Vasily Dzhordzhadze University of California, Riverside for PHENIX Collaboration

Extending Physics Capabilities of the PHENIX Detector with Calorimetry

at Forward Rapidities

Vasily Dzhordzhadze University of California, Riverside

for PHENIX Collaboration21st Workshop on Nuclear

DynamicsBreckenridge, February 05-12,

2005

02/11/2005 V.Dzhordzhadze

21st Winter Workshop on Nyclear Dynamics

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PHENIX Detector



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RHIC Executive Summary

• Energy densities: Maximum dEt/d600 GeV at mid rapidity -> Initial > 5 GeV/fm3 > cr

• Elliptical flow: Strong elliptical flow v2 consistent with short thermalization times 0 ~ 1 fm/c

• Soft particle spectra: shapes & and yields consistent with hydrodynamic source emission. Particle ratios consistent with chemically equilibrated system before hadronization

• Hard particle spectra: strong pT suppression in central A+A (relaive to pp,pA & pQCD) consistent with final-state partonic energy loss in dense system: dNg/dy~1100

• Intermediate pT spectra: Enhanced baryon yields & v2 (compared to meson) consistent with quark recombination mechanisms in a thermal and dense matter

• All observations are consistent with formation of thermalized strongly interacting matter in central Au+Au collisions



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The Challenges to the Next Decade

• Move from exploration of new matter formed in A+A collisions to study of its property

• Accelerate progress in the developing spin program• Upgrade Detectors: Increase acceptance, Implement

vertex tracking, Implement jet measurment• Upgrade RHIC: X40 increase Luminosity

• PHENIX central arms : 900 in azimuth and ||<0.35

• PHENIX muon arms : full azimuth coverage and 1.2< ||<2.4



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Upgrades to PHENIXEnhanced PID: TRD-East (x)Aerogel/TOF West (x)

Vertex Spectrometer:Flexible Magnetic Field (x)Silicon vertex trackerTPC/HBD/GEM

Forward SpectrometersNew muon trigger chambersForward silicon detectorsForward Nosecone calorimeters

pA centrality detectorsVery forward hadron calorimeter(x)

DAQ/Trigger



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PHENIX Forward Muon Upgrade presented by Xie Wei at this Workshop



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Problems:

-only 40 cm apart from collision point …

-only 20 cm of space is available … and then …3.5

Labs of dead material downstream

Layout: PHENIX forward spectrometers

FST



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Goals for the W-Si Nosecone Calorimeter

• Precision measurement of the EM showers• Effective 0 discrimination• Good hadron separation• Jet finding and coarse jet energy

measurement• Ability of fast triggering• Nosecone coverage : full (3600) in azimuth

and 0.9<||<3.5



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Existing Technology Today: PAMELA



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e+e–ZH, Z at s=500 GeV

HCALCOIL

ECAL

Structure 1

Structure 2

Structure 3

62 mm

Silicon wafers with 6×6 pads (10×10 mm2)

62 m

m

200mm

360mm

LAL,LLR,LPC,PICM

Imperial College, UCL, Cambridge,Birmingham, Manchester, RAL

ITEP,IHEP,MSU

Prague (IOP-ASCR)

SNU,KNU

CALICE ECAL CALICE ECAL

360mm

Future: TESLA / CALICE



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““coarse” (leakage) compartmentcoarse” (leakage) compartment““fine” (electromagnetic) compartmentfine” (electromagnetic) compartment

00// identifier (Si strip layers) identifier (Si strip layers)

Photon Photon converter converter sectionsection

Shower maxShower max sectionsection

Si pad sensor Si pad sensor layerslayers

Tungsten absorber (16 mm)Tungsten absorber (16 mm)

Tungsten absorber (2.5 mm)Tungsten absorber (2.5 mm)

Ideas



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front view side view

40 cm

20 cm

/0

identifier

EMhadronic

Incoming electron (10GeV)

First 8.5cm: 16 layers of Tungsten (2.5 mm), Si(0.3 mm), First 8.5cm: 16 layers of Tungsten (2.5 mm), Si(0.3 mm), G10(0.8 mm), Kapton (0.2 mm) and Air(1.2 mm). G10(0.8 mm), Kapton (0.2 mm) and Air(1.2 mm).

– After first 6 layers there is a 0.5mm thick double layer of Si,G10,Kapton,Air (this is the /0 identifier).

Second half has a 6 layers with same sequence of materials, only Second half has a 6 layers with same sequence of materials, only thickness of Tungsten 16 mm.thickness of Tungsten 16 mm.

10 GeV electron



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Resolution for 1,5,10,40 GeV electron

11 5

10 40



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e 10 GeV

Electromagnetic Electromagnetic shower shower measurementsmeasurements

Expected Performance

E1/2

~ 20%*sqrt(e)



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2 Concept of Pion Rejection

2 = (Ei-Ee)2/2i i =1,3

2



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Mul

tiplic

ity p

er

even

t

Hadronic shower Hadronic shower rejectionrejection

++, 40 GeV/c, 40 GeV/c


100 K Simulated

4.5 K Selected

Momentum GeV/c

Momentum GeV/c



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Pion Rejection

Momentum GeV/c



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JetsJets




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Digitizer Boards

NCC readout location on

the surface of magnet pole

Central tracking communication lines

Living Together …



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Item Total

W 1.8 t

Si (calorimeter) 14 m2

Si (-0 identifier) 1.15 m2

Readout units (calorimeter) 288

Readout units (-0 identifier) 24

Sensors (16 pixels) 3776

SVX4 48

Digitization (subtowers) 8448

NCC Mechanical Concept



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receiver digitizerDelay/

event buffers

Smart DCM’s

NCC L1 trigger boardGlobal Trigger Sums

Digitize signal as early as possible

Generate low level trigger sums from the reduced bit ADC output locally

Generate regional triggers locally

receiver digitizerDelay/

event buffers

TriggerTrigger

NCC Readout Concept (Chi)



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4” High resistive wafer : 5 K4” High resistive wafer : 5 Kcmcm

Thickness : 300 microns Thickness : 300 microns 3 % 3 %

Tile side : 62.0 + 0.0Tile side : 62.0 + 0.0

- 0.1 mm- 0.1 mm

Guard ringGuard ring

In Silicone ~80 e-h pairs / micron In Silicone ~80 e-h pairs / micron 24000 e24000 e-- /MiP /MiP

Capacitance : ~40 pFCapacitance : ~40 pF

Leakage current : 5 – 15 nALeakage current : 5 – 15 nA

Full depletion bias : ~100 VFull depletion bias : ~100 V

Nominal operating bias : 200 VNominal operating bias : 200 V

One wafer is a Matrix of 4 x 4 pixels of 2.25 cm2.Important point : manufacturing must be as simple as possible to be near of what could be the real production for full scale detector in order to :

• Keep lower price (a minimum of step during processing)• Low rate of rejected processed wafer• good reliability and large robustness

Sensors



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Flex Cable

Readout unit

Si Sensor

256 analog lines

Interconnect Interconnect boardboard

PA boardPA board

-This is the calorimeter – all pads in the subtower are This is the calorimeter – all pads in the subtower are contributing to signal;contributing to signal;

-Noise budget is set by physics: better is an enemy of the Noise budget is set by physics: better is an enemy of the good; good;

NCC Signal packaging Concept



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11/ 8/ 2004 V.Dzhordzhadze 4

Dynamic range [GeV] ~100 Kinematical limit

MIP signal in a single Si layer (e)

24k ~300 mkm Si

MIP signal in a subtower (e)

144k-240k 6 to 10 Si layers

Max. charge per event in a subtower(e)

2.1 108 or ~ 40 pC 50 GeV deposition, 1.7% sampling fraction

Dynamic range >10000 MIP>1000 MIP10

MIP10 is the signal summed up over all contributing layers (10 layers max)

Underlying event Underlying event contribution can be contribution can be

neglected even in the neglected even in the central AuAu collisionscentral AuAu collisions

Readout: Dynamic Range



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Compartment I II III

Sampling layers 6 10 6

Sampling fraction (%) 1.7 1.7 0.26

MIP energy loss [MeV] 42 69 270

MIP energy loss in Si [MeV] 0.7 1.2 0.7

Pad capacitance [pF] 80 80 80

Trace capacitance [pF] 10-45 10-45 10-55

Tower capacitance [pF] 540-780 900-1300 540-900

Energy range of interest [GeV]

0.5 – 50

Intrinsic energy resolution (em showers) [GeV]

0.4-1.5

Noise limit 10 MeV 15 MeV 100 MeV

ENC budget [MeV] 0.15 0.2 0.15

ENC budget [electrons] 40 k 50 k 40 k

Readout: Noise Budget



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• Classical CSA followed by 4-th order shaper was modelled with PSPICE;

• Rise time and shaping time were optimized to achieve optimum noise performance for any given base-to-base (1% level) pulse length on the ADC input;

40k limit40k limit

PYTHIA: PYTHIA: the probability for tower the probability for tower to receive a direct hit in to receive a direct hit in the pp minimum bias the pp minimum bias

event is ~3%event is ~3% GEANTGEANT

Shower spreading results Shower spreading results in the tower occupancy in the tower occupancy increased to 10%increased to 10%

Base line Base line restoration in 300 restoration in 300

nsns

Readout: Base restoration and signal shaping



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2004 2005 2006 2007 2008 2009 ….

pp 5+1 5+10 5+11 0 5+9 156pb-1

√s= ……………………….. 200 GeV ………………….........|

P= 0.45 0.5 0.7 ………………………………………….

Inclusive hadrons Charm Physics direct photons Jets W-physics

ALL(hadrons) ALL(charm)

ALL(γ) AL(W)

L= 6x1030cm-2s-1 8x1031cm-2s-1

Schedule



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• Ongoing R&D program is funded by UCR (R.Seto) and BNL (PHENIX Upgrade Funds)

– Prototype• pad-sensors, analog cables, readout units, front-end - MSU;• strip-sensors for the g/p0 identifier – Prague. Backup solution - from earlier project in

Trieste;• Readout for g/p0 identifier – SVX4 (Prague). Backup solution – same as in the calorimetric

layers (MSU).

• Preamplifier (decision for CDR)– New device developed at BNL;– Upgrade to CR3A developed as part of R&D program in Trieste – preferred but

….. ;– Upgrade to preamp developed as part of TESLA/CALICE program – under

investigation;– New device developed in collaboration between MEPhI/MSU/BNL – proposal exists;– Just new device (dreams exist).

• Mechanics of the future detector (prototype and CDR)– Work started in Dubna (A.Litvinenko).

• Digital readout (CDR)– New group from Dubna (S.Bazylev) will be helping with CDR

Near Term Priorities



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o PHENIX has great plans for a program of new physics aimed to study nuclear effects in partonic structure functions down to a very small partonic momenta. It spans the whole range of pp (including polarized), pA and dA collisions at RHIC.

o Integrated forward spectrometer upgrade is the precondition for PHENIX to stay competitive in this new field of physics.

o We have technical solutions which match physics and present an excellent opportunity for new groups both in physics and instrumentation!

Summary

Vasily Dzhordzhadze University of California, Riverside for PHENIX Collaboration

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