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L.Kurchaninov. MPI HEC Group 14 Apr 200 5. Outcome of the HEC standard Tests. Or “What I expect from Pavol’s Analysis”. Set of measurements Analysis of pedestals Noise at channel level Noise at segment level Noise at module and higher levels Noise frequency analysis
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L.Kurchaninov MPI HEC Group 14 Apr 2005 Outcome of the HEC standard Tests Or “What I expect from Pavol’s Analysis” • Set of measurements • Analysis of pedestals • Noise at channel level • Noise at segment level • Noise at module and higher levels • Noise frequency analysis • Signals and xtalk analysis • Test outcome
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Set of Measurements • Standard sequence as in assembling tests done for each half-quadrant : • Cable check • Short run with on-line analysis • Noise with calibration board disabled, 32 samples • Std run with DAC ramp, 1 ns delay step, 5 patterns, 16 samples • Xtalk with one generator ON • Extended analysis to study in detail: • Thermal noise and excess noise • Spread of signal parameters • Bad channels • Outcome of the tests (see last slide) • Signal quality and noise quality for each channel (to be defined) to DB • Summary to EDMS
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Some Definitions PED: pedestal, either constant or a function of event number NSC: noise (=ADC-PED) for each event, each channel, each sample NSS: noise for segment = sum(NSC) over channels NSG: sum(NSC) for pre-defined group of channels, e.g. FEB, half-FEB, etc. NMC: mean(NSC) over samples for each event, each channel NMS: mean(NSS) over samples for each event, each segment NMG: mean(NSG) over samples for each event, each group of channels D[X]: dispersion of random X. RMS[X]=sqrt(D[X]) K[X1,X2]: correlation between random values X1 and X2 Excess noise factors for group of channels: FSG = D[sum(NSC)]/sum(D[NSC]) FMG = D[sum(NMC)]/sum(D[NMC])
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Analysis of Pedestals • It is known that FADCs have significant pedestal drift • NMS vs. event number. Drift is different in different runs • Define PED either fitting with a reasonable function or cut to stable area. All analysis so far done for N>10k • Some channels are still not stable in N>10k • Run3 done with 10k events (will be) done with special PED definition • Long-term (inter-event) correlation of NMC (NMS) to see quality of cut (or fit) and possible low frequency instabilities no correlations observed
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Noise at Channel Level • RMS[NSC] for one of samples or averaged over all samples. This is the basic reference for noise performance DONE (except of run 3). Characterize channels, identify noisy channels to be done • Non-gaussian noise is not seen at channel level • Geometrical correlations of NMC calculated within segments DONE. Coherent noise seen for some segments. Study problematic areas
L.Kurchaninov Outcome of the HEC Standard Test NSS NMS MPI HEC Group 14 Apr 2005 Noise at Segment Level • RMS[NSS] for one sample or mean over samples. This is a reference for segment. DONE. Compare segments, identify noisy areas. • RMS[NMS]. This is a study of non-gaussian noise. DONE. Compare segments. Define gauss and sin components, compare with data from previous step • Noise excess factor is another way to characterize coherent noise. For each segment: FSS and FMS. Compare with data from previous steps.
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Noise at Module and Higher Levels • Correlations between segments of the same module DONE. Compare with excess noise factors and non-gaussian contributions • Half-Q level: f-correlation z-correlations, … This is a further step to characterize global noise performance
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Noise Frequency Analysis • For noisy segments: define frequency of sin component from correlation amplitude-derivative, like Sasha Savin made for TB data DONE. In all noisy segments ellipsoid is not seen. Frequency is lower than 40-50 KHz
L.Kurchaninov Outcome of the HEC Standard Test Q4 FEB 3 ch 34: no GND of Q-cable Some distortion MPI HEC Group 14 Apr 2005 Signals and Xtalk analysis • Compare signals with reference to identify weak channels or calibration lines • No theoretical reference due to non-ATLAS readout. Reference could be mean over 8 runs… or specially adjusted model • Waveforms for bad and weak channels, diagnostics if possible. Cross-reference with TDR measurements • Xtalk matrix per segment, as in (some) cold tests. Values in %, no shape analysis (not of the first priority)
L.Kurchaninov Outcome of the HEC Standard Test MPI HEC Group 14 Apr 2005 Test Outcome • Documents in EDMS Test description Channel characteristics Bad signal and calibration channels Noise performance • To production DB: Table of channel parameters <ampli(gain), time, signal quality, RMS>