Jim Thomas - LBL 1
News about RHIC
with comments about PHOBOS, BRAHMS and the Upgrade Plans for STAR and PHENIX
Jim ThomasLawrence Berkeley National Laboratory
SQM ‘06 @ UCLAMarch 31st, 2006
Jim Thomas - LBL 2
BRAHMS
PHOBOS
PHENIX
News from RHIC
RHIC can run at 4.6 GeV – see GSFS
Proposal to retire the Tandem accelerators as the HI injector to RHIC
An EBIS source will take their place
All ions will be possible including U and polarized 3He
Cost of operation will decrease
Operational in 2010
hSTARSTARSTAR
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Luminosity Upgrade with Electron Cooling
Gold collisions (100 GeV/n x 100 GeV/n): w/o e-cooling with e-cooling
Ave. store luminosity [1026 cm-2 s-1] 8 70
Pol. Proton Collision (250 GeV x 250 GeV):
Ave. store luminosity [1032 cm-2 s-1] 1.5 5.0
LinacRf Gun
Buncher Cavity
Cooling Solenoid (26 m, 2-5 T)
Debuncher Cavity
e-Beam Dump
Gold beam
Electron cooling reduces the inter-beam Coulomb scattering and reduces the size of the beam at the IP
Luminosity leveling through continuously adjusted cooling
Store length limited to 4 hours by “burn-off”
First collider accelerator to be limited by beam losses due to interactions that are the subject of study by the experiments
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Two “Small” Detectors at RHIC
BRAHMS2 Spectrometers - fixed target geometryMagnets, Tracking Chambers, TOF, RICH
Inclusive particle production over a large rapidity and pt range
PHOBOS“Table-top” 2 Arm Spectrometer Magnet,
Si -Strips, Si Multiplicity Rings, TOF
Low pt charged hadronsMultiplicity in 4 & Particle Correlations
Ring Counters
Paddle Trigger Counter
Spectrometer
TOF
Octagon+Vertex
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News from PHOBOS and BRAHMS
• PHOBOS has completed its data taking mission– Currently being de-commissioned
– Analysis of data on tape is still on-going; such as flow observables from the Cu-Cu run
• BRAHMS’ data taking mission is nearly complete– Request one brief run with polarized protons at 62 GeV
– Analysis of data on tape is still on-going
Congratulations to the “small” experiments for beautiful
physics measurements over a large rapidity interval.
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STAR Solenoidal field
Large Solid Angle TrackingTPC’s, Si-Vertex Tracking
RICH, EM Cal, TOF
Measurements of Hadronic observables using a large acceptance spectrometer
PHENIXAxial Field
High Resolution & Rates2 Central Arms, 2 Forward Arms TEC, RICH, EM Cal, Si, TOF, -ID
Leptons, Photons, and Hadrons in selected solid angles (especially muons)
News from the “Large” Detectors at RHIC
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Detector Upgrades
• Each detector discovers a different part of the Elephant’s story
• The detector upgrades are designed to complete the coverage of the physics program
– and open new vistas
– the charm and beauty sector … dE/dx, flow, coalescence, NCQ scaling
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• Full Barrel MRPC TOF
• DAQ Upgrade (order of magnitude increase in rate)
• Tracking upgrade:
• High precision Heavy Flavor Tracker near the vertex
• Inner tracker
• End cap tracker for W sign determination
• Forward Meson Spectrometer
STAR Upgrades
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The TOF Upgrade
• Multiplate RPC technology
• Beautiful electron ID
• 85 ps timing resolution after slewing corrections
• Each tray has 72 channels
• 2 full tray this year, with new electronics
• Proposal funded by the DOE
• Construction and install in 2006, 2007, and 2008
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One “tray” (2/60 azimuth, 0<<1)
pK
e
• Doubles the pT range for PID
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TPC FEE and DAQ Upgrade – DAQ 1000
• Faster, smaller, better … ( 10x )
• Current TPC FEE and DAQ limited to 100 Hz
• Replace TPC FEE with next generation CERN based chips … 1 kHz readout
• Make the FEE smaller to provide space for a forward tracking upgrade
• Further improvements by only archiving “associated” clusters – build on L3 algorithms … 5 kHz !
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• Four steps to an order of magnitude increase in data acquisition rates
• TPC FEE (BNL&LBL)
• TPC RDO (BNL)
• DAQ Transmitter (CERN)
• DAQ Receiver (CERN)
Dual CERN D-RORC with fibers on the board
Mezzanine DDL
Single D-RORC with 1 fiber mezzanine
ALICE FEE & DAQ
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• A new detector– 30 m silicon pixels
to yield 10 m space point resolution
– 100 M pixels
• Direct Topological reconstruction of Charm
– Detect charm decays with small c, including D0 K
• New physics– Charm collectivity and
flow to test thermalization at RHIC
– Charm Energy Loss to test pQCD in a hot and dense medium at RHIC
• Desirable to have it in time for the next long Au-Au run
The Heavy Flavor Tracker
The HFT: 2 layers of Si at mid rapidity
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Surround the vertex with Si
A thin detector using 50 m Si to finesse the limitations imposed by MCS
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Inner & Forward Tracking Upgrades
• The IST will add high quality space points to tracks in the TPC
– Si at = 0
• The FST and FGT add high quality space points at forward η
– 1 < η < 2
• High Rate tracking for heavy flavor physics and W production
• Add high quality space points to tracks at high rapidity in the TPC by putting a triple-GEM detector in the gap between the TPC electronics and the EEMC3 layers of Si + 2 layers of GEM at forward rapidity
3 layers of Si at mid rapidity
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Forward Meson Spectrometer Upgrade
• Study forward 0 production at RHIC
( 2.4 < < 4.0 )
• Expand the existing FPD array for forward physics
• 2.4 meter square array of PbGl EMCal modules on the West end
• Use finer segmentation in the middle of the array
• Study vector mesons that decay into 0 and/or photons.
• Installation in ‘06
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L.Bland
3.8 cm inner7.6 cm outer
Side View of the East Pole Tip End View of the PbGl Array~ 2.4 m square, ~ 1500 PMTs
The Forward Meson Spectrometer (detail)
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Timeline for STAR Upgrades
Fiscal Year 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
MRPC TOF
FEE & DAQ Upgrade
Heavy Flavor Tracker
Inner Tracker
End Cap Tracker
Forward Meson Spect.
Key R&D Construction First Physics Full System
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PHENIX Upgrade Plan
– An aerogel and time-of-flight system to provide complete /K/p separation for momenta up to 10~GeV/c.
– A hadron-blind detector to detect and track electrons near the vertex
– A vertex detector to detect displaced vertices from the decay of mesons containing charm or bottom quarks.
– A muon trigger upgrade to preserve sensitivity at the highest projected RHIC luminosities.
– A forward calorimeter to provide photon+jet studies over a wide kinematic range.
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PHENIX Central Arm Upgrades
• Enhanced Particle ID– TRD (east) – Aerogel/TOF (west)
• Vertex Spectrometer– flexible magnetic field– VTX: silicon barrel vertex tracker– HBD and/or TPC
High pT phenomena: , K, p separation to 10 GeV/c
charm/beauty: TRD e/ above 5 GeV/c
charm/beauty: displaced vertex
e+e- continuum: Dalitz rejection
HBD/TPC
VTXHBD/TPCVTX
TRD
Aerogel/TOF
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Dalitz Rejection: a Hadron Blind Detector
signal electron
partner positronneeded for rejection
Cherenkov blobs
• Dalitz rejection via opening angle – HBD is a proximity focused Cherenkov
detector with ~ 50 cm radiator length
– Provides minimal signals for charged particle
• HBD concept: – Windowless Cherenkov detector
– CF4 as radiator and detector gas
– CsI reflective photocathode
– Triple GEM with pad readout
Bandwidth 6-11eV, N0 ≈ 940cm-1, Npe ≈40No photon feedbackLow granularity, relatively low gain
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Pixel barrel (50 m x 425 m)Strip barrels (80 m x 3 cm)Endcap (extension) (50 m x 2 mm)
1 - 2% X0 per layerbarrel resolution < 50 m endcap resolution < 150 m
Silicon Vertex Tracker (VTX)VTX barrel ||<1.2
Pixel Detectors at R ~ 2.5 & 5 cm Strip Detectors at R ~ 10 & 14 cm Endcap 1.2<||<2.7
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Forward Upgrade Components• Endcap Vertex Tracker
– silicon pixel detectors
• Nosecone EM Calorimeter– W-silicon (20-50 X/X0)
– shower max
– tail catcherCerenkov
NoseconeCalorimeter
U-Tracker
Muon fromhadron decays
Muon from W
TailCatcher
D-Tracker
Silicon endcap
• Muon trigger– U-tracker (MuTr or new)
– D-tracker (timing with RPC’s)
– Cerenkov
charm/beauty & jets: displaced vertex
-jet,W,c: calorimeter
W and quarkonium: improved -trigger rejection
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Nose-Cone Calorimeter• Replace existing PHENIX “nose-cones”
(hadronic absorbers for muon arms) with Si-W calorimeter (Tungsten with Si readout)
• Major increase in acceptance forphoton+jet studies
• Prototype silicon wafer – 3 different versions of
“stri-pixel” detectors for the preshower and shower max layers
• Extended physics reach q/q polarizations via spin
dependent W-production
– Small x-physics in d-A
– Extended A-A program
– high pT phenomena: 0 and -jet
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2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Aerogel
TOF-W
HBD
VTX-barrel
VTX-endcap
NCC
MuTrigger
DAQ
R&D Phase Construction Phase Ready for Data
PHENIX Upgrades Schedule
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Summary
• The scientific program at RHIC is rich and diverse– Rare probes and high pt phenomena are a rich source of new
discoveries
– Strangeness, Charm, and Beauty are likely to yield even more new discoveries
– We have promising spin program that is making critical and unique measurements
• The scientific program at RHIC will keep getting better– The performance of the accelerator is improving each due to a
carefully planned set of upgrades.
– STAR will explore charm, beauty, and higher pt spectra at ever increasing data acquisition rates.
– PHENIX will add sophisticated PID and tracking near the vertex.
• These upgrades will yield exciting new physics results
The Future is Very Bright
