Transcript Pernegger-BCM0504.ppt

Diamond Beam Conditions Monitor for ATLAS
(H. Pernegger, CERN)
H. Pernegger, CERN, RD42 coll. Meeting May 2004
People involved sofar from ATLAS Inner Detector
 JSI, Ljubljana
 G. Kramberger, I. Mandić, M. Zavrtanik, V. Cindro, M. Mikuz
 CERN
 H. Pernegger
 Fotec, Wiener Neustadt
 E. Griesmayer, H. Frais-Kölbl
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Part of the ATLAS Radiation Monitoring System
 Instantaneous
 Beam Condition Monitor – BCM
Draft EDMS document ATL-IC-ES-0012
 Integrating – on-line
 Total Ionization Dose - TID
 Non-Ionizing Energy Loss – NIEL
 Thermal Neutrons
EDMS document in preparation
 Integrating – off-line
 TLD – not discussed today
H. Pernegger, CERN, RD42 coll. Meeting May 2004
ATLAS BCM goal
 Goal of the BCM detector system inside the ATLAS Inner Detector
 Monitor normal operation conditions
 Measure rate of collision
 Measure background rate close to vertex
 Protection
 Detect early signs of beam instabilities
 Issue warning and alarm signals for equipment protect
 Input to ATLAS Detector Safety system and LHC beam abort
H. Pernegger, CERN, RD42 coll. Meeting May 2004
ATLAS BCM - beam loss scenarios
Simulations of beam orbits with wrong magnet settings (D. Bogdan)
exhibit scenarios with beam scrapping TAS
Time constants of D1 & D2 dipoles large
 Can abort beam if detected early
H. Pernegger, CERN, RD42 coll. Meeting May 2004
ATLAS BCM during normal running
 Time-Of-Flight measurement to distinguish collisions from back
ground
12ns
Time difference
Need to measure single MIPs fast!
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Timing of Hits on Collimators
2x4 detector stations, symmetric in z
TAS events: Δt = 2z/c
Interactions: Δt = 0, 25, … ns
H. Pernegger, CERN, RD42 coll. Meeting May 2004
CMS simulations of 7 TeV p on TAS
From M. Huhtinen
Zoom on ID
~ MIPs/cm2 per proton
(ATLAS simulations by M Schupe in progress)
H. Pernegger, CERN, RD42 coll. Meeting May 2004
ATLAS BCM requirements
 Distinguish TAS events from interaction events
 Installation at Dt = 12.5 ns -› Dz = 3.75 m
 Rise-time < 1 ns
 Pulse-width < 3 ns
 Base-line restoration < 10 ns
 Single MIP sensitivity
 S/N for MIP’s 10:1 before irradiation
H. Pernegger, CERN, RD42 coll. Meeting May 2004
BCM installation in ATLAS Pixel Support
Pixel support tube: mid crucifix at z = 1838 mm, r > 100 mm
Detectors to be mounted at 45 degrees
BCM mounting points
Cables: 4 mm coax up to PP1, 8 mm to USA15
HV, LV: custom Kapton insulated shielded TP
Routing through single pixel phi sector/side
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Detector
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90Sr
source test at CERN
Diamond detector
w =470 µm, CCD ~ 200 µm
HV Bias 1000 V
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Different versions of FE electronics from Fotec
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500Mhz (40 dB) (2 stages)
1 Ghz (60 dB) (3 stages)
LeCroy 1 GHz scope
90Sr
source
Pb collimator
Diamond on support
Scintillator
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Readout for characterization with fast current amplifier
 Based on LabView
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Diamond + electronics Tests in Testbeam
 MIP signal (testbeam & Sr90 source)
 after 16m of cable
 perpendicular to beam, double diamond assembly
 Rise time 900ps, FWHM = 2.1ns
SNR = 7.3:1
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Preliminary Detector & Electronics Tests: Sr90
 MIP signal in CDS
113
 Perpendicular
 Tested with
source in Lab
 Results:
 “ENC” = 1400 e SNR = 5.4:1
H. Pernegger, CERN, RD42 coll. Meeting May 2004
Amplifier radiation test in Ljubljana
Tested 1 stage of 1 GHz amplifier (20dB)
( test of 500MHz just started)
Bi-polar InGaP transistor
Irradiated to Φeq = 1, 5, 10 x 1014 n/cm2 in reactor
Verdict:
Amplifier still usable
after 1015 n/cm2
H. Pernegger, CERN, RD42 coll. Meeting May 2004
BCM Logic Scheme
ADC-> Intensity
Warning/Alarms
TDC->TOF
H. Pernegger, CERN, RD42 coll. Meeting May 2004
ATLAS BCM Next steps
 Finalizing design of FE-end part
 Continue with diamonds back-to-back assembly & amplifier
irradiation
 Finalize required diamond material parameters
 Optimize amplifier design (S/N 10:1)
 Started to look at Integration aspects
 Mounting of detector + FE electronics
 Design of readout logic
H. Pernegger, CERN, RD42 coll. Meeting May 2004