Transcript Slide 1
SVT Michael Merkin SINP MSU Tracking Specifications Summary Fwd. Tracker Angular coverage Central Tracker 5o – 40o 35o – 125o q Resolution 1 mrad 5 – 10 mrad f Resolution 1 mrad/sinq 5 mrad/sinq Luminosity 1035 cm-2 s-1 1035 cm-2 s-1 Momentum resolution (50% f-coverage (> 90% fat 5o) coverage) dp/p < 1% dp/p < 5% Performance Expectations of the Detector • SVT : Barrel + Forward • Barrel Silicon Tracker (BST): Stand Alone Tracker φ-coverage ~ 2π θ-coverage ~ [35o, ~125o] Momentum resolution ~ 50 [MeV/c] φ-resolution ~ 5 mrad θ-resolution ~ 20 mrad Tracking Efficiency >90% Performance Expectations of the Detector • Forward Silicon Tracker (FST): Works with Drift Chambers φ-coverage ~ 2π θ-coverage ~ [5o, ~35o] Tracking Efficiency >90% Improve Vertex Resolution Improve φ-resolution Design Optimization Four Barrel Regions : 8, 12, 18, 24 modules Three Forward Regions : 15, 15, 15 modules • maximizes momentum resolution Radii of region 1 and region 4 • minimizes multiple scattering no overlap of modules all electronics outside active area • strip layout reduces number of masks needed • strip layout with variable angles reduces dead areas • use of previously designed readout chips (FSSR2) SVT BST SVT FST Background Studies Full Luminosity: FST Rates Summary EM 1a 1080 1b 954 2a 895 2b 872 3a 851 3b 894 Hadronic Total 3.78 3.55 3.40 3.47 3.33 3.42 1083 958 899 876 854 897 No Energy Cut EM 1a 1b 2a 2b 3a 3b 31.3 29.2 31.1 26.3 24.6 24.2 Hadronic Total 2.45 2.23 2.15 2.22 2.16 2.23 33.7 31.5 33.3 28.6 26.8 26.4 E Dep > 20 KeV All rates in MHz Background Studies Full Luminosity: Radial FST Rates 19.35 MHz 23.87 MHz 28.56 MHz 33.70 MHz y = 19.029 mm Layer 1a Background Studies Rate (MHz) Full Luminosity: Radial FST Rates mm Transverse distance from beamline Background Dose, Fluence Studies BST Layer GeV/s 1a 1b 2a 2b 3a 3b 4a 4b 7147.8 3889.4 4578.2 3551.7 3828.5 3295.7 3145.5 2743.3 GeV/(s cm2) mrads/s 19.05 10.37 4.06 3.15 1.51 1.30 0.93 0.81 4.39 2.38 0.93 0.72 0.34 0.29 0.21 0.18 mrads/(s cm2) rad/year 0.011708 0.006371 0.000833 0.000646 0.000137 0.000118 6.360e-05 5.547e-05 1 year = 31,536,000 s 138480 75352 29566 22936 10988 9459 6771 5905 rad/(year cm2) 369.24 200.92 26.27 20.38 4.34 3.73 2.00 1.74 Background Dose, Fluence Studies BST – No Field Layer TeV/s 1a 1b 2a 2b 3a 3b 4a 4b 9375.3 3013.5 2793.4 1336.4 1566.2 875.9 1021.0 593.9 TeV/(s cm2) mrads/s 24.998 8.035 2.482 1.187 0.618 0.346 0.302 0.179 5759.6 1851.3 572.0 273.6 142.5 79.7 69.6 40.5 mrads/(s cm2) krad/year krad/(year cm2) 15.357 4.936 0.508 0.243 0.056 0.031 0.020 0.012 1 year = 31,536,000 s 181630 58381 18039 8630 4495 2514 2197 278 484.31 155.67 16.03 7.66 1.77 0.99 0.65 0.37 Background Dose, Fluence Studies FST Layer GeV/s 1a 1b 2a 2b 3a 3b 3933 3370 3288 3102 3123 3094 GeV/(s cm2) mrads/s 3.56 3.05 2.98 2.81 2.83 2.81 0.85 0.73 0.71 0.67 0.68 0.68 mrads/(s cm2) rad/year 0.77 0.66 0.65 0.61 0.61 0.61 1 year = 31,536,000 s 27042 23166 22609 21325 21463 21269 rad/(year cm2) 24.5 21.0 20.5 19.3 19.6 19.3 Background Dose, Fluence Studies FST – No Field Layer TeV/s 1a 1b 2a 2b 3a 3b 52.92 43.45 39.82 35.18 32.88 28.06 GeV/(s cm2) mrads/s 48.00 39.41 36.12 31.91 29.83 25.45 11.53 9.47 8.68 7.66 7.16 6.11 mrads/(s cm2) kilorad/year 10.46 8.59 7.87 6.95 6.50 5.54 1 year = 31,536,000 s 363.8 298.7 273.7 241.8 226.0 192.9 rad/(year cm2) 329.9 270.9 248.3 219.3 205.0 175.0 SVT Cooling (FSSR2 ASIC) Summary of Sensor Specifications • Single – Sided Construction Lower cost – higher production yields with less defects • High resistivity (~5kΩ/cm) n-type bulk Sensor can be fully depleted at relatively low voltage • <100> Surface Orientation Reduces sensor surface damage due to radiation • Al strips AC coupled to p+ strip implant strips Protect readout ASIC from DC strip currents • Surface Passivation To protect the semiconductor surface from electrical and chemical contaminants • Summary of Sensor Overhang ofSpecifications AL strips (6 µm) over p+ implants Improves HV stability of the sensor • Bias Voltage to strips via Polysilicon Resistors Decouples individual biased AL strips, best radiation performance • Guard Ring Shapes the electric field at the border of the active area • Outer n++ Protecting Ring Defines the volume, prevents high field at the sensor’s edge • Low Leakage Current Reduces noise BST Sensor Cross Section Hartmann, Frank. Evolution of Silicon Sensor Technology in Particle Physics. Springer Berlin / Heidelberg, 2009. Sensor Specifications Mechanical Layout Summary Outer Size 42.000 x 111.625 mm Active Area 40.032 x 109.955 mm Dicing Tolerance ± 20µm # of readout strips 256 # of intermediate strips 256 Implant strip pitch 78 µm Readout strip pitch 156 µm Implant strip width 20 µm Aluminum strip width 26 µm Implant width / pitch ratio .256 Angle of strips 0°(strip 1) to 3°(strip 256) Sensor Specifications Summary of Electrical Properties Full depletion voltage 40<V<100 (25°C@<45%RH) Interstrip capacitance <1.2 pf/cm Leakage current (@ depletion V) <1nA/cm2 Strip to back side capacitance <0.2 pF/cm Interstrip isolation (@150V) >1 GΩ Resistance of Al strips < 20 ohm/cm Coupling capacitance >10 pf/cm Total (strip) capacitance (Ctot = Cint + Cback at 1 MHz) ≤1.3 pf/cm Value of poly-silicon bias resistor 1.5 MΩ Single strip DC current < 3 nA BST Hybrid Sensor Layout BST Module Sensor Layout Thanks! Backup Sensor Testing Tests by vendor for each sensor: • Sensor Leakage Current • Interstrip, backplane, and total capacitance • Depletion voltage • Interstrip resistance, Poly bias resistors, Al Strip resistance Information to be supplied by the vendor for each sensor: • ID # engraved in the area provided on the sensor • For each wafer, list the sensor ID numbers • Test results for each sensor • Traceability data of processing (batch relative yield, start and end date, and wafer numbers FSSR2 - Specifications • High density – 128 channels / chip • Low Power – 3 mW / channel • Data driven architecture – no trigger (synchronized with DAq with timestamp clock) • Zero suppressed data readout • Fast output – 840 Mbit/sec readout capability (1-6 programmable serial outputs) FSSR2 - Validation • Current Test Plan consists of 95 tests exercising all aspects of the ASIC to verify specifications • Test Board created to inject external charge and connect chip to sensor • Document results to aid in collaboration with other facilities • Tests with 1st article SVT modules scheduled for 2010 • CLAS-Notes Radiation Length of Module Components Material Silicon Epoxy GFRP Rohacell 71 GFRP Epoxy Silicon Total Radiation Thickness Thickness Length [X0] [mm] [%X0] [mm] 93.700 0.300 0.320 443.700 0.025 0.007 250.000 0.250 0.100 450.000 2.000 0.040 250.000 0.250 0.100 443.700 0.025 0.007 93.700 0.300 0.320 3.150 0.894 ASIC Survey Chip SVX4 FSSR2 AToM Beetle FPIX2 FEI3 Readout Type Digital (8-bit) Digital (3-bit) Digital (4-bit) Analog/ Binary Digital (3-bit) Digital (5-bit) Project D0 & CDF BTeV BaBar LHCb BTeV (pixel) ATLAS (pixel) Notes Primary option R&D Out of production Under revision Material budget Material budget • Options: SVX4, FSSR2 Comparison of ASICs Parameter FSSR2 SVX4 Designed for BTeV CDF/D0 Engineering run Used in experiment Yes Yes No CDF/D0 Channel/chip 128 128 pipeline/needs external trigger Data architecture self trigger and time stamp 105 MByte/s, Readout rate 1- 6 programmable serial outputs ADC type 3 bit flash 56 MBytes/s 8 bit Wilkinson FSSR2 tests Signal= 20000eWorst case S/N=>10 Signal rate distributions for the laser and injected signal Signal= 20000e- Sensor overview 2 Dummy Strips Guard rings and Bias Line Scratch Pads Corner Pad Corner pad and Scratch Pads PolySilicon Resistors