1Jim Thomas - LBL
The STAR Heavy Flavor TrackerAn Update and Progress Report
Jim Thomas
Lawrence Berkeley National Laboratory
March 6th, 2012
2Jim Thomas - LBL
The Light Quark Program at RHIC is Compelling
Lattice results
Its hot
Its dense
and it flowsat the partonic scale
and , too!
Spectra
Vn
Jets & Rcp
The evidence for a low viscosity, strongly interacting QGP is overwhelming, especially after QM 2011 (v3 , vn wow …!!)
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Where do we go from here?
• The Beam Energy Scan has been and will continue to be extraordinarily productive
– Alexander Schmah “Elliptic Flow of Identified Particles in Au+Au Reactions at √sNN = 7.7-62.4 GeV” … a tour de force
• Heavy Flavor– Elliptic flow for Charm is the smoking gun for thermalization at RHIC
– Heavy Flavor energy loss … still a bit mysterious
– Clear separation of Charm and Beauty by the topological reconstruction of events will enable a new range of precision
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HFT Charm
Where does all the Charm go?
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Opening the Heavy Flavor Sector
• When RHIC turned on … Strange quarks were “heavy and exotic”– We built a Si vertex tracker to locate strange mesons and baryons
– This turned out to be too easy to do with the TPC, alone
– Kaons, Lambdas, Omegas, Phi and even the Cascade
– Cross sections, Flow, Raa and more
• Now we want to re-define “heavy and exotic” and go after the Charm quark– Some success already with non-photonic electrons (leptonic and semi-leptonic
decays)
– Topological reconstruction of open Charm is better. Requires a new high resolution Si detector.
• Of course, at the LHC the definition of “heavy and exotic” is quite different. The yield of charmed mesons is greatly enhanced and so they are not exotic. B decays may be “rare and exotic” for ALICE … but maybe not. s can do magical things ….
– Note that some success with Upsilon’s at RHIC. Upsilon suppression reported by STAR at QM 2011 using non-photonic electrons.
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The HFT – Signature Physics Measurements
• hello
DOE milestone for 2016: “Measure production rates, high pT spectra, and correlations in heavy-ion collisions at √sNN = 200 GeV for identified hadrons with heavy flavor valence quarks to constrain the mechanism for parton energy loss in the QGP.”
Charmed Hadron v2
using 200 GeV Au+Au minimum bias collisions (500M events)
Charm-quark flow
Thermalization
of light-quarks
Charm-quark does
not flow
Drag coefficients
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• Non-photonic electrons decayed
from charm and beauty hadrons
• At pT ≥ 6 GeV/c,
RAA(n.p.e.) ~ RAA(h±)
• A surprising result
The HFT – Heavy Quark Energy Loss
• Here is what we can do with the HFT using topological ID of open charm
RC
P
STAR PRL 98 (2007) 192301 and Erratum
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The HFT: The Challenge
The STAR HFT has the capability to reconstruct the displaced vertex of
D0 K(B.R 3.8%, c = 123 m) Λc Kp (B. R. 5.0%, c = 59.9 m)and more …
• Primary Challenges
– Neutral particle decay
– Proper lifetime, c, 123 m
– Find a common vertex away from the primary vertex
– Identify daughters, measure pT , and reconstruct the invariant mass
Topological Reconstruction of Open Charm
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The Heavy Flavor Tracker: Location inside the TPC
• hello
PXL IST SSD
TPC
4 m
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The HFT – The configuration
SSDIST
Pixel Detector
10
20
30
-30
-10
-20
0
Cen
timet
ers
Beampipe
• The HFT puts 4 layers of Silicon around the vertex
• Provides 8 m space point resolution @ 2.5 cm
• 30 m vertex resolution @ 1 GeV, 10 m @ 5 GeV
• Works at high rate (~ 800 Hz – 1K)
• Does topological reconstruction of open charm
• Will be ready for the 2014 run
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Tracking: Getting a Boost from the TPC
• The TPC provides good but not excellent resolution at the vertex and at other intermediate radii
~ 1 mm
• The TPC provides an excellent angular constraint on the path of a predicted track segment
– This is very powerful.
– It gives a parallel beam with the addition of MCS from the IFC
• The best thing we can do is to put a pin-hole in front of the parallel beam track from the TPC
– This is the goal for the Si trackers: SSD, IST, and PXL
• The SSD and IST do not need extreme resolution. Instead, the goal is to maintain the parallel beam and not let it spread out
– MCS limited
– The PXL does the rest of the work
TPC
MCS Cone
VTX
The Gift of the TPC
OFC
IFC
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The performance of the TPC acting alone
• The performance of the TPC acting alone depends on the integration time of the PXL chip
P(good association) = 1 / (1+S) where S = 2 x y
Integration Time (sec)
Sin
gle
Laye
r E
ffici
ency
The purpose of intermediate tracking layers is to make 55% go up to ~100%
Note that the hard work gets done at PXL layer 2. This is a surprise.
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The performance of the TPC + SSD + IST
• The performance of the TPC + SSD or TPC + IST acting together depends on the integration time of the PXL chip … but overall the performance is very good
P(good association) = 1 / (1+S) where S = 2 x y
Integration Time (sec)
Sin
gle
Laye
r E
ffici
ency
Random errors only included in hand calculations and in GEANT/ITTF simulations
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The HFT – Pixel Technology
• Unique Features– 20.7 x 20.7 m pixels
– 100-200 sec integration time
– 436 M pixels
– 0.37% X/X0 per layer
– Install and Replace in 8 hours
• News– Change in process:
now using 400 cm moderate Resistivity Si
– Depletion voltage ~1V
– Better signal to noise and higher radiation tolerance >300 kRad, 1014 n/cm2
– Don’t have to replace the detector every year
Now using high resistivity Si
which allows for a biased
depletion region (previously
relied upon diffusion to collect
the charge)
22 cm
14 cm
8 cm
2.5 cm
.
HFT Si
SSD
IST
PXL2
PXL1
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Smart Pixels make the HFT unique
High efficiency detector wants high resistivity Si, CMOS cheap,
Smart electronics wants low resistivity Si for logic circuits
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Exploded view of the HFT inside the TPC
TPC Volume
OFCOuter Field Cage
IFCInner Field Cage
SSD
IST
PXL
FGT
HFT
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The “cone” assembly is removable (annually)
Forward GEM Tracker
Silicon Strip Detector(IST and HFT underneath)
Mechanics and electronics to support the HFT are underneath
4.2 Meters
~ 1 Meter
The SSD: 20 ladders located at a radius of 22 cm
Double sided Si strips, 95 m pitch, 4 cm long, crossed at 35 mrad
The electronics on each end of the ladder are to be upgraded
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The Old Silicon Strip Detector
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SSD Electronics
• New Ladder Card (left)
• Large FPGA on board
• Associated RDO in development
• Prototypes exist, moving to pre-production phase
• Trying to make it all fit
Goal: DAQ rate from 200 Hz 1 kHz
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Cone Installation
Cones installed Fall 2012
Shroud and OSC in place
Length ~4 m, Radius ~90 cm
SSD will sit on OSC
20 refurbished ladders around the circumference
Al mylar wrap covers the region over the SSD and between the shrouds
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Exploded view of the HFT inside the TPC
TPC Volume
OFCOuter Field Cage
IFCInner Field Cage
SSD
IST
PXL
FGT
HFT
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Prototype IST Staves (January 2012)
24 Staves at 14 cm radius
Intermediate between TPC/SSD and PXL
Prototype with Si modules and APV readout chips
Wire bonding is a success
Readout and electronics very similar to FGT
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• -1 ≤ Eta ≤ 1, full Phi coverage (TPC coverage)
• ≤ 30 µm DCA pointing resolution required for 750 MeV/c kaon– Two or more layers with a separation of > 5 cm.
– Pixel size of ≤ 30 µm
– Radiation length as low as possible but should be ≤ 0.5% / layer (including support structure). The goal is 0.37% / layer
• Integration time of < 200 μs
• Sensor efficiency ≥ 99% with accidental rate ≤ 10-4.
• Survive radiation environment.
• Air cooling
• Thinned silicon sensors (50 μm thickness)
• MAPS (Monolithic Active Pixel Sensor) pixel technology– Sensor power dissipation ~170 mW/cm2
– Sensor integration time < 200 μs (L=8×1027)
• Quick extraction and detector replacement (1 day)
PXL Requirements and Design ChoicesR
equi
rem
ents
Des
ign
Cho
ices
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Pixel support structure near the vertex
2.5 cm radius
8 cm radius
Inner layer
Outer layer
End view
Carbon fiber support beams
(green)
Two “D” sectors form the heart of the PXL detector. The two halves separate in order to allow for easy access, removal and repair.
25Jim Thomas - LBL
Hinge detail
• Parallelogram hinges support the two detector halves while sliding
• Cam and follower controls the opening of the hinges during insertion and extraction
• Detector support transfers to kinematic dock when positioned at the operating location
pixel support hinges
cam followers and linear camslide rails
sliding carriage
Reason for no bottom
Beam Pipe support…
kinematic dock
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HFT PXL status – fabrication and tooling
27Jim Thomas - LBL
Recent Progress – on many different scales
• PXL Insertion and Test Bed for installing the PXL detector into STAR
– Most Al parts become C fiber in the real thing
• A Hallmark of LBL Instrumentation is that things get tested before they are installed
• PXL Ladder “Cable” 2.5 cm by 30 cm
– Chips will go on lower 20 cm portion
– Prototype in Cu
– Final in Al to lower mass of ladder
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The PXL Engineering Run (Run 13)
• We are planning on a partial installation of PXL ladders for Run 13
– No SSD
– No IST
• Primarily an engineering run to test the PXL electronics and mechanics
– Some physics may be possible
– less efficient
Mercedes
Patch
Joined
Patch
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• D0 simulations by Jonathan Bouchet
• D0 input– 50k D0
– 0 < pT < 10
– -3 < < 3
– Basic cuts (pT > 0.1, < 1 ) 13K survive
• D0 output– Mercedes
970 events
– Joined 333 events
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Run 13 Engineering Run – Prospects for Physics
• D0 acceptance as a function of pT and patch geometry
• Overall breakdown and summary of acceptance
• Note: this does not include TPC tracking inefficiency nor pT dependent software cuts on the kinematics of the D0 … so the real world will be even more difficult
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PXL Detector Characteristics
Pointing resolution (12 19 GeV/pc) m
Layers Layer 1 at 2.5 cm radius
Layer 2 at 8 cm radius
Pixel size 20.7 m X 20.7 m
Hit resolution 6 m
Position stability 6 m rms (20 m envelope)
Radiation length per layer X/X0 = 0.37%
Number of pixels 356 M
Integration time (affects pileup) 185.6 s
Radiation environment 20 to 90 kRad
2*1011 to 1012 1MeV n eq/cm2
Rapid detector replacement ~ 1 day
356 M pixels on ~0.16 m2 of Silicon!
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Summary
• The HFT will explore the Charm sector at RHIC
• We will do direct topological reconstruction of Charm
• Our measurements will be unique at RHIC
• The key measurements include– V2
– Energy Loss
– Charm Spectra, RAA & Rcp
– Vector mesons
– Angular Correlations
• The technology is available on an appropriate schedule
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Backup Slides
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FY09 FY10 FY11 FY12 FY13 FY14 FY15
HFT Construction
HFTOperation
MTDConstruction
MTDOperation
HLT Development
HLT Operation
Finish HFT in time for the 2014 run
Finish MTD project by Mar, 2014 and make 80% of the full system ready for year 2014 run
HLT is seeking funds but is projected to be under development through FY15,
and will be available for physics at all times
Three STAR Upgrade Projects
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Radiation Load expected in 2014
Radcm 2.5 2.5 14.0 22.0 2.5 2.5 14 22
# of wks
Physkrad
Phys+ UPC krad
Physkrad
Physkrad
Ramp and Totalkrad
Ramp and Total n/cm2
Ramp and Total krad
Ramp and Total krad
200 GeV
Au + Au Max 12 28.3 59.8 0.9 0.4 88.0 1.1E+12 1.8 0.7
Au + Au Min
12 5.3 11.3 0.2 0.1 16.6 0.2E+12 0.3 0.1
500 GeV
p + p Max 12 133.3 133.3 4.3 1.7 266.7 5.3E+12 8.5 3.4
p + pMin 12 28.9 28.9 0.9 0.4 57.8 1.1E+12 1.8 0.7
36Jim Thomas - LBL
Efficiency Calculations in a high hit density environment
The probability of associating the right hit with the right track on the first pass through the reconstruction code is:
P(good association) = 1 / (1+S)
where S = 2 x y
P(bad association) = (1 – Efficiency) = S / ( 1 + S )
and when S is small
P(bad association) 2 x y
x is the convolution of the detector resolution and the projected track error in the ‘x’ direction, and is the density of hits.
The largest errors dominates the sum
x = ( 2xp + 2
xd )
y = ( 2yp + 2
yd )
Asymmetric pointing resolutions are very inefficient … try to avoid it
37Jim Thomas - LBL
TPC Pointing at the PXL Detector
• The TPC pointing resolution on the outer surface of the PXL Detector is greater than 1 mm … but lets calculate what the TPC can do alone
– Assume the new radial location at 8.0 cm for PXL-2, with 9 m detector resolution in each pixel layer and a 200 sec detector
– Notice that the pointing resolution on PXL-1 is very good even though the TPC pointing resolution on PXL-2 is not so good
• The probability of a good hit association on the first pass– 55% on PXL2
– 95% on PXL1
Radius PointResOn(R-)
PointResOn(Z)
Hit Density
8.0 cm 1.4 mm 1.5 mm 6.0
2.5 cm 90 m 110 m 61.5
This is a surprise: The hard work gets done at 8 cm!
The purpose of the intermediate tracking layers is to make 55% go up to ~100%
All values quoted for mid-rapidity Kaons at 750 MeV/c
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• Does charm flow hydrodynamically?– Heavy Flavor Tracker: unique access to low-pT fully reconstructed charm
• Are charmed hadrons produced via coalescence?– Heavy Flavor Tracker: unique access to charm baryons– Would force a significant reinterpretation of non-photonic electron RAA
• Muon Telescope Detector: precision measurements of J/ψ flow
Properties of the sQGP
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Rapid Insertion
During this operation the PXL box rests on two 6 inch aluminum box beams. These beams are supported independent of walking platform
Each half of the PXL detector is supported on two round slide rails both in the PXL storage box and in the MSC.In this procedure the box most be accurately moved into position to align the slide rails of the box with the rails in the MSC
Up dated, includes measurement tool for checking alignment of two rail systems and instructions
40Jim Thomas - LBL
Calculating the Performance of the Detector
• Billoir invented a matrix method for evaluating the performance of a detector system including MCS and dE/dx
– NIM 225 (1984) 352.
• The ‘Information Matrices’ used by Billoir are the inverse of the more commonly used covariance matrices
– thus, ’s are propagated through the system
• The calculations can be done by ‘hand’ or by ‘machine’ (with chains)
• STAR ITTF ‘machine’ uses a similar method (aka a Kalman Filter)– The ‘hand calculations’ go outside-in
– STAR Software goes outside-in and then inside-out, and averages the results, plus follows trees of candidate tracks. It is ‘smart’ software.
MCS D M MCS D M MCS
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Hand Calculations .vs. GEANT & ITTF
- - - - PXL stand alone configuration
Paper Proposal configuration
GEANT & ITTF adjusted to have the correct weights on PXL
layers
Updated configuration … no significant changes in pointing at
VTX
TPC alone
Full System
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Flow: Probing Thermalization of the Medium
py
)(tan,2cos 12
x
y
p
pv
Coordinate space: initial asymmetry
Momentum space: final asymmetry
pxx
y
Semiperipheral collisions
Signals early equilibration (teq 0.6 fm/c)
43Jim Thomas - LBL
Flow: Constituent Quark Number Scaling
In the recombination regime, meson and baryon v2 can be obtained from the quark v2 :
2 2 2 2v22
v3
v3v Btt
q tM q tp ppp
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Scaling as a Function of (mT – m0)
• The light quark sector scales beautifully with v2/nq .vs. (mT – m0)/nq
– Note that pT < 1 GeV always did scale !
• The strange quark sector also scales with <v2> and the scaling holds at all centralities
• Even the meson
V2 /
nq
Does it work in the Charm Sector?
A strong test of the theoryYuting Bai, QM 2006 for the STAR Collaboration
STAR Preliminary work by Yan Lu
45Jim Thomas - LBL
Baryons vs. mesons
• Coalescence and fragmentation conspire at intermediate pT to give constituent quark number scaling and Baryon-Meson differences.
• Coalescence and fragmentation of charm quarks is different than for light quarks … so it is a strong test of the theory
• Coalescence of light quarks implies deconfinement and thermalization prior to hadronization
• How do baryons and mesons behave in the Charm sector?
• The Λc will be a fascinating test … and we might be able to do it with the HFT via Λc / D
46Jim Thomas - LBL
“Heavy Flavor” is the next frontier at RHIC
• A low viscosity, sQGP is the universally accepted hypothesis
• The next step in confirming this hypothesis is the proof of thermalization of the light quarks in RHIC collisions
• The key element in proving this assertion is to observe the flow of charm … because charm and beauty are unique in their mass structure
• If heavy quarks flow– frequent interactions among all quarks
– light quarks (u,d,s) likely to be thermalized
Current quark: a bare quark whose mass is due to electroweak symmetry breaking
Constituent quark: a bare quark that has been dressed by fluctuations in the QCD sea
47Jim Thomas - LBL
Hints of Elliptic Flow with Charm
Shingo Sakai, QM 2006 for the PHENIX Collaboration
• D e +X
Single electron spectra from PHENIX show hints of elliptic flow
Is it charm or beauty?
• The HFT will cut out large photonic backgrounds:
e+e-
and reduce other large stat. and systematic uncertainties
• STAR can make this measurement with 50 M Au+Au events in the HFT
• Smoking gun for thermalization at RHIC!
Better if we can do direct topological identification of Charm
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Heavy Flavor Energy Loss … RAA for Charm
• Heavy Flavor energy loss is an unsolved problem
– Gluon density ~ 1000 expected from light quark data
– Better agreement with the addition of inelastic E loss
– Good agreement only if they ignore Beauty …
• Beauty dominates single electron spectra above 5 GeV
• We can separate the Charm and Beauty by the direct topological identification of Charm
Theory from Wicks et al. nucl-th/0512076v2
Where is the contribution from Beauty?
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A Rich Physics Program
• There is a rich physics program when all of the STAR physics detectors are working together
– Flow in the Charm sector
– dE/dx in the Charm sector
– Recombination and RAA in the Charm sector
– Vector Mesons
– Charm Angular Correlations
– non-photonic electrons
– …
50Jim Thomas - LBL
The Simplest ‘Simulation’ – basic performance check
• Study the last two layers of the system with basic telescope equations with MCS
– PXL 1 and PXL 2 alone ( no beam pipe )
– Give them 9 m resolution
0
( / )13.6mcs
MeV c x
p X
2 22 2 2 22 11 2 2 1
2 2
2 1sin ( )mcs rr r
r r
hh
• In the critical region for Kaons from D0 decay, 750 MeV to 1 GeV, the PXL single track pointing resolution is predicted to be 20-30 m … which is sufficient to pick out a D0 with c = 125 m
• The system (and especially the PXL detector) is operating at the MCS limit
• In principle, the full detector can be analyzed 2 layers at a time …
TPC alone
PXL alone
51Jim Thomas - LBL
– Goal: graded resolution and high efficiency from the outside in
– TPC – SSD – IST – PXL
– TPC pointing resolution at the SSD is ~ 1 mm
– SSD pointing at the IST is ~ 400 m (200 x 800)
– IST pointing at PXL 2 is ~ 400 m (200 x 800)
– PXL 2 pointing at PXL1 is ~ 125 m (90 x 175 )
– PXL1 pointing at the VTX is ~ 40 m (Kaon at 750 MeV)
Overview & Goals for Si Detectors Inside the TPC
The challenge is to find tracks in a high density environment with high efficiency because a D0 needs single track 2
~ 50 cm
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Graded Resolution from the Outside In
• A PXL detector requires external tracking to be a success– The TPC and intermediate tracking provide graded resolution from the
outside-in• The intermediate layers form the elements of a ‘hit finder’
– The spectral resolution is provided by the PXL layers• The next step is to ensure that the hit finding can be done
efficiently at every layer in a high hit density environment
TPCvtx
PXL alone
TPCSSDSSDISTISTPXL2PXL2PXL1PXL1VTX
53Jim Thomas - LBL
Central Collisions: Density of hits on the Detectors
dN dN d
dz d dz
2 2
1( , )
dr z
dz r z
where
22
1 700( ) 17.8
2 2
dN dNCentral cm
dA dz r r
Au+Au Luminosity (RHIC-II) 80 x 1026 cm-2s-1
dn/d (Central) 700 dn/d (MinBias) 170 MinBias cross section 10 barns MinBias collision rate (RHIC-II) 80 kHz Interaction diamond size, σ 15 cm Integration time for Pixel Chips 200 sec
Radius Simple Formula|| = 0
|| < 0.2 || < 1.0
PXL 1 2.5 cm 17.8 cm-2 19.0 cm-2 15.0 cm-2
PXL 2 8.0 cm 1.7 cm-2 1.8 cm-2 1.5 cm-2
IST 14.0 cm 0.57 cm-2 0.66 cm-2 0.52 cm-2
SSD 23.0 cm 0.21 cm-2 0.23 cm-2 0.19 cm-2
The density of hits is not large compared to the number of pixels on each layer. The challenge, instead, is for tracking to find the good hits in this dense environment.
Slightly
conservative
numbers
100,000
pixels cm-2
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MinBias Pileup – The PXL Layers Integrate over Time
A full study of the integrated hit loading on the PIXEL detector includes the associated pileup due to minBias Au-Au collisions and the integration time of the detector.
2022
00
1 1( , , , )
2 ( )2
za
a
dN dN dMinBias z r ZDC e dz
dA d r d z z
2022
02 20
2720 1 1( , , , )
2 2 ( )
za
a
dNMinBias z r e dz
dA r r z z
PIXEL-1 Inner Layer
PIXEL-2 Outer Layer
Radius 2.5 cm 8.0 cm Central collision hit density 17.8 cm-2 1.7 cm-2
Integrated MinBias collisions (pileup) 23.5 cm-2 4.2 cm-2
UPC electrons 19.9 cm-2 0.1 cm-2
Totals 61.2 cm-2 6.0 cm-2
Pileup is the bigger challenge
Integrate over time and interaction diamond
200 sec
Not insignificant
55Jim Thomas - LBL
A Quick Note About Absolute Efficiencies
• The previously quoted efficiencies do not include the geometric acceptance of the detectors
• The TPC has an approximately 90% geometric acceptance due to sector boundaries and sector gaps
– In addition, the TPC has an additional ~90% efficiency factor at RHIC II luminosities … this is a software and tracking issue due to the large multiplicity of tracks
• The SSD has an approximately 90% geometric acceptance due to areas where the crossed strips don’t achieve full coverage
• All ‘new’ detectors are assumed to have 100% geometric acceptance
• Efficiency from the previous slide– 0.98 x 0.98 x 0.93 x 0.94 = 0.84
• Geometric acceptance and TPC track finding efficiencies– 0.9 x 0.9 x 0.9 = 0.73 In this example Total = 0.61
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Single Track Efficiencies – Hand Calc .vs. ITTF
The efficiency for finding tracks in central Au+Au collisions in the STAR TPC and the HFT. Finite acceptance effects for the TPC and SSD are included in the simulations. The quoted efficiency from GEANT/ITTF is for || < 1.0 and for tracks coming from the primary vertex with |vz| < 5 cm.
Hand Calculations
Hand calculations assume the acceptance is flat in pT and assume a single track at = 0.5
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D0 Reconstruction Efficiencies Compared
Geant/ITTF
• The predicted absolute efficiency of the HFT detector. – The red squares show the efficiency for finding the D0 meson with the full set
of Geant/ITTF techniques.
• The green line shows the D0 efficiency predicted by the Geant/ITTF single particle efficiencies
• The blue line shows the D0 efficiency predicted by the hand calculations– Single track efficiencies for the kaon and pion are integrated over the Lorentz
kinematics of the daughter particles to predict the D0 efficiency
• Hand Calculation give guidance … but more complex questions should be answered by the full suite of tools available to Geant/ITTF
Hand Calculations
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A Robust Design
There is a rich physics program that can be addressed with the HFT in STAR
• The HFT is thin, unique, innovative and robust
• The designs have been tested extensively with hand calculations and more carefully with specific examples tested with GEANT/ITTF simulations
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The Pixel Detector lies beneath the SSD and IST
60Jim Thomas - LBL
Kinematic Mounts
• Kinematic mounts exploit the fact that three points define a plane
• Obvious ‘perfect’ alignment with four spheres 3 points of contact
• Reproducible position to 10 m, often used on optical benches
• More typical design on the right … the difficult part is to maintain enough pressure on the points of contact to hold their position
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Hinge and Cooling Duct detail
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Air Cooling
Silicon power: tested at 170 mW/cm2 (~ power of sunlight) 350 W total in the ladder region (Si + drivers)
computational fluid dynamics
Air-flow based cooling system for PXL to minimize material budget.
Detector mockup to study cooling efficiency
ladder region
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MSCPixel Insertion TubePixel Support Tube
IDSEast Support CylinderOuter Support CylinderWest Support Cylinder
PIT
PST
ESC
OSC
WSC
Shrouds
Middle Support Cylinder
Inner Detector Support
Structures: Exploded Detail
Assemble using bolted interfaces
MSC installed into IDS after IDS assembled (detectors not shown)
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Stability Performance
• IDS analyzed for deflection
• Anticipated response convolved with measured STAR vibration environment
• RMS Stability under 10 m
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East Pole Tip as seen during a summer shutdown
Beam-Beam counter installed in East Pole Tip
View of Existing East Pole Tip Area
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The Silicon Strip Detector – an existing detector
• 20 ladders located at a radius of 22 cm
• Double sided Si strips, 95 m pitch, 4 cm long, crossed at 35 mrad
• The electronics on each end of the ladder are to be upgraded
• Readout Goal: > 1 kHz for all detectors in the HFT