david l. winter for the phenix collaboration phenix silicon detector upgrades rhic & ags annual...

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David L. Winter for the PHENIX Collaboration PHENIX Silicon Detector Upgrades RHIC & AGS Annual Users' Meeting Workshop 3 RHIC Future: New Physics Through Upgrades 27 May 2008

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David L. Winterfor the PHENIX Collaboration

PHENIX Silicon Detector Upgrades

RHIC & AGS Annual Users' MeetingWorkshop 3

RHIC Future: New Physics Through Upgrades27 May 2008

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 2

Outline

Motivation

Design

Schedule and Status

Summary

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 3

Motivation

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 4

Physics goalsImprove vertex resolutionImprove p resolutionImprove high-pT trackingMeasure reaction planeSuppress background

Enabling:Separate measurement of production and flow of charm and beautyStudy of production and suppression of quarkoniaStudy of q, g contribution to proton spin

Using signals:b B , ec D , eJ/’ +-, e+e-

Hadrons

e-

e+

+

-

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 5

Signals and Backgrounds

The problem(s):Backgrounds (, K , e) dominate the signal

Cannot easily distinguish single leptons from those produced from charm, bottom

Central arms: electronsForward arms: muons

Simulated RHIC-II p+p run

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 6

Separating Signal from Background

Mean , K e decay distance is large

D, B mesons travel some distance before semileptonic decay to or e

Prompt e have 0 DCA

c

D0 125 m B0 464 mD± 317 m B± 496 m

K± 3.7 m ± 7.8 m

Separate D, B decays from prompt leptons and from long-lived decays from , K by measuring the DCA to the primary vertex

e-

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 7

Design

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 8

Design SpecificationsNeed sufficient DCA resolution

Central: ~ 50 m

Forward: ~ 100 m

Need low enough occupancy to find tracks in central AuAu events (<few %)

Need enough hits to reconstruct a track ( 3 hits)

Need to match tracks with Central arm detectors: ||= 0.35

Muon system: || = 1.2 - 2.4

Large solid angle coverage

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 9

Detectors

.

Barrel vertex detector (VTX)

Forward vertex detectors (FVTX)

80 cm

40 cm

38 cm

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 10

Barrel Pixels (Layers 1 & 2)2 Pixel buses per ladder

30 ladders in 2 cylindersPixels: 50 x 425 m2 150 m - thick SiliconR = 2.5 and 5.0 cmLength = 22 cmReadout:

1.3 and 2.6M channelsALICE1LHCb chipFull bus readout in ~50 sFast-OR available for Lvl-1 trigger

Rad Len 1.44% total

LadderSPIRO Board

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 11

Barrel Stripixels (Layers 3 & 4)Based on sensor design by BNL InstrumentationEffective pixels: 80 x 1000 m2 650 m - thick SiliconR = 10 and 14 cm44 Total laddersLength = 32 and 38 cm140K and 280K channelsReadout with SVX4 chipRad Len 2.7% total

Single sided, 2D readout

Strip pixel sensor wafer made by HPK

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 12

Endcap Strips (Eight Stations)

4 disks / side 48 wedges/disk75 um strips,2.8-11.2 mm long1664 strips/column1.1M channels totalReadout with FPHX chip

7.5°

HDI

Detector

FPHX Chips

Backplane

Rigid, thermally conductive epoxy

Rigid epoxy

~10 cm

2.8mm

11.2mm

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 13

Endcap Readout: FPHX chip

128 Channels (strips)Signal polarity: positive (holes)Gain at shaper output: 50 mV/fC3-bit ADCNominal peaking time: 60 nsNoise: 110e + 196 e/pFData push architectureOutput 4 hits in 4 beam clocksPower: ~600 uW per channel for maximum input transistor bias current

128 input bond padsin a double row

32 I/O pads in a single row

9 mm

1.2 mmDevelopment by FNAL, Based on FPIX design from BTeV

FPHX placement on wedge

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 14

Mechanical Design

Single integrated VTX-FVTX mechanical structure being designed by HYTECTwo half-cylinder shellsServices routed top/bottom (VTX) and out ends (FVTX)Electronics mounted on “big wheel(s)”New, smaller diameter beam-pipe

FVTXBigWheel

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 15

Schedule and Status

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 16

Construction Schedule

Barrel construction well underwaypixel layers completion in 2009

stripixels completion in 2010 (first ladders)

Forward detector construction started in FY08, installation to be in 2011

2008 2009 2010 2011 2012

VTX

FVTX

R&D Phase Construction Phase Ready for Data

pixels stripixels

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 17

Pixel Ladder Bus

1.5cm bus before assembly

Fine pitch detail of the bus

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 18

Pixel Ladder Bus

Assembled Ladder

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 19

Cosmic Ray Telescope

Ladders and SPIRO Boards

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 20

Pixel Bus Cosmic Ray TestsComic Ray telescope with 3 pixel busesBoth external trigger and fast-OR triggerUsed complete readout chain.Last test- Sept. ‘07

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 21

Pixel Source Test

Use source to illuminate sensor module on 1/2-ladder

Self-trigger using readout chip Fast-OR

100K events

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 22

StatusPIXEL Ladders:

Cosmic ray events observed, Sept '07Ladder production to start in 20082 Barrels ready for installation in 2009, Run 10

STRIPIXEL Ladders:Readout-Card Prototyping in progress.First Ladders ready for installation in 2010, Run 11Full detector ready in 2011, Run 12

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 23

Construction Status: FVTX

Mechanical design ~ 80% completeFirst prototype FPHX submission is very soon (June)HDI under developmentDAQ readout electronics have been prototyped

Prototype DAQ Electronics

Thermally conducting silicone

Honeycomb support panel

Wedges front and back

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 24

Performance: VTX

Simulated Au+AuAfter 2<1 cut, DCA distributions of light hadrons and D0 decay are clearly separated

D0 decay

Collision vertex

~ 40 m

Single with 3<pT<4200 thick pixel layers650 thick stripixel layersPassive material is:

1.0% pixel2.75% stripixel

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 25

Performance: FVTX

improved background rejectionImproved mass resolutionSeparate ’

100 m

DCA – R component

DCA – component

300 m

DCA metric“Perfect” track finding

Kalman filter fit

Includes VTX hits

With FVTX

Without FVTX

p+p MB Au+AU

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 26

Open Charm, Bottom Signals

Nuclear Modification Factor expected with VTX

• VTX to separately measure RAA of be and ce• Same goal for FVTX (e )

• factor 4-5 suppression!(?!)• perturbative QCD?

Nuclear Modification Factor without VTX

PHENIX: PRL 98, 172301 (2007)

single electrons from heavy flavor decay

27 May 2008 David Winter 2008 RHIC&AGS Annual User's Meeting 27

SummaryThe VTX and FVTX detectors have been proposed, approved, and being constructed to address heavy-flavor physics

Large coverage (2 @ 1.2<||<2.4 and nearly 2 @ ||<0.35

Improved tracking and resolution

These projects will enableStudy of heavy-flavor production and flow (charm and bottom separately)

Study of quarkonia production and suppression

Study of contribution to proton spin

Greatly improved background suppression

Construction is underway for both detectorsInner barrels installed by 2009

Outer barrels installed by 2010/2011

Endcaps installed by 2011