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Nikhef Annual Meeting 13 Dec 2001 Future Vertexing. Els Koffeman for Nikhef Vertex Group. Topics. No report on Zeus, Hermes, Alice, LHC-B, Atlas in spite of much progress No report on beautiful infrastructure R&D vertex detectors Very High Luminosity Hadron Colliders
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Nikhef Annual Meeting13 Dec 2001Future Vertexing Els Koffeman for Nikhef Vertex Group
Topics • No report on Zeus, Hermes, Alice, LHC-B, Atlas in spite of much progress • No report on beautiful infrastructure • R&D vertex detectors • Very High Luminosity Hadron Colliders • Extreme radiation hardness (1x 1016 /cm-2) • Linear Colliders • High precision (1-5 micron point resolution) • Low material (0.1 X0 per layer) • ‘small’ detectors • Medipix • Time Projection Chamber els koffeman
Electronic Department • Recent projects • Alice: analoge buffer/line driver, digital control ic (jtag + glue logic), power supply is prevented for single event latchup • LHCB: analog line driver en comparators voor beetle chip • pixel: 4 bits adc per pixel • zeus: fail safe token voor helix • general: low noise amplifier • Four FTE engineers working on VLSI • Education • EPFL (Lausanne) • Advanced Analog IC Design (5 people) • Advanced Digital IC Design (3 people) • Practical Aspects in Analog & Mixed Mode ICs (3 people) • Transistor-level Analog IC Design (2 people) • expected: low voltage analog IC (2 people) els koffeman
Quick Reminder N P • Silicon as a sensor • 300 micron thick wafer • High resistivity, purity • Surface strips, pixels, pads • Silicon as readout • Poor quality wafer • Photolitography makes Integrated Circuits • All structure contained in few micron thickness • Most important component is transistor • Current technology ‘CMOS 0.25 micron’ Silicon pixel,pad,strip contact gate P els koffeman
Signal! els koffeman
Crystal Damage ! (vacancy, interstitials) Leakage currents Need High Voltage Less collected charge Charge generation Inside CMOS! Transistor performance degrades Chip ‘blows up’ els koffeman
R&D vertexing • CERN • RD 19 Pixels • RD 39 Cryogenic operation of silicon • RD 42 Diamond detectors • RD 48 ROSE radhard silicon • RD 49 Radhard Electronics • Proposal for new R&D group • LCFI (linear collider flavour identification) • CCD detector for TESLA • 8 UK institutes, CERN, SLAC • MIMOSA • Monolithic pixels • Proposal submitted to DESY PRC • Strassbourg, Geneve, Nikhef, Liverpool, Glasgow, RAL, … els koffeman
Radiation Hardness of Silicon • The leakage current damage parameter is material independent • Radiation damage very different for different particles (expressed in hardness factor K) • 24 GeV protons K =1 • Slow neutrons K=0.9 • Fast neutrons K=1.7 • Gamma 60-Co K=2x10-6 • ‘Effective doping changes’ (or increasing depletion voltage) improved by oxygenation of the material • A macroscopic damage parameter model has been developed which can be used to predict detector parameters in a given radiation environment including annealing effects els koffeman
Radiation harder with oxygen? • Two methods were found to highly oxygenate silicon. • Firstly, at the ingot growing stage. • Secondly by diffusion of oxygen into ANY wafer using a high temperature drive-in • Technology has been successfully transferred to several silicon detector manufacturers (SINTEF,Micron, ST, CIS) and full-scale microstrip detectors have been produced. els koffeman
Pixel systems • MCM multi chip module • ‘traditional’ 300 um thick pixel sensor bump bonded to a chips with amplifiers and readout. • CCD • Charge collection in thin surface layer • charge transferred through the wafer • Monolithic pixel • use standard CMOS wafer • simple readout per pixel chip sensor Surface sensor sensor els koffeman
Monolithic Pixels • No depletion layer • charge diffusion only • < 1000 electrons • cell = • Monolithic:part of the CMOS is used as detector element • Will it work ? els koffeman
MIMOSA - I 4000 pixels ! 1.2 x 1.2 mm2 els koffeman
MIMOSA Signal / noise = 40 Efficiency = 99% Resolution NIKHEF proposed a ladder ‘concept’ thickness 0.05 mm 12 cm long 3 x 2 cm wide 0.9 g silicon 0.8 g support els koffeman
Diamond – Pixel detector els koffeman
Medipix- recent developments • Chip Design (0.25 mm) (TMR EU project) • DAC's for Alice/LHCb chip (radhard) • DAC's for Medipix2 chip • MUROS2 Interface for Medipix2 • Multi-Chip Board for 2x4 multichip Medipix2 imager • Dynamical Defectoscopy • micro-crack development in Aluminium (Marie Curie EU project) els koffeman
Multi-Chip Board Vbias PC+DIO Chipboard MUROS2 10 Mhz SCSI-5 Cable 160 Mhz LVDS 8 ASIC chips Medipix2 chip size 14 x 16 mm2 1 Sensor 28 x 56 mm2 (fully sensitive area) 512 x 1024 Pixels of 55 x 55 mm2 (0.5 Megapixel) Prototype, useful for e.g. Small Animal Imaging els koffeman
3 different micro ADC's David San Segundo Bello <100 x 100 mm area <1 mW power els koffeman
Chipboard Top layer metal High Density Interconnect Technology 9 metal layers (5 in kapton build-up) 1840 staggered m-via's 366 drilled-through via's 80 SMT capacitors els koffeman
X-ray Defectoscopy 1mm Hole 7 Si GaAs Si + FlatField Correction 5 mm 0.5 mm els koffeman
TPC for a linear collider • Traditional TPC: signal collected on wires • Principle of GEM introduced by Sauli • Used in conjunction with MSGC’s or plain electrodes • New idea: get the electrons directly in a chip! (Harry v.d Graaf, Jan Visschers, Erik Heijne) • If successful (with 60 *60 micron pitch) • Resolution limited by diffusion • Optimise gas max for this • Much better track separation • Can improve all time favorite Aleph TPC with 30-40 % els koffeman
TPC + medipix chip Medipix chip kathode Sensitive area ~ 1m ~ 1mm GEM els koffeman
TPC plans • Build proto type • If charge measured = > connect to Medipix chip. • Develop prototype for TESLA…. • Need 15 m2 of chips! els koffeman
Conclusion…. R & D • Medipix • Diamond • CMOS sensors • micro-electronics • Novel TPC R&D is in good shape we need a vertex group ! Do we need a vertex group ? els koffeman