Outcome of the HEC standard Tests

1. 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

2. 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

3. 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])

4. 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

5. 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

6. 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.

7. 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

8. 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

9. 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)

10. 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>