DESY BT analysis- Systematics summary -

S. UozumiDec-5th 2011 ScECAL meeting

sources and evaluation method of systematics(based on data)

Perform pseudo-experiments and see variation• Response calibration by MIP (stat. uncertainty of calib. const)• Correction for temperature dependence (stat. uncertainty of temperature-gain correction coefficient)

Take edge-to-edge width :• Light cross-talk (on and off)• MPPC saturation correction

– MPPC gain measurement by LED system (stat error of 1 p.e. signal)– Electronics inter-calibration of low/high gain modes (uncertainty of

inter-calib factor)– Shape of saturation correction curve (effective num. of pixels)

Systematics from MIP calibrationDistribution of calib constant and its statistical uncertaintyfor all the channels of 3 configurations :

Systematics on MIP calibrationResult of 100 pseudo-experiment (RMS/RMS = 7%) :

Deviation fromLinearity

Energy resolution

Systematics on MIP calibration summary

• Effect is comparable or smaller than stat. uncertainties.

• Relatively large effect on resolution of 3rd configuration.

Systematics on temp. correction

Distribution of temp. correction factor and its statistical uncertaintyfor all the channels of 3 configurations :

Temperature (oC)C

alib

. C

onst

. (A

DC

cou

nts)

From CAN-006 :

Systematics on temp. correctionResult of 100 pseudo-experiment (RMS/RMS = 7%) :

Deviation fromLinearity

Energy resolution

Systematics on temp. correction summary

• Effect is comparable or slightly larger than stat. uncertainties.

Systematics on Light cross-talk• Compare results with cross-talk correction turned on/off, and double.

• No much effect except 3rd config quarter region.

Systematics on Light cross-talk• Compare results with cross-talk correction turned on/off, and double.

• A clear change on constant term with 3rd config central region, thinking why…• No much effect for others.

Systematics on saturation correction (1)• Signal in ADC counts is converted to num. of fired pixels to apply MPPC

saturation correction.• d-values = ADC counts for 1 p.e. (see reference) obtained with LED gain

measurement system: dlow-gain [ADC counts] = dhigh-gain / Cinter

= 14.4 +- 1.5 for fiber readout module 15.8 +- 1.6 for direct readout module 18.1 +- 1.9 for fiber readout module• Note that only ~5% of whole channels have LED system at DESY BT.• ~10% uncertainties, mainly come from inter-calibration factor.

Vbias = 76.75 Vdhigh-gain = 206.9

Systematics on saturation correction (1)

• No much effect among all.

• Change dlow-gain for + one standard deviation of and compare results.

Systematics on saturation correction (1)• Change dlow-gain for + one standard deviation of and compare results.

• Some amount of effect, which is not negligible.

Systematics on saturation correction (1)• Saturation curves were measured for each of 3 configurations after the beam test (see reference for detail)

Npix = 2072.8 (fiber readout) = 1677.2 (direct readout) = 2270.5 (extruded)

Npix = “effective” number of pixelsx = ADC / dlow-gain

Systematics on saturation correction (2)

• This source dominates overall uncertainty on deviation.

• Just take two extreme cases, change Npix for all the configurations :

Npix = 1600 (assume no enhancement of Npix) or 2270

Systematics on saturation correction (2)

• Effect is non-negligible.

• Just take two extreme cases, change Npix for all the configurations :

Npix = 1600 (assume no enhancement of Npix) or 2270

Deviation including all uncertainties

• We can say “Linearity is confirmed to be within + 2%”.

Resolution – plot ONLY stat. uncertainty

• Same with one what we already have in CAN-012.• Systematics must be added in terms of stat and const .

Resolution statistical and systematic uncertainties

• Systematics from MIP calibration and temp. correction are small enough, while others gives effects of order 0.1 ~ 1 %.

Summary• Plots and tables on systematics study are being finalized.• Dominant uncertainty on deviation comes from uncertainty of effective num. of

MPPC pixels, but still deviation stays within +2%.• For resolution, cross-talk and saturation correction are dominant on systematics.• Issues & to-do list:

– Are evaluation method all correct ?– Behavior of 3rd config module on x-talk correction (page 10) – why?– Npix region is reasonable ?

– Systematics from strip response non-uniformity ?– CALICE note for systematics.– Paper draft – version 0.5 ready for revision up to section 3. Working on other sections.

• ==> sys_MIP.systxt <==• 2 0 0 0.0095387 -0.0095387 0.0212333 -0.0212333• 2 1 0 0.0133516 -0.0133516 0.022889 -0.022889• 2 2 0 0.0680983 -0.0680983 0.0577163 -0.0577163• 3 0 0 0.0184793 -0.0184793 0.016356 -0.016356• 3 1 0 0.0164871 -0.0164871 0.0167485 -0.0167485• 3 2 0 0.0286047 -0.0286047 0.0409721 -0.0409721

• ==> sys_Npix.systxt <==• 2 0 0 0.0527009 -0.2417 0.62048 -0.15401• 2 1 0 0.0725001 0 0.00740997 -0.26662• 2 2 0 0.0048995 -0.5437 0.65224 0• 3 0 0 0.059098 -0.530101 1.09924 -0.19962• 3 1 0 0.0734001 -0.00990033 0.0232298 -0.28046• 3 2 0 0 -0.09 0.44967 0

• ==> sys_dval.systxt <==• 2 0 0 0.0347003 -0.0764996 0.2186 -0.1408• 2 1 0 0.0211 -0.0444993 0.118089 -0.09447• 2 2 0 0.2212 -0.1128 0.17426 -0.18035• 3 0 0 0.0764996 -0.129502 0.34429 -0.24733• 3 1 0 0 -0.0421003 0.10988 -0.0535503• 3 2 0 0.011 -0.0364006 0.0818001 -0.04023

• ==> sys_temp.systxt <==• 2 0 0 0.0229901 -0.0229901 0.00844141 -0.00844141• 2 1 0 0.0122069 -0.0122069 0.0222885 -0.0222885• 2 2 0 0.0939667 -0.0939667 0.0409135 -0.0409135• 3 0 0 0.0417832 -0.0417832 0.0170234 -0.0170234• 3 1 0 0.0164397 -0.0164397 0.0158716 -0.0158716• 3 2 0 0.0410246 -0.0410246 0.0515202 -0.0515202

• ==> sys_xtalk.systxt <==• 2 0 0 0.0376001 -0.0612989 0.27904 -0.29048• 2 1 0 0.101301 -0.074099 0.0636995 -0.0302803• 2 2 0 0.202399 -0.0134006 0.65127 -0.76918• 3 0 0 0.1592 -0.080201 0.22214 0• 3 1 0 0.0534996 -0.00880063 0.40214 -0.0551302• 3 2 0 0.0259995 -0.00279993 0.41221 0

Review – what we havefrom CAN-012

Pseudo-experiment overview• Applicable for systematics from MIP calib. and temperature

correction.• Just randomly change parameter channel-by-channel, and

perform pseudo-experiments.• See variation (RMS) in terms of resolution and linearity.• How many pseudo-experiments?

Assuming variation follows Gaussian distribution, uncertainty of variation is (N = num. of pseudo-experiments)

For a moment, take N=20Which gives “uncertainty of uncertainty”of ~16 %.