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Solid State Detectors for Upgraded PHENIX Detector at RHIC. Bits of history. 2003 - Maturity and planning for the next 10-15 years Precision measurements, extended coverage. FCAL. 1991 – Project Inception 1997 – First ion collisions in RHIC 2002 – statements of major discovery. SMD/. FCAL.
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Bits of history 2003 - Maturity and planning for the next 10-15 years Precision measurements, extended coverage FCAL 1991 – Project Inception 1997 – First ion collisions in RHIC 2002 – statements of major discovery SMD/ FCAL
Solid State Upgrade components • Central Barrel Silicon Tracker • Two layers of pixels (ALICE); • Two layers of StriPixels; • Forward Silicon Trackers (South and North) • Four layers of silicon discs (short strips with pixel-type readout) each; • Forward W-Si Calorimeters (South and North) • 22 layers of 6x6 cm2 pad sensors (15x15 mm2 pads); • One layer of StriPixel Detectors (0.5 x 60 mm2 strips)
Barrel VTX Detector • Specifications • 4 layers with large acceptance (Df ~ 2 p&|h| < 1.2) • Displaced vertex measurement : s < 40 mm • Charged particle tracking : sp/p ~ 5% pat highpT • Working detector for both of heavy ion and pp collisions • Technology Choice • Hybrid pixel detectors in 2 inner layers • Stripixel sensors w/ SVX4 readout chip in 2 outer layers Pixel layers r=5.0 cm, Δz~±10 cm r=2.5 cm, Δz~±10 cm Beam pipe Strip layers r=10.0 cm, Δz~±16 cm r=14.0 cm, Δz~±19 cm
Barrel: Pixel Detectors Pixel detector • Technology choice: • ALICE1LHCb read-out chip 32 x 256 ch / chip • 4 chips bump bonded to sensor with pixel size: 50 m x 450 m • Grouped to ladders • Readout through pilot module • R&D with ALICE and NA60 • Adapt technology to PHENIX • Detectors operated in NA60 Readout Bus Sensor Readout chip Support/cooling Half ladder PILOT module Read out Bus From pixel Optical I/O data clock & control Optical link driver chip (GOL) Analog PILOT (control, etc) digital PILOT (read pixel data) Optical package NA60 In-In collision taken 2003
Barrel: Strip Detector Z. Li, NIMA518, 738 (2004) x3’ u1 x2’ u2 u1’ x1’ u3 x1 x3 u1’ u2’ x2 CV IV • Strip sensor • BNL’s new “stripixel” concept : single-sided sensor w/ 2-D position sensitivity • Charge sharing by 2 spirals in one pixel (80 μm ×1000 μm) & projective x/u-strip readout • Pre-production sensor (Hamamatsu) • p+/n/n+ structure • 3.5×6.4 cm2 • 625/500 μm thickness • Spiral : 5/3μm line/gap • Pixels : 384×30×2=23,040 • Strips : 384×2×2=1,536 • Probing tests are on-going for evaluation
Calorimeters: Sampling cell design • Detector ladder glued to the W plate • To avoid • draining bulk current into electronics; • loss of electronics whenever channel trips; • and to save space • Thin film technology used to implement rc-chip on interconnect board Sensors carrier board Absorber (W)
Calorimeters: solution to decoupling Al SiO2 SiO2+Si3N4 p+ n+ Al bias strip AC Coupled Si Detector Polysilicon bias resistors 30% extra cost $160 -> $240 for 6x6 cm2 detector
Prototype Silicon Wafers For Calorimeter 62 mm 62 mm Si Wafer :4x4 pads of detection (15x15 mm2) 4” High resistive wafer : 5 Kcm Thickness : 300 microns 3 % Tile side : 62.0 + 0.0 - 0.1 mm Guard ring In Silicone ~80 e-h pairs / micron 24000 e- /MiP Capacitance : ~80 pF Leakage current : 5 – 15 nA Full depletion bias : ~100 V Nominal operating bias : 150 V • ELMA: • Well established technology; • Long production history • Good reputation
Calorimeters: g-p0 identifier Y 500 m RC Test structure mask SVX4 RC SVX4 X
Upgrade Schedule Scenario R&D Phase Construction Phase Ready for Data
Stripixel Sensor : Principle • A novel “stripixel” detector concept innovated by BNL Instr. Div. : Z. Li, NIMA518, 738 (2004). • Single-sided sensor • 2-dimentional position sensitivity by charge sharing • Two independent electrodes interleaved in one pixel are projectively read out by strips. • Advantages (compared with a double-sided strip sensor) • Simple structure : reduce costs and integration issues • Radiation hard (cf. a complicated n+ side structure in a double-sided strip sensor) • Disadvantages • Large capacitance/strip due to the interleaving scheme • Decrease in S/N due to charge sharing
Silicon Strips Detectors for Central Tracker 2nd Metal X - pixel U - strip Go to (1 st metal) Bonding Pad for U - strip U - pixel (1 metal) st 2nd Metal X - strip mm 80 Bonding FWHM Pad for for charge X - strip mm 1000 diffusion Z. Li, Inst. Div., BNL Sensor structure • Sensor technology choice: • Single sided, two dimensional read-out sensor developed by Z. Li of BNL Inst. Division • 80 m x 3 cm strip • X/U stereo read-out • 384 x 2 x 2 per sensor chip (64.6 mm x 30.7 mm) • Readout chip technology choice: • SVX4 chip developed by FNAL/LBNL • 128 ch/chip • 50 m pitch read-out • Ongoing R&D • Sensor prototype tests • Tests of SVX4 readout with sensor SVX4 chip Design of the test hybrid module With SVX4 readout chip