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Silicon Vertex Tracker (VTX)Silicon Vertex Tracker (VTX)forfor
PHENIX Experiment at RHICPHENIX Experiment at RHIC
Y. Akiba (RIKEN)for
PHENIX collaboration
Detector Advisory Committee Meeting November 22, 2003
VTX proposalVTX proposal
65 authors from 14 institutes 4 institutes outside of present
PHENIX
Main part (VTX barrel)About 100 pages52 figures8 tables
Appendix (EndCap extension)
about 20 pages
16 figures
Pixel barrels (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
1.2<||<2.4||<1.2
Silicon Vertex Tracker in PHENIXSilicon Vertex Tracker in PHENIX
Physics Beyond Reach of Current PHENIX Physics Beyond Reach of Current PHENIX
Detailed study of the hot and dense matter formed in Au+Au collision Precise measurement of charm production
Charm enhancement in pre-thermal stageReference for J/ measurement
Beauty measurement in Au+Au collisions Flavor dependence of QCD energy loss in hot matter Thermal di-lepton pair (charm background) High pT charged particle (pT > 10 GeV/c)
G measurement in broad x range in polarized p+p collision Charm/beauty production +jet measurement
Gluon shadowing in broad x range by heavy quark production
Measurements complement and enhance the present physics program• fully exploit existing rare event capabilities of PHENIX
Provide key measurements so far inaccessible at PHENIX:
Open Charm and BeautyOpen Charm and Beauty Physics interest in charm and beauty in Heavy Ion Collisions
Charm enhancement in pre-thermal stage Do heavy quarks lose energy in quark matter? critical base line for J/ and Y production & dilepton continuum
Spin Physics with charm/beauty Gluon polarization in wide
PHENIX measured charm via inclusive electron (PRL88 (2002) 192303) Indirect measurement can not distinguish charm and beauty for pT > 2.5 GeV/c
beauty
charm
Charm and beauty separation aim of future PHENIX program
Physics from precise charm measurementsPhysics from precise charm measurements
Is there pre-thermal charm production?
Precise charm measurementis required to detect small enhancement
Does charm flow? Does charm suffer energy loss?
Charm measurement in pT>3 GeV/c is required to see energy loss effect
Thermal dileptons from the QGP
Di-leptons from charm decaymust be identified and subtracted to detect the thermal di-leptons from the QGP in 1-3 GeV region
These measurements are not possible or very limited without the VTX
D
Detection of decay vertexwill allow a clean identifications of charm and bottom decays
m cGeV m
D0 1865 125 D± 1869 317
B0 5279 464 B± 5279 496
Need secondary vertex resolution < 50 m
Beauty and high pT charm will require high luminosity
Direct Observation of Open Charm and BeautyDirect Observation of Open Charm and Beauty
Detection options:• Beauty and low pT charm through displaced e and/or • Beauty via displaced J/• High pT charm through D K
Au
e
AuD
X
J/
B
X
K
ee
Charm measurements with the VTXCharm measurements with the VTX
Precision DCA (Distance of Closest Approach) measurement by the VTX strongly suppress background from Dalitz and the conversion
More than factor 10 improvements of S/B.
In low pT region, electron spectrum after the DCA cuts is dominated by charm decay
Robust charm measurement at low pT
ce / be separation from the difference of decay length
Extends ce measurement beyonds pT>2.5 GeV/c
Measurement of energy loss of charm
c e by barrel+central arm
Direct measurement of Direct measurement of DDKK
Simulation of DK(pT>2 GeV/c) with VTX
1 % radiation length per layer
After a DCAcuts, 7 significance is achieved for central Au+Au collision
DCA of primary tracks DCA of DK
Signal significance (S/B1/2) of DK
DCA cuts
7
DCA(cm) DCA(cm)
beauty measurement with VTXbeauty measurement with VTX
In high pT (pT>3 GeV/c), the electron spectrum is dominated by beauty decay
Clear separation of b from c using the difference of decay length
b measurement in 1<pT<6 GeV/c, covering >50% of be yield
Accurate beauty measurement is not possible without the VTX
b e by VTX + central arm
Spin Physics with VTXSpin Physics with VTX
Measurement of Gluon polarization by Heavy flavor production c, b e, + displaced vertex B displaced J/ DKat high pt
VTX measurement of displaced vertex Improved S/B higher sensitivity to G(x) Much broader x coverage
VTX significantly increases the x coverage of G(x) measurement
Gamma+JetsGamma+Jets
In p+p or p+A collisions, the VTX works as a stand alone, large solid angle tracker
The VTX is used to detect the recoil jets in the direct photon events.
PYTHIA simulation with the VTX acceptance
RMS resolution of initial parton x is ~20% with the VTX
Without the VTX With the VTX
RMS resolution of x1
Measurement of gluon shadowing with VTXMeasurement of gluon shadowing with VTX
Heavy-flavor measurement in p+A Single lepton and J/ with displaced vertex
Heavy-flavor production via g+g q+q Extracting gluon structure function nuclei, shadowing
vertex detector provides broader range in x into predicted shadowing region (x ~ 10-2 )
coverage w.the VTX
Expected Signal yield in RUN8Expected Signal yield in RUN8
Many of these measurements are not possible or very marginal without the VTX
NO
NO
NO
NO
NO
NO
marginal
limited
limited
limited
limited
limited
Barrel VTX detectorBarrel VTX detector
Summary of the parameters of the VTX
Barrel detector(GEANT model)
Pixel detectorPixel detector
Use pixel detector technology developed for ALICE and NA60
RIKEN/ALICE collaboration Pixel size: 50 x 450 ALICE1LHCb read-out chip
32 x 256 ch / chip Configuration of PHENIX
VTX pixel layer 1 sensor chip (4x128x32
pixels) is read-out by 4 ALICE chips
2 sensor chip / half ladder 2 half ladder / 1 ladder 20 ladders/ pixel layer
1.2 % radiation length R=2.5 cm
Readout Bus
Detector
readout chip
Support/cooling
Half ladder
Pixel detector
Pixel Readout (ALICE PILOT module)Pixel Readout (ALICE PILOT module)
Use a variant of ALICE PILOT module to read-out the pixel data and the data by optical fiber link
10 MHz read-out, 25.6 usec per chip, using the ALICE chip set Some modification may be needed for digital PILOT (R&D)
Analog PILOT(control, etc)
digital PILOT(read pixel data)
Optical link driver chip
(GOL)
Optical package
data
clock & control
Read out BusFrom pixel
Optical I/OPILOT module
Pixel at Work (NA60)Pixel at Work (NA60)
The Pixel detector is used for target spectrometer of NA60 experiment at SPS
A part of RIKEN and StonyBrook group participates in NA60 to gain experience of using the pixel detector in a real experiment
The pixel detector worked very well in the recent In+In run of NA60
The success of NA60 run demonstrates the capabilities of the pixel technology:
High efficiency Low noise hit rate It worked in extremely high
radiation environment (>M rad during the run)
beam test of pixel detector (ALICE)beam test of pixel detector (ALICE)
Beam time; Oct-22 – Nov-08 Indium ion beam on to Sn target RIKEN group participate in the
ALICE beam test 5 single chip + 1 ladder in beam
test Ladder is read by “almost real”
PILOT MCM and “almost real” pixel read-out bus for ALICE
Success to read data with full readout chain Pixel ladder + Pixel Bus + MCM ( Digital Pilot chip + GOL )
Beam test set up for ALICE pixel
Barrel strips detectorBarrel strips detector
Outer 3 layers use Si strip detector technology
Use a novel, single sided, two dimensional read-out sensor developed by Z. Li of BNL Inst. Division
80 x 3 cm strip X/U stereo read-out 384 x 2 x 2 per sensor chip (64.6 mm
x 30.7 mm) V1 prototype was tested by RIKEN
group V2 prototype 400 and 300 thick
is being made. (Will be delivered in this year)
4 sensor chips / ladder R2 (R=6cm) 10 ladders R3 (R=8cm) 14 ladders R3 (R=10cm) 18 ladders
Sensor structure (ver1)
One strip sensor chip
64.6mm
30.7mm
Strips detector read-outStrips detector read-out
Use SVX4 chip developed by FNAL/LBNL for the Tevatron SVTX upgrade
128 ch/chip 50 pitch read-out 42-deep pipe line On-board 0-suppression
Designed for AC coupled device. (Z.Li sensors DC-coupled)
Frequent storage-cap reset AC/DC conversion by RC
chip in the pitch adaptor
Recently, Tevatron SVTX upgrade project was cancelled. Three are already sufficient SVX4s produced. We are in negotiation with FNAL to purchase these chips.
SVX4 chip
One
sen
sor
Sensor bond-pad rows
ASICX-View
A-C
ASICX-View
D-F
ASICU-View
A-C
ASICU-View
D-F
One
RO
CSVX4
U-View(A)
SVX4U-View
(B)
SVX4U-View
(C)
SVX4U-View
(D)
SVX4U-View
(E)
SVX4U-View
(F)
SVX4X-View
(A)
SVX4X-View
(B)
SVX4X-View
(C)
SVX4X-View
(D)
SVX4X-View
(E)
SVX4X-View
(F)
X-V
iew
Rea
dout
U-V
iew
Rea
dout
One
sen
sor
Sensor bond-pad rows
ASICX-View
A-C
ASICX-View
D-F
ASICU-View
A-C
ASICU-View
D-F
One
RO
CSVX4
U-View(A)
SVX4U-View
(B)
SVX4U-View
(C)
SVX4U-View
(D)
SVX4U-View
(E)
SVX4U-View
(F)
SVX4X-View
(A)
SVX4X-View
(B)
SVX4X-View
(C)
SVX4X-View
(D)
SVX4X-View
(E)
SVX4X-View
(F)
X-V
iew
Rea
dout
U-V
iew
Rea
dout
Cooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensor
SVX4sROCsSensor
a)
b) c)O
ne s
enso
r
Sensor bond-pad rows
ASICX-View
A-C
ASICX-View
D-F
ASICU-View
A-C
ASICU-View
D-F
One
RO
CSVX4
U-View(A)
SVX4U-View
(B)
SVX4U-View
(C)
SVX4U-View
(D)
SVX4U-View
(E)
SVX4U-View
(F)
SVX4X-View
(A)
SVX4X-View
(B)
SVX4X-View
(C)
SVX4X-View
(D)
SVX4X-View
(E)
SVX4X-View
(F)
X-V
iew
Rea
dout
U-V
iew
Rea
dout
One
sen
sor
Sensor bond-pad rows
ASICX-View
A-C
ASICX-View
D-F
ASICU-View
A-C
ASICU-View
D-F
One
RO
CSVX4
U-View(A)
SVX4U-View
(B)
SVX4U-View
(C)
SVX4U-View
(D)
SVX4U-View
(E)
SVX4U-View
(F)
SVX4X-View
(A)
SVX4X-View
(B)
SVX4X-View
(C)
SVX4X-View
(D)
SVX4X-View
(E)
SVX4X-View
(F)
X-V
iew
Rea
dout
U-V
iew
Rea
dout
Cooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensorCooling / Support Structure
SVX4sROCsSensor
SVX4sROCsSensor
a)
b) c)
Read-out scheme:2 Read-Out Cards (ROCs) mounted on each sensor. Each ROC has 6 SVX4s
Silicon Vertex Tracker R&DSilicon Vertex Tracker R&D
Beam test at KEK by RIKEN/Kyoto
=52 =35 =45 =35 =49
Source test at RIKEN
MechanicMechanical structureal structure and cooling and cooling
• Different structures were considered Choose single-barrel shape. • Material: GFRP• Cooling• Radiation length: <1% per layer
Design of support structure by HYTEC Cooling of the barrel
FEM analysis
Gravity deformation
Distortion from thermal strains
Remaining R&DRemaining R&D
Pixel Detector Pixel readout bus
Design and prototyping by Sep 2004 PILOT module
Modification of digital pilot chip to meet PHENIX specification
Technology choice (modified ASIC or FPGA) by April 2004 Pixel FEM
First prototype by Sep 2004 Strip detector
Full chain test of SVX4 read-out of the strip sensorUse the second proto-type of the strip sensorTest completed by April 2004
the SVX4 read-out cardThe first prototype cycle completed by July 2004
Integration Specifications of mechanical design Mechanical design study
R&D support from RIKEN and DOE. Request DOE R&D fund of ~$280K
BudgetBudget
Contribution from RIKEN $3M for 2004-2006+ man-power, etc (~ $1M)
Total DOE costs:$5.6M in FY05-07Direct: $3.7MOverhead: $0.3MContingency $1.6M (~40%)
Profile for the DOE costs
Q1 Q2 Q3 Q4 FY2005
Q1 Q2 Q3 Q4 FY2006
Q1 Q2 Q3 Q4 FY2007
$0.5M/Q
scheduleschedule
Start construction in FY05 Construct in FY05-07 Part of the VTX will be built and installed for RUN7 Complete detector installed in RUN8
2003 2004 2005 2006 2007
SummarySummary Physics with the VTX detector
Au+AuPrecise measurement of charm productionEnergy loss of charm at high ptBeauty production
Polarized p+pG(x) measurement in wide x range (polarized proton)
p+A (d+A)Gluon shadowing in wide x range
Proposed Silicon vertex detector 1 pixel layer 3 strips layers R&D in past 2 years
Cost and Schedule Ready for start of construction in FY05 $3M contribution from RIKEN $5.6M of total cost for the DOE in FY05-07 Install the full detector in RUN8 (FY08)
backupsbackups
Silicon strip detector R&DSilicon strip detector R&D
Prototype v.2 p+ line: 7m 5m gap: 6m 3m turn: 3 turns 5 turns delivery: December
Test readout board SVX4 readout chip by
FNAL/Berkeley collaboration I/F board to PHENIX DAQ by
ORNL PHENIX DAQ emulation on
PC
CDF hybrid
SV
X4
SV
X4
SV
X4
SV
X4
CDF hybrid I/F board
FPGA
I/O FIFO
cable
USB
PCLabViewGUI
v.2 prototype sensor
pitch adapter
Silicon strip detector R&DSilicon strip detector R&D
Laser test bench at BNL instrumentation to study basic properties of the sensor to find optimum operation parameters