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Trigger Upgrades to the PHENIX Muon Arms. Mickey Chiu University of Illinois at Urbana-Champaign for the Forward Upgrade Group. Quark Flavor Structure Measurement at RHIC. , X a >>X b. D. , X b >>X a. d. (. x. ). +. =. b. A. (. W. ). L. ). d. x. (. b. Polarised PDF
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Trigger Upgrades to the PHENIX Muon Arms Mickey Chiu University of Illinois at Urbana-Champaign for the Forward Upgrade Group
Quark Flavor Structure Measurement at RHIC , Xa>>Xb D , Xb>>Xa d ( x ) + = b A ( W ) L ) d x ( b Polarised PDF Asymmetry Analysis Collaboration M. Hirai, S. Kumano and N. Saito, PRD (2004) • Parity violating single-spin asymmetries at RHIC provide direct access to the quark flavor structure of the proton spin: forward rapidities
Nuclear Physics B666(2003)31-55 RHICBOS predicted Sensitivity at RHIC • PHENIX • central arm: |η|<0.35, ∆f=p, electron • Muon arm: 1.2<|η|<2.4, ∆f=2p, muon GS-A,B GRSV valence
Spin Average Sea Quark Asymmetry • pQCD implies that u(x)~d(x) • Non-perturbative processes seem to be needed in generating the sea • W+/W- measures sea asymmetry
BLUE = 600 μm RED = 300 μm BLACK = 150 μm Phenix muon arm Requirements for W Analysis • Ability to Trigger within DAQ Bandwidth • Assign Track to Right Crossing (timing) • Reasonable Momentum Resolution / Correct Sign Determination • How to identify muons from W?
Why do We need to Upgrade Muon Trigger Wei Xie • uIDLL1 rejection factor from simulation at sqrt(500)GeV, i.e. perfect shielding is ~500 • uIDLL1 rejection factor from RUN3 p-p data is ~250w/o shielding • expected rates in the future 500GeV run is 12MHz, i.e. ~16KHz w/o shielding and 50KHz w/ perfect shielding for single deep muon trigger. • PHENIX bandwidth: 12KHz (or 24 kHz with additional $2M) • W sample is about 104 for the 800pb-1 luminosity. (can’t be pre-scaled!) • need additional rejection of 20-50 depending on the beam background trigger rate, i.e. target RF: 104
Trigger Cut Backgrounds to the W Measurement • Charged hadron rejection through absorber • ~100 • More rejection from the shower profile on the tube. • More rejection from isolation cut: ~5 Charged hadron through absorber Total rejection: ~103 Major background from the pion punch through and Z0 decay. Measurement: pT>20GeV/c Still to Consider: • Cosmic Background • Punch Through and Decays • low p hadrons look like high p
Sagitta<=1 strip Sagitta<=2 strips Sagitta<=3 strips efficiency Trigger Option I: MuTr FEE Upgrade Solution m+ m- A birds eye view Result from Kazuya Aoki • Enough rejection power with good efficiency for high pT muons • Timing Resolution ~ 100 ns?
MuTr FEE R&D in KyotoDecember 10, 2004 Naohito Saito Kyoto / RBRC / RIKEN
Major changes in our strategy • In the meeting at LANL, splitting signal with transformer is suggested. • Advantages: Current FEE stays in • No need of heavy commissioning • Minimal cost for the installation • Concerns • Space • Transformer in high field??? • Shield with multi-layer shielding metal (suggested by T. Wise) • Air-core is tried : works, but space?? • How pulse shape would be deformed? • Decided to work-out transformer option with ASD option as a fall-back position
~1usec CPA BBCLL1 (3 mV/fC) GL1 MuIDLL1 Analog out additional gain x 8 shaper Modified ATLAS ASD Hit pattern PA FPGA (MuTrLL1) MA Discri 0.8mV/fc ~80nsec MuTr FEE – proposed modification AMU ADC MuTr Cathode DCM
Signal from Chamber Analog Output Digital Output (LVDS) ASD Chip Test Board (ver 1) 8Chips on board 4Channels / Chip Analog out Gain 0.8mV/fC Integration Time 80nsec LVDS Digital out
Signal Digital out LVDS Analog out 5mV/div 200nsec/div
Read Out Schematic • HV 1900V • Gas mixture • Ar:CO2:CF4=50%:30%:20% • Oscilloscope Termination 10Kohm • Transformer is handmade : Air-core • Similar with Ferrite core • Vmain & Vsub have • the same pulse shape
ASD Digital Output 1V/div ASD Analog Output (Signal of Sub Line) Main Line Signal 5mV/div Time Scale 1usec/div Get Digital Signal • We could get the Digital Output • Without Distortion of Main Line Signal
Noise of Main Line Causes Fake Trigger Noise of Main Line Perfect!! Effect of Noise • Sub Line Signal is easily affected by Main Line Noise
Test stand with VDCs in Kyoto Cosmic Ray VDC • VDCs to provide space points at MuTr Chamber • Position dependence of cathode signal will be studied • if successful, position resolution will be studied Muon Tracker VDC
Trigger Option II: pad chamber solution Muon road ID ()=angle I – angle II: momentum cut
Segmentation Chun Zhang North South distance between two closet hits as a function of r at 95% probability • For Trigger, Need ~ 1 phi segmentation, and very little theta segmentation • Possibility that we might be able to improve pattern recognition in Heavy Ion Collisions simultaneously • Final Segmentation (8640 channels/plane) • adds ~ $300K in electronics cost • Smaller Pads at inner radius • e.g., for RPC1, inner pad is 2 cm and outermost pad is 9 cm 360 () X 24 ()
Forward Muon Trigger Upgrade Idea • RPCs (3d space points) for Momentum at Trigger Level • Instrument MuTr cathodes with trigger electronics (Kyoto) W-candidate@(Level-1) = MUID-Road &∆Φ|RPC& p>pcut
Development of a Fast Muon Trigger to Study the Quark-Gluon Structure of the Proton $2 Million NSF MRI Proposal
Current collaborators on W-project University of Colorado Frank Ellinghaus, Ed Kinney, Jamie Nagle, Joseph Seele, Matt Wysocki University of California at Riverside Ken Barish, Stefan Bathe, Tim Hester, Astrid Morreale, Richard Seto, Alexander Solin University of Illinois at Urbana Champaign Mickey Chiu, Matthias Grosse Perdekamp, Hiro Hiejima, Naomi Makins, Jen-Chieh Peng, Ralf Seidl, Chris Prokop, John Koster, Aaron Veicht Iowa State University John Lajoie, John Hill, Gary Sleege Kyoto University Kazuya Aoki, Ken-ichi Imai, Naohito Saito, Kohei Shoji Columbia University Cheng Yi Chi, William Zajc RBRC Gerry Bunce, Wei Xie Abilene Christian University Rusty Towell, Larry Isenhower Peking University Yajun Mao, Ran Han, Hongxue Ye, Hongtao Liu
Single Gap RPCs (CMS style design) Pick-up cathodes and FEE • The chamber structure: • Gap: 2 mm; • HV electrodes : 100 m graphite • Gas pressure : ~1 Atm • Gas mixture: ~95%F134a, ~4.5%Iso-Butane, 0.5%SF6; • bakelite resistivity 10 10- 10 12cm • 2-3kHz/cm2 in avalanche mode!
From Yong Ban Basics of Resistive Plate Chamber: working mode • Avalanche: The electric field is such that the electron energy is larger than the ionising potential • The separation avalanche-streamer decreases with increasing HV . • CMS-RPC will work at avalanche mode, to ensure the proper operation at very high rate. • RPC has been used in L3, ARGO-YBJ,Belle, BaBar experiments. • all 4 LHC experiments will use RPC for muon system.
Cost + Schedule • 2005 First Prototype Test in Run05 Beam • Full scale prototype plus electronics • Winter 2006 Test of Full scale prototype in Run07 • 2007-2008 Production of all planes and electronics • Summer 2007 Installation in South Muon Arm RPC Trigger • Winter 2007 Commissioning of South RPC Trigger in Run08 • Summer 2008 Installation of North Muon Arm RPC Trigger • Winter 2008 Commissioning of North RPC Trigger in Run09 • Run09 High Luminosity s = 500 GeV p+p Run
The Structure of Prototype Yajun Mao, Ran Han, PKU PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
Top View of A Single Chamber Yajun Mao, Ran Han, PKU • Material: 2mm bakelite • ( 2~3 × 1011 Ohm.cm ), pressed • with melamine foil; • Size: 43cm×43cm × 0.6cm • Graphite coat: 40cm × 40cm, • resistivity ~130 kW/ • 95% R134A, 5% iC4H10 • Gas Flow rate: 1 ml/min • Gas leakage rate: 2mm/30m • drop at 30cm water higher • pressure (tested at both with • positive and negative pressure) spacers PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
HV Gas connector Picture of 2 chambers A Real View of 2 chambers Yajun Mao, Ran Han, PKU PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
50 Ohm ground ground The Read-Out Strips Yajun Mao, Ran Han, PKU signal cables PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
Chamber Support/Container Yajun Mao, Ran Han, PKU Al honeycomb panel, both surfaces are coated with 0.5mm Al foil, with 16mm × 16mm Al bars PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
Chamber Support/Container Yajun Mao, Ran Han, PKU
12 Time Distribution of Background (for paddle coincidences) Shielding Clock Forward Forward&BBCLL1 Forward&MUIDS_1D Run04 Config SC2 SC1 ? Top View • Gap from -50 to -10 ns is due to limited size of NTC TDC Window • Late Hits in BBCLL1 events relative to MUIDS_1D is because the MUIDS_1D comes mostly from muons, while BBCLL1 has lots of hadronic backgrounds • Evidence for this in ADC Spectrum (in following slides) • Means Forward&MUIDS_1D selects (probably) muon tracks that go through Muon Arm and hits the forward paddles
Run04 Scintillator RPC Locations Shielding SC2 SC1 RPC2 RPC1 Tunnel View Top View
Time Dist by Channel, Run 171548 Time Distributions Time Dist by Channel, Run 171541 Time Dist by Detector 40 ns RPC1 RPC2 Scint 60 ns RPC1 RPC1 Sc • Run 171541 and 171548, triggered on RPC1|RPC2|SC1|SC2 • Few noisy channels, on edges of RPC1 • Thresholds raised to get above noise, but will lose efficiency • RPC1 has separate copper grounds sheets for ease of R&D, get fringe effects • Much less Incoming Background seen than last year • Worse for RPC1, in IR, and run dependent • Location of RPCs further from beam pipe, better beam control? • RPC and Scintillator Response ~ Same, after accounting for acceptance difference of detectors
RPC Scaler Rates • Scaler rates highly correlated between BBC, MUID, and RPC triggers • RPCor doesn’t see any runs with large amounts of background rates • Total RPC1&RPC2 Triggers = 1.3e6 events • ~105 muon tracks per strip, assuming muons trigger RPC1&RPC2
Muon RPC Bkg Test • Response to real background looks like it will be good enough • But, we would like to see more background! • In principle, RPCs should be 10X less sensitive to neutrons • Different Special Conditions to take RPC data • Polarization Measurement • Vernier Scan • Collimation? • Would like to consult with Angelika to see if measurement of background is interesting to collider physicists. • Formal request will be put in to PC and RC soon… • Getting a prototype also allowed us to gain valuable experience with RPC technology… • The beginnings of our R&D program
Time Resolution Ahn et al, Journal of the Korean Physical Society, Vol 41, No 5, 2002, p 667-673 Sc1-Sc2 Sc1-RPC2 • We should be able to get time resolution by looking at Scintillator and RPC coincidences • Getting ~1-2 ns resolution • Have to fit 2 gaussians in delta-t
Efficiency Sc1 RPC Sc2 • CMS gets ~99% efficiency, compared to 90% from Cosmic Ray Studies with RPC Prototype
Position Resolution • From RPC1&&RPC2 triggers, we should be able to get some muon tracks and determine position resolution (and also efficiency and time resolution) • Good Statistics (~100000/strip)
Future Tasks • Decision on NSF MRI Proposal expected in June • We can press forward with planning until we find out whether we get the money or not • Many Detector R&D Tasks • Effects of different gas combinations, humidity, etc… • Reducing Streamer Rate, reducing noise • Getting position resolutions to the ~ 0.5 centimeter level • Double check timing resolution • Improving efficiency (currently ~ 90% with TOF.W gas) • Checking aging effects • Checking rate effects (beam test?) • Designing and Testing Readout Board and FEMs and Trigger • Colorado has already started to feel out what is necessary for this • Want to organize the next wave of R&D • One RPC to Illinois, one to Colorado at the end of the run. • Illinois and Colorado to study detector issues, • Design and build next generation of the prototype (at PKU) • Full size, resolve current issues, use final materials • Electronics: Colorado, Nevis, Riverside, IA State • ACU has students for summer – trigger simulation (with X. Wei) • GA State has material for another RPC prototype (italian bakelite)
Possible Way to READOUT RPC (from Chi) FPGA RPC Cathode CMS PreAmp ASIC TDC ~(5-10ns or Gated ) L1 Data Buffer DCM Timing Cut Large Pad Trigger: Road L1 Trigger (IA State) f Slice trigger UCR/Colorado/Nevis
Summary • The W-boson measurement is extremely nice and important • By far the cleanest measurement of sea quark contribution to spin • Japanese originally joined PHENIX partly to be able to do this measurement • The W Boson Trigger has gone through a long twisted path • Cerenkov Detector, Hodoscopes, Wire Pad Chambers • Have finally settled on RPC and MuTr FEE Upgrade • Progress is being made at Kyoto on the MuTr FEE Upgrade, in parallel with RPC • NSF-MRI submitted for RPC upgrade • Decision expected this month • If NSF funds a RHIC upgrade, it’s between HBD, RPC, and STAR FMS • Final Design not yet Complete for RPC • This is the time to let us know of any input you might have for the design • Improvements in Pattern Recognition • More Sophisticated Triggering • Upsilon in Au+Au? • R&D Progressing Nicely
From Yong Ban Beam test results of Chinese RPC prototype Conclusion: • The Chinese RPC prototype has good mechanical strength,gas-tightness and HV performances; • The efficiency and time resolution are satisfactory; • The efficiency at very high irradiation is limited due to the high resistivity of the bakelite. The PKU-RPC group accumulated experience and technical know-how of RPC.
Background Study in Run04 p+p Using Paddles * * Commissioned by Xie Wei and Hiro Heijima Side View, South Arm Beam View 62ns Delay NTC FEM fan in/fan out MuID Hole 10 cm 33” Beam Pipe 2 1 Bkg Scint. (9”x12”) 23.5” 31 ns Paddle Locations
Scaled RPC Trigger Counts Total Scaled Counts so far: bbc 1.0111e+09 muid 9.65415e+07 rpcand 1.31369e+06 rpcor 432802
MuTr LL1 trigger (Funding in Japan) PHENIX forward upgrade µ RPC LL1 trigger (NSF proposal) Achieved enough trigger rejection • increase of pion rejection via isolation cut • possible background rejection via reconstructing W transverse mass. • possible improve of momentum resolution with well defined determined vertex.
Simulation Efforts Nosecone calorimeter trigger: Kelly Corriea: Topology based trigger Cerenkov trigger: Jennifer Hom: cerenkov detector + uIDLL1 Lookup table Trigger: Hal Haggard: scintillator hodoscope solutions Greg Ver Steeg: hodoscope solution*muID Tracking trigger: Kazuya Aoki and Wei Xie: Various tracking solution matching muID roads, studies from data Beam Related Background: Vasily Dzhordzhadze: Mars based beam background simulations (ongoing) (details see: http://www.phenix.bnl.gov/WWW/trigger/muonupgrade) Matthias Grosse Perdekamp, RBRC and UIUC