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