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PHOS FEE & A Large EMCal for ALICE

PHOS FEE & A Large EMCal for ALICE. ALICE Technical Board Meeting March 20,2001. Terry Awes Oak Ridge National Laboratory. Outline. US involvement in RHI @ LHC Physics with PHOS from US perspective PHOS FEE Update A Large EM Calorimeter for ALICE? Physics motivation

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PHOS FEE & A Large EMCal for ALICE

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  1. PHOS FEE & A Large EMCal for ALICE • ALICE Technical Board Meeting • March 20,2001 • Terry Awes • Oak Ridge National Laboratory

  2. Outline • US involvement in RHI @ LHC • Physics with PHOS from US perspective • PHOS FEE Update • A Large EM Calorimeter for ALICE? • Physics motivation • Conceptual design (Edward) • Installation (Edward) • Cost estimate (Edward)

  3. US-ALICE Involvement - Some History • Pre-2000: Various US efforts to obtain ALICE R&D or construction funds failed due to • RHIC budget pressures • Lack of US LHC heavy ion “program” • New Millenium: PHOS FEE Letter of Intent submitted to DOE • Received favorably by DOE, proposal encouraged • ORNL given DOE funds for PHOS FEE architecture work • BUT, no decision from DOE until after NSAC LRP recommendation on US LHC involvement • LHC-USA meeting at LBL in December to • attract interest from within LBL • prepare a LHC-USA white paper for the RHI NSAC LRP Town Meeting at BNL January 2001

  4. NSAC Long Range Plan Update (from Glenn Young) • The LHC “white paper” was handed in at the January Town Meeting at BNL • It will go in the writeup, both Physics and Resources • Ludlam/Ullrich/Young (responsible for “Resources” section) suggest $10M, 50 people, 2001-2006 timescale for initial effort • Organizers insisted on “modest” and “limited scope” in writeup • The LRP meeting has to “bless” the effort • March 25-31 in Santa Fe, NM; J. Symons • Huge resources competition • RIA $885M, Jlab-12GeV $150M, RHIC short-term $25M, ORLAND $60M, longer-term RHIC desires $200-300M • Symons feels it is “automatic” under “International Efforts” • McLerran, Mueller (both), Shuryak, Seto all favorable • Fillippone, Milner felt level of effort “not a problem” • DOE (Kovar, Steadman, Simon) have made it clear LHC must address physics RHIC does not.

  5. The LHC vs RHIC Physics Case • Quark-Gluon Matter at LHC will be different than QGM at SPS or RHIC - higher T, higher e, far above ec , longer t • Initial state dominated by low x processes • shadowing and saturation effects • Not pQCD, BUT calculable as hdQCD • Expect Hydrodynamics almost certainly valid - Calculable final state • We will have the usual QGP probes and signatures… • PLUS, new large Q2 probes - g, jets, upsilon, W, Z,… which allow to investigate the initial state (penetrating probes, g ), as well as the final state (strongly interacting probes, jet propagation)

  6. Physics with PHOS • High pT QCD g’s • > gluon structure functions (gluon saturation) • High precision, high pT, p0 measurement • > jet quenching (leading particle) • g-jet tagging • > jet quenching • “Low” pTg’s • > Initial QGP temperature • High energy e+/- • > W,Z production low x, high Q2, quark structure functions

  7. High pT QCD g and p0 in PHOS • One ALICE year, 25% Central, s1/2 =5.5 TeV • p0 scaled by <pT> and mult. • Direct g scaled as f(xT)/s2 • Gluon structure functions • Compton: g+q ->g+q • (gluon saturation)

  8. PHOS High pT Trigger • 25% Central Trigger rate 2000Hz • TPC data rate 20Hz • Factor 100 loss of g statistics without high pTg (e) trigger • For few Hz trigger rate need to trigger at E~ 8-10 GeV • If trigger at L3, then no TPC and no g+jet information • Need L1 high pT g trigger!

  9. Thermal Direct Photons in PHOS • 25% Central Pb+Pb • s1/2 =5.5 TeV, dNch/dy=3750 • Comparison of Decay g • to thermal g • Hydro Calculation using • Aurenche rates, • t0=0.1 fm/c

  10. W,Z Production in ALICE • Min bias Pb+Pb • (PYTHIA pn scaled to Pb+Pb) • Unique information on • quark structure functions • at low x, high Q2 in nuclei. • W+ (ud), W-(du), • ~500K W e+/- in TPC, x~0.01 • ~20K in PHOS

  11. jet Collision axis g g-Tagged jets: E-Loss/Jet Fragmentation • Direct g-tagged events: Eg~Ejet • Measure Dh/a(z) • Compare AA to pp X.-N.Wang&Huang PRC55(97)3047

  12. High Energy g Measurements with PHOS • Problem of Nuclear Counter effect in Photodiode • Increase Crystal Length from 18 to 22 cm - possible • Use Avalanche Photodiodes (CMS) - good test beam results • Need high energy g trigger at L1 if want TPC readout with g event

  13. PHOS Electronics (ORNL project) • Photodiode or Avalanche Photodiode Readout • 18,000 channels • 100 GeV Max, Least Count = 3 MeV • 15 bits effective - dual gain range 11 bits separated by 16 • High energy shower trigger for L1 (overlapping tiles) • Time measurement for neutron/antineutron rejection • Based on WA98 and PHENIX EMCal electronics • Estimated total cost ~$4M (~$1M Production)

  14. PHOS FEE Block Diagram Analog Data SHAPER CARD Preamps DIODES Setup 8 FEM Digital Data Total of 8 Shaper Cards Setup, Timing, Trigger From TTC DCM layer 1 64 Channels Digital Data To RORC Total of 8 FEM Setup, Timing, Trigger DCM layer 2 512 Channels To Trig Total of 8 DCM layer 1 Concept for ALICE PHOS Front End Electronics Alan Wintenberg 4096 Channels

  15. Shaper/Amplifier Chip (8 channels) Concept for ALICE PHOS Shaper Electronics Alan Wintenberg

  16. FEM Board Block Diagram Concept for ALICE PHOS FEM Electronics Alan Wintenberg

  17. DMU and Trigger Chip (8 channels) Concept for ALICE PHOS DMU and trigger chip Alan Wintenberg

  18. Data Collection Module - Layer 1 (512 channels) DATA DATA SER DES DATA BUFFER SER DES TT&C TT&C TRIGGER IN TRIGGER OUT TT&C MUX or FANOUT CONTROL LOGIC from 8 FEMs To/From DCM Layer 2 DATA SER DES TT&C TRIGGER LOGIC (OR) TRIGGER IN TT&C= Timing, Trigger and Control Concept for ALICE PHOS Data Collection Module (Layer 1) Alan Wintenberg

  19. Data Collection Module - Layer 2 (4096 channels) DDL DATA DATA To RORC SER DES DATA BUFFER SIU TT&C TRIGGER IN TT&C MUX or FANOUT CONTROL LOGIC To TTC TTCrx from 8 DCM layer 1’s DATA LVL-0, etc. SER DES TT&C To/From ALICE Trigger Rack TRIGGER LOGIC (OR) TRIGGER OUT TRIGGER IN TT&C= Timing, Trigger and Control Concept for ALICE PHOS Data Collection Module (Layer 2) Alan Wintenberg

  20. WA98 PbGlass FEE Costing • 10080 channels of leadglass, FEU-84 PMTs • Features (stop&read architecture, 1 kHz) • Two gain ranges (*8; 10-bit ADC) • CFD+TAC • AMU-ADC/ TAC-ADC • 2x2/4x4 trigger (1 threshold) • Contributions (June 1992 - November 1994) • ORNL (architecture, designs, chips, firmware) $0.8M • U. Lund (boards, parts, assembly) $0.3M • GSI (chip fabrication) $0.2M • U. Muenster (DCMs) $0.1M • TOTAL = $1.4M direct funding; also $0.2M small-item capital

  21. PHENIX EMCal FEE Costing • 9216 channels of PbGlass, 15552 of PbScint • Features (pipelined architecture, 25 kHz) • Two gain ranges (*16; 12-bit ADC) • CFD/LED+TAC • AMU/ADC (fully pipelined, simultaneous read/write) • 2x2/4x4 trigger (4 thresholds: 3 of 4x4, 1 of 2x2) • Contributions (May 1995 - February 2000) • ORNL (everything: architecture, design, fab, testing) • chip fabrication $0.2M • Board fabrication $0.9M • Also $0.2M of small-items capital • DOE $2.0M, RIKEN $0.4M = $2.4M total

  22. Rough Estimate of PHOS FEE Costs • Engineering • ASICs: 4 FTE-years of I&C engineer $1.2M • Boards: 1 FTE-year I&C engineer $0.3M • FPGA firmware, test software: 2 FTE-years I&C engineer $0.6M • ASIC teststands, software: $0.4M • ASIC fabricate, package, test: $0.4M • boards design, prototypes $0.3M • Fabricate 20K channels (except ASICs): $0.8M • Assume ORNL Physics contributes $150K capital (DAQ, software, testing, small items) • TOTAL = $4.1M

  23. Near Term Plans • The LHC-USA “community” will submit a Letter of Intent to the DOE by end of March which will describe present plans for US involvement in LHC heavy ion program. Main emphasis will focus on “Hard Processes” according to expected recommendation of Long Range Plan. • Highlights of LoI: • PHOS electronics project (proposal to accompany/follow) • Interest to develop a proposal for a Large EMCal for PHOS • ALICE L3 trigger effort • CMS participation (software/analysis only) • Computing for CMS/ALICE

  24. A Large Coverage EM Calorimeter for ALICE • TOP VIEW • Two Arms around TPC Barrel, (~10 x PHOS) • Dy = +/- 0.7, Df = 80O , Dfsep = 80O • Encaps: (~10 x PHOS each) • 0.7 < y < 1.5, Df = 360O

  25. A Large Coverage EM Calorimeter for ALICE • END VIEW • Two Arms around TPC Barrel (one shown), (~10 x PHOS) • Dy = +/- 0.7, Df = 80O , Dfsep = 80O • Encaps (not shown): (~10 x PHOS each) • 0.7 < y < 1.5, Df = 360O

  26. Advantages of Large EM Calorimeter • Increased yield (pT coverage) for g, p0, and e (20-30 x PHOS) • Back-to-back g-g coincidences. Strong kinematic constraints for pdf’s information (qqbar annihilation and gluon fusion). • Z measurement via e+e- • Jet physics program: • Full EM+Hadronic decomposition of jets (fragmentation studies) • g + jet (or leading particle) in TPC • p0 (leading particle) + jet in TPC • g + p0 , p0 + p0 in Calorimeter • Fast, clean, accurate trigger for high pTg , p0 , electrons • Improved high pT electron identification

  27. Assumptions for Rate Calculations • Luminosity: 1 x 1027 cm-1 s-1 Pb+Pb • > 8000 Hz Min. Bias. • One ALICE year = 30 days, 100% duty factor • TPC acceptance: Dy = +/- 0.9, Df = 360O • PHOS acceptance: Dy = +/- 0.12, Df = 100O • Large EMCal (~20 times PHOS) • Two EMCal Arms: Dy = +/- 0.7, Df = 80O , Dfsep = 80O • Single Endcap: 0.7 < y < 1.5, Df = 360O

  28. High pT QCD Direct g • One ALICE year Min Bias • PYTHIA compared to • CDF Direct g • Gluon structure functions • Compton: g+q ->g+q • (gluon saturation)

  29. QCD Direct g + g • One ALICE year Min Bias • PYTHIA • Structure functions • Fusion: g+g ->g + g(gluon saturation) • Annih: q+qbar ->g + g

  30. jet Collision axis g g-Tagged jets: E-Loss/Jet Fragmentation • Direct g-tagged events: Eg~Ejet • Measure Dh/a(z) • g in PHOS, ARMs, ENDCAP • q,g jet into TPC acceptance X.-N.Wang&Huang PRC55(97)3047

  31. Z, g*Production in ALICE - electron pairs • Min bias Pb+Pb • (PYTHIA pn scaled to Pb+Pb) • Unique measurement of • quark structure functions • at low x, high Q2 in nuclei. • Z (uu,dd) • ~50K Z e+/- in TPC • Better kinematic constraints (on x) by measuring pairs.

  32. W Production in ALICE • Min bias Pb+Pb • (PYTHIA pn scaled to Pb+Pb) • Unique measurement of • quark structure functions • at low x, high Q2 in nuclei. • W+ (ud), W-(du), • ~500K W e+/- in TPC, x~0.01 • (similar rate for m in muon spec. x~.0003) , • 20K in PHOS

  33. Z Production in ALICE • Min bias Pb+Pb • (PYTHIA pn scaled to Pb+Pb) • Unique measurement of • quark structure functions • at low x, high Q2 in nuclei. • Z (uu,dd) • ~50K Z e+/- in TPC • Better kinematic constraints (on x) by measuring pairs.

  34. LHC parton kinematics • For W, Z production x = (M/5500 GeV) exp(-y) • For g production at y=0 • x = pT/5500 GeV • e.g. x = 0.002 • @ pT=10 GeV/c

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