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Trigger report from Run2009

Trigger report from Run2009. D. Nicolò Pisa. Outlook. New features hardware firmware Performance event reconstruction observable resolution efficiency a novel trigger: a -calibration with beam on Run summary Todo’s for Run 2010 automatic gain adjustment dead time reduction.

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Trigger report from Run2009

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  1. Trigger report from Run2009 D. Nicolò Pisa

  2. Outlook • New features • hardware • firmware • Performance • eventreconstruction • observable resolution • efficiency • a novel trigger: a-calibration with beam on • Run summary • Todo’s for Run 2010 • automatic gain adjustment • dead time reduction Trigger report ...

  3. Hardware • Optimization of FADC dynamic range • needed to be improved from Run 2008 • further increase of XEC light yield towards nominal value • construction of newly designed FE cards with (0÷2V) swing • (used to be (0÷1V) beforehand) • 400 brand-new cards mounted on XEC Type1 channels • (inner PMT 1:1 + side&outer PMT 4:1 inputs) • board reworking • transmission of FADC selection bit • operated from the beginning of CEX run (15/10/09) with all XEC channels in the extended range • Resetting of active splitters • CM voltage changed to fit FADC range  linearity from a few up to 130 MeV Trigger report ...

  4. New FE scheme Low-pass filters (BW = 22 MHz) VOCM = VREF/2 Test and installation completed in October Trigger report ...

  5. Board modification User-programmable bit to select AD9218 gain • 0 = [0:1V] • Z = [0:2V] completed in September Trigger report ...

  6. Eγ-linearity in Run 2009 - p 0 n  γ γ - p  γ n 11B(p,γ)12C • offset < 150 keV • int. non-linearity < 1% 7Li(p,γ)8Be Trigger report ...

  7. Online Eγ resolution 7.5% FWHM Trigger report ...

  8. Eg efficiency • Gaussian smearing at threshold • Correlation with offline TRG energy • 6% FWHM: compatible with 0sR trgenetotalsum.energy (MeV) Trigger report ...

  9. Effect of saturation ISAT = 0 ISAT = 1 2.5 MeV shift • 23% of events with at least one saturated channel (@ 55 MeV) • threshold reduced by 3.5 MeV in the case of saturation Trigger report ...

  10. Todo • use QEs for PMT calibration • XEC stable, but need to compensate for gain variation • forced to reduce the threshold during Run 2009 Trigger report ...

  11. Δteγ |ΔT (LXe-TC)| expected to be flat (due to accidental background) σ(ΔT) = (3.1±0.1) ns (used to be 3.8 in run 2008) Online offset changed during the run Both edges are > 2.8 σout of the signal (as determined by the RMD peak) εΔT> 99.5% start end Δt (ns) Δt (ns) Trigger report ...

  12. zTC calibration • z-positron obtained by using TC bars based on λlog(Qu/Qd) • need to • equalize PMT • use LUTs (one a bar) to implement the log function • the absorption length was computed for each bar by using cosmic muons • may differ significantly one each other (ranging from 0.5 to 1m)  different LUTs for each bar been implemented since Dec 14 • used to be the same beforehand  same λ for all bars • z-resolution improved from 7.1 to 5.5 cm (might be 2.5 cm by using TC APDs) Trigger report ...

  13. Cosmic muons common LUT individual LUTs s = 7.1 cm s = 5.4 cm • DZ (cm) • DZ (cm) Trigger report ...

  14. MEG events common LUT individual LUTs s = 7.1 cm s = 5.6 cm DZ (cm) DZ (cm) Trigger report ...

  15. TC inefficiency • 48 bits serialized by DS90CR481 on 8+1 LVDS connections • 4.8 GBits/s Wrong LVDS transmission TC Type1 board  Type2 board • 6 bits missing  only te+ info got screwed • TC acceptance loss 7/30 = 23.3 % in the data collected from 5thto 27th November Transmission check implemented • data bus are recorded in memory buffers on both source and destination boards • memory comparison operated on-line by the Event Builder • check active on pedestal trigger (0.1 s-1) from then on Trigger report ...

  16. e+-γ direction • based on a LUT to associate XEC PMT  (φTC, zTC) • LUT generated by assuming σ(zTC) = 7.3 cm • efficiency computation based on a sample of Michel’s a) search for “good quality” track candidates (χ2, matched extrapolation to TC) b) track a backward hypothetical γfrom the decay vertex; c) γ hit position  XEC PMT index; d) XEC PMT index  search for hits on the TC in the LUT • turns out to be (88 ± 1)% • don’t expect significant variation with improved tracking • improved resolution (σ(zTC) =2.5 cm) in Run 2010 should result in a significant efficiency improvement Trigger report ...

  17. Performances: 2008 vs 2009 Trigger report ...

  18. -trigger • /γseparation based on different scintillation decay time = 22 ns, γ= 45 ns • couldn’t be operated last year due toionization quenching  γ Trigger report ...

  19. On-line -rings -selection efficiency  90% with the beam on! residual contamination from beam-related background < 20%  suppression by 3-orders of magnitude Trigger report ...

  20. After off-line cut Trigger report ...

  21. Physics Run Start Run 50180 2009-10-29 11:27:59 End Run 64482 2009-12-22 11:25:33 Total ‘wall clock time’ (WCT) 4 669 056 s ~ 54 d Trigger report ...

  22. DATA runs • Physics run Period (#50180 - #64482) • Time fraction dedicated to different run types XEC calib 10.3% DC calib 0.1% TC calib 3.0% Trigger report ...

  23. DAQ summary Total ‘wall clock time’ (WCT) 4 669 056 s Total ‘beam ON time’ (BOT) 4 119 567 s (88% of WCT) Total of Stop-Start time (DT) 3 961 022 s Total of Stop-Start time (MEGT) 3 354 497s Fractions: DT / WCT84.8 % (running DAQ) MEGT / BOT81.6 %(running MEG when beam on) other / BOT 1.1 % (beam related calibrations) LT / BWCT 81.5 %(DAQ livetime fraction) Leading to LT/BOT = 66 % LT/WCT = 59 % slightly increased w.r.t. Run 2008 LT/WCT = 49 % (55% if we exclude RMD runs) Trigger report ...

  24. How to improve? • DAQ • reduce inter-run gap (6.8 s, 2.1% deadtime) • and/or wake-up time (2.1 s, 0.6% deadtime) • (alternatively) have longer runs  larger filesize • Digitizer read-out • reduce read-out time new memory arrangement with multi-event buffering Deadtime26 ms  15 ms  17%  10%  demands for a major firmware upgrade Trigger report ...

  25. Outlook • Hardware • extended and programmable FADC range • Firmware • reconstruction improved w.r.t. Run 2008 • Stronger background rejection • Higher efficiency • -trigger implemented • efficiency > 80% (even higher in the case of side PMTs) • 3-order of magnitude suppression of beam-related background • don’t need dedicated runs any longer • Further improvements • zTC reco by TC-APDs • periodical XEC PMT gain calibration • reduce deadtime Trigger report ...

  26. Backup slides

  27. TC equalization • PMT equalization with cosmic muons, 2 factors • Assume ETC = sqrt(A0 * A1) and ZTC = ln(A0 / A1 ) • Use of cosmic muons • Equalize the landau distr. • Center at 0 the Z distr. Trigger report ... • Offline TRG ETC (a.u.) • Offline TRG ZTC (a.u.)

  28. Beam duty Beam ON Start 2009-10-29 11:27:57 End 2009-12-22 11:27:32 Total ‘proton time’ (PT) 4 669 175 s Total ‘beam ON time’ (BOT) 4 119 567 s (p-current>1500 mA) Fraction of ‘beam ON time’ (BOT/WCT) 88 % Trigger report ...

  29. MEG run benchmark 216 contiguous MEG runs in December Start run 63481 2009-12-18 19:58:20 End run 63696 2009-12-19 15:33:13 Benchmark ‘wall clock time’ (BWCT) of 70 493 s Live Time (LT) 57 458 s Total Time (TT) 68 568 s Sum of Stop-Start time (DT) 69 022 s Fractions: LT / TT 83.8 % (event read out, coherent with DAQ rate) LT / BWCT 81.5 % (event read out + DAQ) DAQ contribution to Dead Time DAQ wake up time (DT-TT)/2162.1 s DAQ inter run gap (BWCT-DT)/2156.8 s Trigger report ...

  30. Diff. driver Proces. Algor. • FADC • LVDS Tx Cyc. buff Cyc. buff • Type1 • FPGA Proces. Algor. Proces. Algor. • LVDS Rx • LVDS Rx • LVDS Tx • LVDS Tx Cyc. buff Cyc. buff Cyc. buff Cyc. buff • Type2 • Type2 • FPGA • FPGA Cyclic buffers Type1 layer Analog inputs Type2 layer Final Type2 Trigger output Trigger report ...

  31. TC inefficiency • TC trigger problem • New degrader • Red TRG 22 • Black TRG 0 • Direction match LUT OK • On Type2-0 • MC generated • Symmetric US/DS • Time match • On Type1-3 OK • Transmitted through LVDS Error • Type 1-3 Board replaced on Nov. 27th • Efficiency loss 7/30 = 23.3 % Trigger report ...

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