Calorimeter Status

1. Calorimeter Status Pierre Pétroff, LAL ORSAY D∅ France 25-26 Mai, 2004 on behalf of the dream team : Ashish, Chris, Dean, Haryo, Jean-Roch, Junjie, Kirti, Mike, Nikola, Robert, Slava, Silke, Subhendu + Dan and Philippe for L1 trigger + Ursula and Taka for the database

2. CALOP at work • Electronics survey • slow control • ped_viewer study of peds variation in time • dq_calo & L1 Cal examine monitoring programmes • cal_elec • Calibration • Determination of the adc response and NLC coefficients with the pulsers • pattern optimization and gain8 – gain 1 switching • physics (3 sampling data) and calibration timing • toward a “total” calibration • Electronics noise study • electronics coherent noise • “stochastic” coherent noise • Use of physics objects to study (and reduce ?) the constant term • E/p variation vs Crate/ADC/BLS/(Tower) with electrons from W/Z • Electronics upgrade: Proposition of a new adc readout

3. Slow control-peds survey Silke/Haryo and Chris(ped_viewer) Peds are stable ~0.1 adc count over months but we are able to tag channels with peds drift vs time very powerfull tool ! crate 1/adc 0/bls1/ tower1 Adc mean value Fixed ! days

4. Monitoring programmes see Slava Shary’s talk • dq_calo very sophisticated monitoring prog. • proof of efficiency  problems fixed before our sleuths of the data quality detect it ! • useful for offline analysis too  tag coherent noise Mean energy occ 0 bias trigger Jet trigger + Unsupressed trigger + All triggers Saturday May 8th

5. em L1 trigger L1 cal examine (Chris) -6,25

6. still pending like a Democles’sword ! toroid noise ~ March 1rst Dan Edmunds EM TT Had TT ~4pb-1 data taken without toroid and coil fields …not analyzed up to now !

7. harness problem in crate 9 bad contacts in low voltage connectors at the level of BLS backplanes some time to time ..nedd to be fixed during the long shutdown

8. Back to the checkerboard issue If the “Digital Timing Strobe” arrives after the gain switching signal:  the ADC can get incorrect gain switching  checkerboard pattern strobe t >45ns diff. gain signals pt electrons>25 GeV mainly in carte 10 (North EC) fixed by a new software version see Jean-Roch Vlimant’s/Jan Stark‘s talks in CALOP/CALGO and ADM meetings

9. normal channel ×1 ×8 problem! ×1 ×8 Gain Switching • 12-bit ADC • 2 gains ×8 and ×1 to have an effective 15-bit dynamic range • Mechanism • retrieve first ×8 • if too high (>~3100) retrieve ×1 • if ×1, ADC counts multiplied by 8 • Problem: ×1 retrieved, but not multiplied by 8 • Under study (along with Dean S.) (Some problematic d.c. replaced => turned to Normal )

10. x8-x1 gain switching - pattern optimization - bad channelsfixed ! x1 x8 adc dac

11. LinADC vs DAC Calibration of electronics readout with pulser system see Jean-Roch/Robert’s talk Looks simple !  apply same known calibration pulse to all channels  correct for response variation • 4 fitted parameters • a8 = slope in gain 8 ~ 0.25 (0.1 for ICD) • g = a8/ a1 very close to 1 (precision resistor) • Parameter p allows for fluctuations in voltage input in SCA (~ –2V) for 0 signal • v0 (“ofy”) to account for non zero DAC output • “ofx” DAC set for current output problem of updating and time necessary to perform the pattern runs .. now done and updated in the database … ADC ofy DAC ofx

12. slopes vs Preamp specie: B A C F E D G H I • slopes • rms vs PA specie • gain 8/gain 1 • pulser • offsets • pattern • SCA (pipeline) • non linearity • non uniformity

13. 35 ns EM2 A channels h = 1.5 and h = 3.5 black arrow purposefully misplaced t/ns The calib and physics signals are not using the same path Need to correct for timing variation channel/channel in calib AND physics timing issues to be addressed see Robert’s talk calib • Due to • difference in cable length + electronics • global sampling time • Stephanie produced a file • ~ 1% correction • not used in reco ? • not NLC corrected • Same for physics: simulation and triple digitization data (Shaohua Fu) • ~1% correction • for all channels • not used in reco • not NLC corrected

14. Amplitude correction 132 ns 132 ns Timing difference normal early late timing correction of physics signal • Triple digitization sample • Same signal taken three times: 132 ns in between; read out in the order of normal  early  late. • To study the timing of calorimeter: if the timing is not centered at the peak, we need to correct the signal amplitude with a simulated physics signal • Plan: to correct timing channel by channel in d0reco. simulation

15. Measured Timing • Timing difference = measured timing  simulation timing • Signal correction factor = measured amplitude / simulation peak • The list of amplitude correction for all channels is ready

16. calib phys toward a full calibration 1. use delay ramps to compute electronics transfer function (channel per channel!) 2. predict physics pulse shape (but not absolute timing) 3 adjust physics timing using triple digitization events 4. correct for channel to channel variation at sampling time see Robert’s talk

17. Channel noise • ADC noise depends on the cell size and/or the preamp:Larger cells -> larger noiseCoarse hadronic • Amplified by cal_weights(total to visible energy ratio)EM/HAD ~10 MeV/ADCCH ~ 30 MeV/ADC • ×1.6 for non linearity Noise/ADC Noise/GeV Robert

18. coherent noise study see Mike Arov’s talk • total coh. noise • coh. noise ratio at fixed SCA cell mean ~0.6 adc count aim to get a map view in the calo vs time of the coherent noise by crate and layer fixed cell/non fixed cell~0.3 ~ 30% ~ 60% adc fixed cell “bad SCA”

19. What’s wrong ? or how to tag it ?CALGO workshop 05/11-12/04PP LAL Orsay Junjie constant term ~4% in CC • hardware • SCA….timing…etc ..(remember the checkerboard problem !) • calibration • timing ..bad NLC…bad adc response correction • software • Z method etc .. • or some physics effect like charge collection at the edge of the phi sectors ? take profit of the very high statistics of electrons from W/Z to study the calo response and try to find correlations between electronics/pulser signal and physics !

20. Physics objects as a tool to understand (or to cope with) electronics response charge collection effect / RunI in the phi cracks in CC 32 modules delta phi = 0.2 E/p study with e+- from W/Z Profile: same plot but with E/p fitted fid cuts charge collection simulation in progress ..

21. “old” study (Dec 2003) with Kolmogorov teston e pt from W In CC pt spectrum vs phi sector thanks to Sergey Burdin..! ~same study presented by Junjie yesterday (likelihood method) we used one phi sector as ref. and not pmcs W pt spectrum looks like 2-7-3 at 17 in phi sector unit ref W ptblue one phi sector red ref sector phi sector

22. in CC diff fit E/p per adc-E/p all crates use tracker .. In agreement with Jan’s study with e from Z but with much less statistics e+- from W/Z adc adc 2 E/p gaussian fit crate 9 ~3000 evts/adc diff adc 7

23. down to BLS ! .. Crate 2 adc 7 bls 3 “good” one 2-7-2 2-7-3 very ugly ! 3 times less stat ! crate 2 3 8 9 adc 0-11 12-23 24-35 36-47 As an example …. WHY ???

24. at the BLS level (4 towers)  tower level -> layer level (use skimmed rootrees  get cells) E/p(BLS)-E/p mean Preliminary sigma~2.4% bad BLS ? still more work !! 384 BLS  4 CC crates Z w=3.4 GeV uncorr Z w =3.2 GeV corrected better by 6%  resol on E improved by ~ sqrt(2)*6%= 8%

25. As a conclusion ……use physics objects not only to tag bad electronic channels but to understand the contribution of the electronics to the C term We should be focused on one topics which is : What’s wrong in the electronics which could fake the calo resolution ? If not understood and corrected The W/Z and top physics are very strongly compromised Juniie Zhu special session at Fresno on the calo resolution A = 20%/sqrt(E) C = 3.88 ±0.18 % If A = 15%/sqrt(E) C = 4.13 ± 0.22 % Likelihood on the Z mass with PMCS/data

26. Conclusion ..if any .. • with enough stats able to tag bad BLS ..and even bad towers (to be done) + new “calib factors” calculation • limited by the adc/bls/tower id ..could explain why the improvement on the Z width is 6% only • skim TMB/roottrees to get full info on calo cells • tag the right tower • “calib” cell/cell • test these new calib factors on the J/Psi • Z calibration ..something wrong ??? • last but least  understand what’s in electronics is responsible of this non uniformity ..”timing” ?? • ++ etc ….. !! Maybe the method is WRONG !!! Many cross checks have to be done … • hope some progress at Fresno : Calo resolution session chaired • by Jan and myself.

27. Fit Results: Results CPS has saturation bug but use ad hoc correction… • Fit Results: • Raw: Mean -0.00060  0.00047 Sigma 0.0346  0.00040 • No CPS: Mean -0.00081  0.00046 Sigma 0.0342  0.00039 • CPS: Mean 0.00004  0.00044 Sigma 0.0313  0.00035 • Improves 0.3% (10% relative)

28. Channel noise 31 9 26 28 25 23 28 32 17 33 40 27 26 26 28 30 24 25 29 very high noise 96 91 89 107 104 117 ~40 70 ~90 • 1st line = raw noise/ADC 2nd = cal weights 3rd = noise/GeV >100 MeV Robert