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Trigger Upgrades to the PHENIX Muon Arms
Mickey Chiu
University of Illinois at Urbana-Champaign
for the Forward Upgrade Group
Parity violating single-spin asymmetries at RHIC provide direct access to the quark flavor structure of the proton spin:
Quark Flavor Structure Measurement at RHICPolarised PDF
Asymmetry Analysis Collaboration M. Hirai, S. Kumano and N. Saito, PRD (2004)
forward rapidities
A Wu x
u xLa
a
( )( )
( )
, Xa>>Xb
, Xb>>Xa A Wd x
d xL
b
b
( )( )
( )
RHICBOS predicted Sensitivity at RHIC
•PHENIX
•central arm: |η|<0.35, ∆=electron
•Muon arm: 1.2<|η|<2.4, ∆=2muon
Nuclear Physics B666(2003)31-55
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
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?
Phenix muon arm
BLUE = 600 μmRED = 300 μmBLACK = 150 μm
• 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
Why do We need to Upgrade Muon Trigger
• uIDLL1 rejection factor from simulation at sqrt(500)GeV, i.e. perfect shielding is ~500
• uIDLL1 rejection factor from RUN3 p-p data is ~250 w/o shielding
Wei Xie
Backgrounds to the W Measurement
Charged hadron
through absorber
Major background from the pion punch through and Z0 decay.
Measurement: pT>20GeV/c
Still to Consider:
• Charged hadron rejection through absorber
• ~100
•More rejection from the shower profile on the tube.
•More rejection from isolation cut: ~5
Total rejection: ~103
1. Cosmic Background2. Punch Through and Decays
• low p hadrons look like high p
Trigger Cut
-
+
Sagitta<=1 strip
Sagitta<=2 strips
Sagitta<=3 strips
Rej 23700 10900 7180
Result from Kazuya Aoki
A birds eye view
Trigger Option I: MuTr FEE Upgrade Solution
eff
icie
ncy
Sagitta<=1 strip
Sagitta<=2 strips
Sagitta<=3 strips
•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
MuTr FEE – proposed modification
MuTr Cathode
AMUADC
DCM
GL1BBCLL1
MuIDLL1
CPA
(3 mV/fC)
~1usec
FPGA(MuTrLL1)
PADiscri
0.8mV/fc ~80nsec
Hit pattern
Analog outshaper
MA
Modified ATLAS ASD
additional gain x 8
ASD Chip Test Board (ver 1) Signal from Chamber
Analog Output Digital Output (LVDS)
8Chips on board
4Channels / Chip
Analog out Gain 0.8mV/fC
Integration Time
80nsec
LVDS Digital out
Signal
200nsec/divAnalog out 5mV/div
Digital out LVDS
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
sub
main
sub
main
L
L=
V
V
Get Digital Signal
• We could get the Digital Output• Without Distortion of Main Line Signal
ASD
Analog Output
(Signal of Sub Line)
ASD
Digital Output
1V/div
Main Line Signal
5mV/div
Time Scale 1usec/div
Effect of Noise
• Sub Line Signal is easily affected by Main Line Noise
Perfect!!
Noise of Main Line
Noise of Main Line
Causes Fake Trigger
Test stand with VDCs in
KyotoVDC
Muon Tracker
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 road ID ()=angle I – angle II: momentum cut
Trigger Option II: pad chamber solution
deg <0.7 <1.0 <2.0
rejection 41458 22111 11845
deg <0.7 <1.0 <2.0
rejection 9851 6503 3258
deg <0.7 <1.0 <2.0
rejection 31093 22011 9128
1 million sqrt(s)=500GeV minimum-bias, full PISA simulation
Segmentation
distance between two closet hits as a function of r at 95% probability
North South
Chun Zhang
•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
$2 Million NSF MRI Proposal
Development of a Fast Muon Trigger to Study the Quark-Gluon Structure of the Proton
University of ColoradoUniversity of ColoradoFrank Ellinghaus, Ed Kinney, Jamie Nagle, Joseph Seele, Matt Wysocki
University of California at RiversideUniversity of California at RiversideKen Barish, Stefan Bathe, Tim Hester, Astrid Morreale, Richard Seto, Alexander Solin
University of Illinois at Urbana ChampaignUniversity of Illinois at Urbana ChampaignMickey Chiu, Matthias Grosse Perdekamp, Hiro Hiejima, Naomi Makins,
Jen-Chieh Peng, Ralf Seidl, Chris Prokop, John Koster, Aaron Veicht
Iowa State UniversityIowa State UniversityJohn Lajoie, John Hill, Gary Sleege
Kyoto UniversityKyoto UniversityKazuya Aoki, Ken-ichi Imai, Naohito Saito, Kohei Shoji
Columbia UniversityColumbia UniversityCheng Yi Chi, William Zajc
RBRCRBRCGerry Bunce, Wei Xie
Abilene Christian UniversityAbilene Christian UniversityRusty Towell, Larry Isenhower
Peking UniversityPeking UniversityYajun Mao, Ran Han, Hongxue Ye, Hongtao Liu
Current collaborators on W-project
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 12 cm
2-3kHz/cm2 in avalanche mode!
Single Gap RPCs (CMS style design)
Pick-up cathodes and FEE
Avalanche:The electric field is such that the electron energy is larger than the ionising potential
Basics of Resistive Plate Chamber: working modeBasics of Resistive Plate Chamber: working mode
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.
From Yong Ban
Cost + Schedule
2005 First Prototype Test in Run05 Beam2006 Full scale prototype plus electronicsWinter 2006 Test of Full scale prototype in Run072007-2008 Production of all planes and electronicsSummer 2007 Installation in South Muon Arm RPC TriggerWinter 2007 Commissioning of South RPC Trigger in
Run08Summer 2008 Installation of North Muon Arm RPC TriggerWinter 2008 Commissioning of North RPC Trigger in
Run09Run09 High Luminosity s = 500 GeV p+p Run
PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
The Structure of PrototypeYajun Mao, Ran Han, PKU
PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
Top View of A Single Chamber
• Material: 2mm bakelite
( 2~3 × 1011 Ohm.cm ), pressed
with melamine foil;
• Size: 43cm×43cm × 0.6cm
• Graphite coat: 40cm × 40cm,
resistivity ~130 k/• 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
Yajun Mao, Ran Han, PKU
PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
A Real View of 2 chambers
Picture of 2 chambers
Gas connector
HV
Yajun Mao, Ran Han, PKU
PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
The Read-Out Strips
ground
50 Ohm
ground
signal cables
Yajun Mao, Ran Han, PKU
PHENIX Forwarding Upgrade Meeting Nov. 8, 2004
Chamber Support/Container
Al honeycomb panel, both surfaces are coated with 0.5mm Al foil, with 16mm × 16mm Al bars
Yajun Mao, Ran Han, PKU
Chamber Support/ContainerYajun Mao, Ran Han, PKU
Time Distribution of Background
ClockForward
Forward&BBCLL1Forward&MUIDS_1D
•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
?
(for paddle coincidences)
SC1SC2
Shielding
Top View
Run04 Config
12
RPC Locations
RPC1
RPC2SC1SC2
Shielding
Top View
Tunnel ViewRun04 Scintillator
Time Distributions
RPC1RPC2Scint
Time Dist by Channel, Run 171541Time Dist by Detector
•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
Time Dist by Channel, Run 171548
RPC1 RPC1 Sc
40 ns
60 ns
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 ResolutionAhn et al, Journal of the Korean Physical Society, Vol 41, No 5, 2002, p 667-673
•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
Sc1-Sc2
Sc1-RPC2
Efficiency
•CMS gets ~99% efficiency, compared to 90% from Cosmic Ray Studies with RPC Prototype
RPC
Sc1
Sc2
2&1
2&1&
ScSc
ScScRPC
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)
CMSPreAmp
ASIC
TDC~(5-10ns or
Gated )
Timing Cut
Large Pad Trigger: Road
Slice trigger
L1 Data Buffer
DCM
L1 Trigger
Possible Way to READOUT RPC (from Chi)
FPGA
RPCCathode
UCR/Colorado/Nevis
(IA State)
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
Backup Slides
Inclusive charge hadron spectrum (PYTHIA and UA1)
Beam test results of Chinese RPC Beam test results of Chinese RPC prototypeprototype
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.
From Yong Ban
Background Study in Run04 p+p Using Paddles *
1
BkgScint.
(9”x12”)
33”
23.5”
MuID Hole
BeamPipe 2
Beam View Side View, South Arm
fan in/fan out
62ns Delay NTCFEM
10 cm
31 ns
* Commissioned by Xie Wei and Hiro Heijima
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
PHENIX forward upgrade
deg <0.7 <1.0 <2.0
rejection 36000 19980 10090
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.
RPC LL1 trigger (NSF proposal)
MuTr LL1 trigger (Funding in Japan)
µ
Simulation Efforts
Matthias Grosse Perdekamp, RBRC and UIUC
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)
R&D and test data
Matthias Grosse Perdekamp, RBRC and UIUC
Evaluation of muID LL1 Wei Xie, Ken Barish: using run 03 data (UCR)
Background Hiroki Sato: run 02 (Kyoto)
Ken Read, Vasily Dzhordzahdze, Vince Cianciolo: run 03, run04 (UT, ORNL) Wei Xie, Hiro Hiejima, MGP (RBRC, UIUC)
Cherenkov Kazuya Aoki, Naohito Saito, Atsushi Taketani: run 03 (Kyoto, RIKEN)
Nosecone Mikhail Merkin, Edward Kistenev, Richard Seto, Gianluigi Sampa (MSU, BNL, UCR, INFN Trieste)
MuTr Kazuya Aoki, Hiroki Sato, Naohito Saito, Doug Fields (Kyoto, UNM)
RLT/RPC Hiro Hiejima, Alex Linden Levy, Cody McCain, Jen-Chieh Peng, Joshua Rubin, Wei Xie, Matthias Grosse Perdekamp (UIUC, RBRC)
R1 Real Estate
New PHENIX Experiment Specific Shielding –
(final configuration in progress)Typical Background
iron 4’ thick, 10.5' tallPlan View
Elevation View
Blue beam Yellow beam
MuIDMuID
Beam Background simulationsVasily Dzhordzhadze
-+p
+ - e+e-
n
Particles reached MuID
Gap 5 absorber
10K 100 GeV protonsincident on Q03Integrated overallEnergies