Anatoli Romaniouk TRT Introduction TRT Introduction • TRT in ATLAS TRT in ATLAS p. 2-4 p. 2-4 • TRT design TRT design p. 5-7 p. 5-7 • TRT operation principles TRT operation principles p. 8-9 p. 8-9 • TRT electronics TRT electronics p. 10-11 p. 10-11 • TRT read-out information TRT read-out information p. 12-15 p. 12-15 • TRT test set-up TRT test set-up p. 16-18 p. 16-18 • TRT DCS tools TRT DCS tools p. 19-22 p. 19-22 • TRT DAQ graphic user interface TRT DAQ graphic user interface p. 23-24 p. 23-24 • Tasks: Tasks: a) a) Noise Characterization Noise Characterization 1
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Anatoli Romaniouk TRT Introduction TRT in ATLAS p. 2-4TRT in ATLAS p. 2-4 TRT design p. 5-7TRT design p. 5-7 TRT operation principles p. 8-9TRT operation.
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Anatoli Romaniouk
TRT IntroductionTRT Introduction
•TRT in ATLAS p. 2-4TRT in ATLAS p. 2-4•TRT design p. 5-7TRT design p. 5-7•TRT operation principles p. 8-9TRT operation principles p. 8-9•TRT electronics p. 10-11TRT electronics p. 10-11•TRT read-out information p. 12-15TRT read-out information p. 12-15•TRT test set-up p. 16-18TRT test set-up p. 16-18•TRT DCS tools p. 19-22TRT DCS tools p. 19-22•TRT DAQ graphic user interface p. 23-24TRT DAQ graphic user interface p. 23-24•Tasks:Tasks:
a)a) Noise Characterization p. 25-26Noise Characterization p. 25-26b)b) Operation with cosmic particles p. 27Operation with cosmic particles p. 27
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Anatoli Romaniouk2
Anatoli Romaniouk3
Anatoli Romaniouk
Introduction: TRT concept
Radiator
Straws
Radiator
Straws
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Anatoli Romaniouk
Straw - the main detector element
Straw design
In order to make straw rigid 4 C-fibres are attached along the straw
Reinforced straw
Straw
wall
Straw cathode – 4mm
TR optimization: the larger diameter the betterWire offset ~300 m: the larger diameter the betterSelf limited streamer length ~1 mm the larger diameter the betterMax electron drift-time the smaller diameter the better
Wire diameter – 30 m
Max electron drift-time the larger diameter the betterOperation stability the smaller diameter the better
1. Sources of the noise• Thermal noise• External pick up noise• Internal pick up noise
2. Dependence on threshold• The less threshold
• the better accuracy• the larger noise
• Particle loses ~ 1 keV in Ar-mixture• One primary ionization cluster ~ 80-100 eV (3-4 el) • Electronics noise with the detector ~3000 el• Nominal threshold should be >4 sigma above the noise (now ~14000 el)• • Phys. Threshold = El.Thr* W/(Gas gain * Signal fraction)
• In our case ~14000 el*27/5*104*0.12 = 63 eV• We are sensitive to a 1 primary ionization cluster!
• Threshold are set in DAC counts 10 DAC counts =~1400el or 6.3 eV
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Anatoli Romaniouk
Identify problematic channels and choose the operating threshold.1. Misbehaving channels
• Requirements• Analysis noise maps at different thresholds• Dead channels• Readout problem• Large noise • Too high or too low thresholds
2. Methods of the noise source identification and noise signal suppression• Signal shape.• Time distribution.• Noise rate estimate.
3. Operating threshold• What noise occupancy is allowed to be?• Noise scan
Identify detector problems, straw efficiency, tracking accuracy as a function of the electronics threshold
1. Signal from particles• Signal shape• Drift-time distribution (hit arrival time, trailing edge)• Method of timing of the signals from particles• Cosmic particle track characterization.
2. Misbehaving channels• Dead• HV problems• Straw mapping with particles
3. Straw efficiency and drift-time accuracy • Straw efficiency as a function of threshold• Drift-time accuracy as a function of threshold• Tracking at high occupancy and noise suppression
4. Basic principles of the particle Identification• Compare HL threshold distributions at different conditions• Choice of the correct representation of the results
Analysis Tool: TRTVeiwer (see test manual)
Task 2:Operation with cosmic particlesTask 2:Operation with cosmic particles