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GEM Tracker for high luminosity experiments at JLab Hall A.
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GEM Tracker for high luminosity experiments at JLab Hall A Evaristo Cisbani (8),V. Bellini (5), M. Capogni (2), S. Colilli (8), R. De Leo (4), R. De Oliveira (1), V. De Smet (3,5), R. Fratoni (8), S. Frullani (8), F. Giuliani (8), M. Gricia (8), F. Librizzi (5), M. Lucentini (8), F. Mammoliti (5), S. Minutoli (6), P. Musico (6), F. Noto (5), R. Perrino (7), F. Santavenere (8), C. Sutera (1) CERN, Geneva, Swiss (2) ENEA Casaccia, Italy (3) Haute Ecole Paul Henri Spaak, ISIB-Brussels, Belgium (4) INFN Bari and University of Bari, Bari, Italy (5) INFN Catania and Catania University, Catania, Italy(6) INFN Genova, Genova, Italy (7) INFN Lecce, Lecce, Italy (8) INFN Roma Sanità group and Italian National Institute of Health, Rome, Italy E. Cisbani et al. – GEM Tracker @ JLab Hall A
add Hall D (and beam line) Upgrade magnets and power supplies CHL-2 Energy Upgrade of CEBAF accelerator @ JLab 6 GeV CEBAF (< 2013) Max Current: 200 mA Max Energy: 0.8 - 5.7 GeV Long. Polarization: 75-85% E. Cisbani et al. – GEM Tracker @ JLab Hall A 12 GeV CEBAF (>2013) $ 310M Max Current: 90 mA Max Energy Hall A,B,C: 10.9 GeV Max Energy Hall D: 12 GeV Long. Polarization: 75-85%
Experimental Halls Today E. Cisbani et al. – GEM Tracker @ JLab Hall A
Experimental Halls after 2013 E. Cisbani et al. – GEM Tracker @ JLab Hall A
Origin of quark and gluon confinement (non-perturbative QCD) Gluonicexcitations, existence and properties of exotic mesons (and baryons) Mesons and baryons spectroscopy Dynamics of the quarks/gluons in the nucleons Parton Distributions Functions (and Fragmentation Functions) New view of nucleon structure via the Generalized Parton Distributions (GPDs) accessed in Exclusive Reactions Form Factors at high Q2, improve knowledge of charge and current in the nucleons– constraints on the GPDs Dynamics of the nucleons in the nuclei The Quark Structure of Nuclei (resolving the EMC effect) The Short-Range Behavior of the N-N Interaction and Its QCD Basis Quark propagation through Nuclear Matter (hadronization) Standard model limits High Precision Tests of the Standard Model via Parity-Violating Electron Scattering Experiments (low energy but very high luminosity) JLab physics investigations E. Cisbani et al. – GEM Tracker @ JLab Hall A
Some challenging experiments in Hall A Mostdemanding E. Cisbani et al. – GEM Tracker @ JLab Hall A High Rates Down to ~ 70 mm spatial resolution Large Area Maximum reusability: same trackers in different experimental configuration
SuperBigbite Spectrometer in Hall A High photon up to 250 MHz/cm2 and electron 160 kHz/cm2 background E. Cisbani et al. – GEM Tracker @ JLab Hall A Use VME64x • Electronics for: • Front GEM tracker • Large backward GEM trackers • >100k channels • Large luminosity • Moderate acceptance • Forward angles • Reconfigurable detectors
Tracker approach: 40x50 cm2 Module • Use the same “basic” module for all trackers types • Size: 40x50 cm2 active area + 8 mm frame width • FEM study: • 3 x GEM foils (moving to single mask tech.) • 2D strip readout (a la COMPASS) - 0.4 mm pitch • x/y coordinates E. Cisbani et al. – GEM Tracker @ JLab Hall A • Two exceptions in readout foil: • Front Tracker last 2 chambers: • Double segmented readout to reduce occupancy (Pentchev talk) • Coordinate Detector: • 1D strip readout • 1 mm pitch
Front Tracker Geometry X(4+4) Back Trackers Geometry Tracker Chambers configuration GEp(5) SBS x6 • Modules are composed to form larger chambers with different sizes • Electronics along the borders and behind the frame (at 90°) – cyan and blue in drawing • Carbon fiber support frame around the chamber (cyan in drawing); dedicated to each chamber configuration E. Cisbani et al. – GEM Tracker @ JLab Hall A
Drfit, GEM and Readout foils HV Terminals Reference holes 20 HV sectors on one side of the GEM Gas In/Out E. Cisbani et al. – GEM Tracker @ JLab Hall A ZIF terminals (0.3 mm pitch) Protection resistors on each HV sectors
Gas Flow / COMSOL MultiPhysics Simulation Final design E. Cisbani et al. – GEM Tracker @ JLab Hall A COMSOL/Thin-Film Flow Model Maximize uniformity and steady flux Minimize spacer apertures V. De Smet + F. Noto
MonteCarlo + Digitazation + Tracking • Highg+ e background hits • MHz/cm2 • (Signal is red) 6 GEM chambers with x/y readout Use multisamples (signal shape) for background filtering Bogdan Wojtsekhowski + Ole Hansen + Vahe Mamyan et al. E. Cisbani et al. – GEM Tracker @ JLab Hall A
2D Readout Electronics Components 8 mm Up to 10m twisted, shielded copper cable (HDMI) 49.5 mm 75 mm Passive backplane (optional) E. Cisbani et al. – GEM Tracker @ JLab Hall A • Main features: • Use analog readout APV25 chips • 2 “active” components: Front-End card and VME64x custom module • Copper cables between front-end and VME • Optional backplane (user designed) acting as signal bus, electrical shielding, GND distributor and mechanical support GEMFECMPD DAQ
Front End Card (Proto 1 – basically final) Panasonic FPC connectors Analog driver (not used) Voltage regulator Thermometer 2 In/Out options APV25 bonding on PCB APV25 Input Protection diodes Analog Output mainly for test Digital Input + Power supply ERNI marketing changed: female connector available only wired E. Cisbani et al. – GEM Tracker @ JLab Hall A Analog out + Digital Input + Power supply Improved ZIF connectors (2x77) and grounding in the final version GEM FECMPD DAQ
Radiation Hardness Test of Voltage Regulators Irradiated by 137Cs (0.834 Gy/min) for 3 days -> corresponding to about 4.5 JLab years of operation Comparison of Rad. Hard LHC 4913 PDU and Standard SMD TPS736 Voltage Regulators Power Cycle E. Cisbani et al. – GEM Tracker @ JLab Hall A
MultiPurposeDigitizer v1 Flash EPROM Thermometer Optical Fiber Oscillators (100 MHz, 62.5 MHz) USB ETH Live Insertion Hot-Swap 2x64Mbyte SDRAM Voltage Regulators Digital OUT (HDMI) E. Cisbani et al. – GEM Tracker @ JLab Hall A ADCs 50 MHz 12 bits 16 Analog IN (HDMI) Analog Receivers • VME64x controller hosts the digitization of the analog signals coming from the front-end card. • It handles all control signals required by the front end cards (up to 16 FE) • Compliant to the JLab/12 VME64x VITA 41 (VXS) standard • We intend to make it accessible by standard VME/32 as well • 2 HDMI-type A: digital lines + 2 analog lines (compatible with RD51/SRS hybrids connector) • 2 HDMI-type B: 16 analog lines • Added delay line for clock-convert phase fine tuning (DELAY25 from CERN)
Electronics layout on one chamber E. Cisbani et al. – GEM Tracker @ JLab Hall A FE cards are connected by a passive backplane (with hard rad voltage regulators); backplane acts as a good GND connection for the cards Front-end cards are electromagnetically shielded by backplane and external frame (with thin conductive tape)
External Service Frame • Mechanical support of: • GEM module • Electronics • Services (Gas, Cabling ...) E. Cisbani et al. – GEM Tracker @ JLab Hall A
Assembling the first 40x50 cm2 module Stretching Stretcher design from LNF / Bencivenni et al. Use stretching and spacers to keep foil flat E. Cisbani et al. – GEM Tracker @ JLab Hall A Foil Tension: T = 2 kg/cm Spacer Sector: S = 170 cm2 Expected maximum pressure on foil P 10 N/m2 Maximum foil deformation: u 0.0074 * P * S / T = 6.4 mm Gluing the next frame with spacers
Beam test @ DESY (EUDET support) E. Cisbani et al. – GEM Tracker @ JLab Hall A
Beam test @ DESY (EUDET support) • Fully equiped GEM module • 18 front-end cards • 2304 channels • (front end cards on the other side) • 7 independente HV levels E. Cisbani et al. – GEM Tracker @ JLab Hall A 2-6 GeV low intensity electron beam / silicon tracker available Data taking: end of 2010
Beam test @ DESY (EUDET support) July/2010 (10x10 cm2 GEM) Dec/2010 On-line data: beam profile E. Cisbani et al. – GEM Tracker @ JLab Hall A Large improvement from July/2010
Single Events @ DESY 2010 Test Clear hits But still noisy events x y E. Cisbani et al. – GEM Tracker @ JLab Hall A Electronics Firmware were not fully reliable (several misaligned events and channels) which makes the analysis quite difficult.
CERN test (magnetic field effects) E. Cisbani et al. – GEM Tracker @ JLab Hall A Electronics firmware consolidated but No chance to take good data: lost the 40x50 prototype (GEM 2 short) due (likely) to improper operation of the HV system.
Magnetic field / Extrapolation from KLOE Data Limit due to readout pitch E. Cisbani et al. – GEM Tracker @ JLab Hall A Expected fringe field at JLab
10x10 GEM Tracker for High Intensity Test E. Cisbani et al. – GEM Tracker @ JLab Hall A
Electronics (2500 channels) @ Olympus GEM Olympus experiment (at DESY) aims to measure the higher order effects in elastic electron – proton scattering which could explain the Form Factor measurements discrepancy. The APV electronics has been installed on the Olympus GEM tracker made of 6 10x10 chambers with 2D readout (pad/strip) E. Cisbani et al. – GEM Tracker @ JLab Hall A Commissioning summer/fall 2011; data taking in 2012
Several improvements in the last 6 months: Bugs fixed (in electronics firmware mainly) Mechanics and GEM design improved Montecarlo and Track Reconstruction Firmware largely improved Design of the JLab GEM Tracker is finalized Work is still in progress in several directions: External service frame under finalization Readout electronics firmware (move to external SDRAM) DAQ Software Data analysis HV system - independent channels with current monitor (LNF/Corradi) New production of 40x50 module just requested (mechanics and foils); clean room ready; stretcher under revision Final electronics production will start in second half of September Conclusions E. Cisbani et al. – GEM Tracker @ JLab Hall A