Detector for GlueX

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Detector for GlueX
Beamline Hall D
GlueX Detector
Software Trigger
Computing Environment
Physics
PRL

• JLab PAC 23
• Jan 20, 2003

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What is needed?

• 9-GeV polarized photon beam
• Coherent bremsstrahlung beam
• Hermetic detector for multi-particle charged and
  neutral final statesCharged
• Solenoid-based detector
• Select events of interest with high sensitivity
• High DAQ rate capability with software trigger
• Analysis environment for successful PWA

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Construction Site
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Status of Civil Design

• Credible optics design
• Layout that provides room for detectors and
  access to equipment
• Beam containment proposal
• Concept for civil design
• GEANT Calculations show that the shielding
  satisfies radiation protection guidelines

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Hall D site layout
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Coherent bremsstrahlung beam
Delivers the necessary polarization, energy and
flux concentrated in the region of interest
P 40
Linear Polarization
Photon beam energy (GeV)
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Hybrid decays
GlueX will be sensitive to a wide variety of
decay modes - the measurements of which will be
compared against theory predictions.
Gluonic excitations transfer angular momentum in
their decays to the internal angular momentum of
quark pairs not to the relative angularmomentum
of daughter meson pairs - this needs testing.
For example, for hybrids
favored
Measure many decay modes!
not-favored
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GlueX detector
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Solenoid ships from Los Alamos
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Unloading at IUCF
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Exploded view of the GlueX detector
CERENKOV
Pb-GLASS DET
TOF
12.00
TARGET
VTX
CDC
FDC
The components are extracted by 4 ft from each
other for maintenance.
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Particle kinematics
g p ? X p ? KK-pp- p
Most forward particle
All particles
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GlueX Detector
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Central tracking
Straw tube chamber
Vertex Counter
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Forward drift chambers
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Charged particle resolution
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Calorimetry
Pb Glass
Barrel
Built by IU for BNL Exp 852
Pb/SciFi detector based on KLOE s/E 4.4 / vE,
threshold 20 MeV st 250 ps
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Particle identification
Time-of-flight, Cerenkov counter, and constraints
for exclusive events
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Hall D Prototype (IHEP Run 2001)
R. Heinz / IU
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PID with Cerenkov and forward TOF
TOF s 100 ps resolution
gp ? KK?pp?p, Eg 9 GeV
n 1.0014
n 1.0024
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Acceptance is high and uniform
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Trigger and DAQ
Start _at_ 107 g/s Open and unbiased trigger Design
for 108 g/s 15 KHz events to tape
Level 1 trigger system With pipeline electronics
Software-based Level 3 System
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Trigger and DAQ
Hadronic rate in detector
Start _at_ 107 g/s Open and unbiased trigger Design
for 108 g/s 15 KHz events to tape
Level 1 trigger system With pipeline electronics
Software-based Level 3 System
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Trigger Rates
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Luminosity limits
GlueX raw rates will be well below
currently running CLAS electron beam experiments
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DAQ architecture
90 VME front-end crates
Gigabit switch 200 KHz
8 event builders
8 100-Mbit switches
200 Level 3 Filter Nodes
4 event recorders
Network connection to silo 15 KHz
4 tape silos
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Fully pipeline system of electronics

• Deadtimeless
• Expandable
• No delay cables

Flash ADCs 13000 channels TDCs 8000
channels
(Non-pipeline Limits photon flux lt 107/s, incurs
deadtime, requires delay cables)
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Data Volume per experiment per year (Raw data -
in units of 109 bytes)
But collaboration sizes!
Ian Bird
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Data Handling and Reduction
CLAS GlueX
Event size 5 KB 5 KB
Data volume 100 TB/year 1000 TB/year
cpu speed 0.4 GHz 6.4 GHz
cpu time per event 100 ms 15 ms
cpu count 150 225
Reduction speed 7 MB/s 75 MB/s
Throughput limit cpu speed cpu speed
Reduction time 0.5 year 0.4 year
Data rate up by 10, computer costs down by gt 5
? GlueX Computing Effort 2 x CLAS
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Computing Model
Tier 2 Centers
Calibration
Tier 1 Center (Jlab)
20 MB/s
Physics Data
0.2 PB/yr
Physics Analysis
70 MB/s
Physics Analysis
100 MB/s
20 MB/s
Tier 2 Simulation Center
Monte Carlo
0.2 PB
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Detector designed for PWA
Double blind studies of 3p final states
Linear Polarization
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Leakage
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Ongoing RD effort

• Solenoid shipped to IUCF for refurbishment
• Tracking testing straw chamber fabricating
  endplate prototype (CMU)
• Vertex - study of fiber characteristics (ODU/FIU)
• Barrel calorimeter beam tests at TRIUMPF
  fabricated first test element of the Pb/SciFi
  matrix (Regina)
• Cerenkov counter magnetic shield studies (RPI)
• Time-of-flight wall results of beam tests at
  IHEP show slt50 ps (IU)
• Computing developing architecture design for
  Hall D computing
• Electronics prototypes of pipeline TDC and
  FLASH ADC (Jlab/IU)
• Trigger Studies of algorithm optimization for
  Level 1(CNU)
• Photon tagger benchmarks of crystal radiators
  using X-rays (Glasgow/UConn)
• Civil beam height optimized electron beam
  optics shortens length of construction new
  radiation calculations completed (Jlab)

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• Benchmarks of Diamond Crystals

High Quality
Poor Quality
Stone 1407 Slice 1 (4mm x 4 mm X-ray
rocking curve)
Stone 1482A Slice 2 (10mmx10mm
X-ray rocking curve)
Richard Jones / Uconn
R.T. Jones, Newport News, Mar 21, 2002
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Straw Tube chamber work
Graduate Students Zeb Krahn and Mike Smith
Built a b-gun using a 10 mCi 106Ru Source
Getting coincidences with both cosmics and bs
ArCO2 90-10 ArEthane 50-50
Carnegie Mellon University
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Building a Prototype Endplate
Build endplates as 8 sections with tounge and
groove.
Checking achievable accuracy
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Barrel calorimeter prototyping
Hybrid pmts can operate in fields up to 2 Tesla
Pb/SciFi prototype
University of Regina
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FLASH ADC Prototype
250 MHz, 8-bit FADC
Paul Smith / IU
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Pipeline TDC
First prototype results high resolution mode
Jlab DAQ and Fast Electronics Groups
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Cassel review of Hall D concluded
The experimental program proposed in the Hall D
Project is well-suited for definitive searches
for exotic states that are required according to
our current understanding of QCD
An RD program is required to ensure that
Working with input from many groups on
electronics, DAQ, computing, civil, RadCon,
engineering, and detector systems.