort is underway world-wide to develop the advanced detectors needed to capitalize on the special discovery opportunities which will be created by the construction of the linear collider. • The Detector community has been preparing, but eagerly awaiting the technology choice to make the focused R&D program. With the technology decision, it is now time for a significant ramping up of this effort. J. Brau - ICHEP 2004 - R&D for Future Detectors