The CMS Silicon Strip Tracker and its Electronic Readout Markus Friedl Dissertation May 2001
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 2 Introduction LHC Large Hadron Collider: future high energy physics accelerator at CERN (starts 2006) CMS LHC LHC-B ATLAS LHC-B electrons positrons protons antiprotons Pb ions Aim Measure new particles and their properties to verify the Standard Model (e.g. Higgs)
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 3 Introduction CMS Compact Muon Solenoid: One of four collision detectors at LHC Tracker Silicon strip and pixel detectors (206m 2 ) 384 scientists from 42 institutes participate Austria Insistute of High Energy Physics (HEPHY) Austrian Academy of Sciences Nikolsdorfergasse 18 A-1050 Vienna
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 4 Thesis Contents LHC/CMS Silicon detectors CMS Silicon Tracker Introduction to future particle accelerator and collider experiment at CERN General principle and readout amplifiers including detector model and simulations (published in Nucl. Instr. Meth. A461 (2001) 192-196) Details about configuration and readout electronics My research Construction and tests of detector modules. and readout components Irradiation of detectors and electronics. Analog optical link evaluation Magnetic field tests ADC frequency response measurements
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 5 Silicon Detector Module Tests CMS Silicon Tracker Prototype detector module with three APV25 front-end readout chips (HEPHY Vienna) Tests Characterized in particle beam together with other modules
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 6 System Overview HEPHY setup Complete APV readout hardware Cooling box for detector operation at 10 C VME-based back-end system PC-controlled data acquisition Scintillator/PM Power PM Signal Clock Trigger Logic Clock/Hold Distr. NIM Clock/Trigger/Reset APV Sequencer IC 2 VME-I 2 C VME Analog Data VME-ADC PC Detector Modules inside Cooling Box Repeaters Distribution Board Bias HV HV Supply Components shown in red are self-made
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 7 System Overview Software Powerful control and readout system (self-made) Screenshot Slow Control Data acquisition software displaying Landau signal distribution (online analysis) Second PC for temperature and HV control/monitoring
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 8 Pictures Before installation at Paul Scherrer Institute (PSI) near Zurich
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 9 After installation in control room
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 10 Fully equipped cooling box in beam area
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 11 Bias Voltage Scan Selected data from beam tests 25 HV Scan Deconvolution Mode, Standard settings, 350MeV/c pions 20 APV25 MP SNR 15 10 APV6 5 0 0 0.5 1 1.5 2 2.5 3 Bias Voltage/Depletion Voltage APV25S0 - PD25-1 sensor APV25S0 - V25-2 6'' sensors APV25S1 - PD26-2 sensors APV25S1 - PD27-2 sensors - irradiated APV6 - PD3-2 sensors APV6 - PD4-2 sensors - irradiated Simulation - APV25-2 sensors APV25 SNR 17 for non-irradiated full-size module at CMS operating conditions SNR>10 is required for 100% efficiency sufficient margin for irradiation degradation APV25 outperforms previous APV6 version
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 12 High Intensity Beam 24 hours of LHC beam rate (1 MHz cm -2 corresponds to CMS r=12 cm) Silicon detector Linear current increase, α 8 10-17 A cm -1 Agrees with CERN RD48 (ROSE) collaboration measurements Detector/APV25 performance unchanged Vienna APV25 detector currents during high beam intensity Cooling failure Reduced intensity Beam induced current High intensity on High intensity off
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 13 Electronics Irradiation Why? Where? What? CMS front-end electronics must withstand hostile radiation environment High intensity pion beam at Paul Scherrer Institute (PSI) near Zurich 8 APV25 CMS front-end readout chips produced in 0.25µm CMOS
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 14 Radiation Effects Effect Scope Damaging Observed w/apv25 Single Event Upset (SEU) digital analog no no yes yes Single Event Latchup (SEL) digital yes no SEU SEU in digital logic Local charge deposition by highly ionizing particle (e.g. recoil atom) Memory cell (flip-flop) changes state when enough charge is deposited on sensitive nodes (1 or 2) State machine is disturbed until reset
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 15 Digital SEU Results More than 3000 SEUs on all 8 APVs Cross section Number of upsets divided by fluence Measured: σ = 2.25 10-12 cm 2 (slightly depending on temperature) Agrees with prediction from similar test with heavy ions Extrapolation to CMS: Section Average Flux [cm -2 s -1 ] Number of APVs Mean SEU time [s] SEUs/time [h -1 ] Inner Barrel 1.40E+06 14400 22.1 162.7 Outer Barrel 4.85E+05 29232 31.4 114.7 Periodic reset required to reactivate chips whick are stuck after SEU
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 16 Cross-Section and Sensitive Area Comparison between chip areas and SEU cross-sections of different logic blocks Sensitive area and cross-section 2.0E-04 2.0E-12 1.8E-04 1.8E-12 1.6E-04 1.6E-12 2 Area A [cm ] 1.4E-04 1.2E-04 1.0E-04 8.0E-05 6.0E-05 Sensitive area Cross-section 1.4E-12 1.2E-12 1.0E-12 8.0E-13 6.0E-13 2 Cross-section σ [cm ] 4.0E-05 4.0E-13 2.0E-05 2.0E-13 0.0E+00 PIPE+CONTR FIFO I 2 C 0.0E+00 Principal agreement Exact cross-section depends on electrical and geometrical circuit layout
M. Friedl The CMS Silicon Strip Tracker and its Electronic Readout 17 Summary CMS @ LHC Future high energy detector experiment / accelerator at CERN Electronics Full APV readout system developed at HEPHY Important contributions to the CMS Silicon Tracker R&D: Silicon Detector Radiation effects Prototype modules were assembled and successfully tested in particle beams Excellent SNR obtained Detectors: Linear current increase observed Electronics: Single Event Upset cross section measured Many more results within my thesis Web http://cern.ch/friedl Dissertation