Calibration readiness for Run 10, achieved resolution and incoming improvements

Speaker : Gene Van Buren ( BNL )


Talk time : 12:00, Duration : 00:20

Run 10 Calibration Deliverables

A report on deliverables and their scheduled expectation of progress using Figures of Merit (FOM).

Mid-rapidity tracking (TPC Momentum Resolution & Biases)
FOM: ΔpT/pT2
  • comprised of: IntrinsicAlignmentSpaceCharge & GridLeak
  • Intrinsic for magnet at full scale is probably a little bit better than the measured ~0.013 for globals, and ~0.0045 for primaries (see You do not have access to view this node), since those include some Alignment and SpaceCharge & GridLeak.
  • Expect 11 and 7.7 GeV primaries to be only a little better than globals until beamline is in place.
  • Alignment now believed to be contributing about ±0.002. Goal is to bring it down to about ±0.0005.
  • Only portions of the FastOffline production (near end of dataset) may have the "now" values.
  • See Delivery Schedule below.
TPC PID (dE/dx)
FOM: resolution for straight-up, full length tracks
  • Final achievable resolution is unknown; ~7% is used as a placeholder guess
  • Almost none of the FastOffline production have the "now" values.
  • See Delivery Schedule below.
TOF PID
FOM: timing resolution
  • Final achievable resolution is unknown, but only a smalll improvement (a few ps) can be expected († a longer comment on this can be found below).
  • FastOffline production can be analyzed with afterburner to achieve the "now" values.
  • See Delivery Schedule below.
Forward tracking
FOM: FTPC calibrations
  • Done.
  • Only portions of the FastOffline production (near end of dataset) may have the "now" values.
PMD
FOM: PMD calibs
  • Done in a few weeks.
EMCs
FOM: gains
  • Done (using Run 9 values, but will be checked later).

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Run 10 Calibration Delivery Schedule

200 GeV (FF+RFF)
  • ΔpT/pT2
    • now: Intrinsic ⊕ 0.003 ⊕ 0.002
    • a few weeks: Intrinsic ⊕ 0.002 ⊕ 0.0015
    • a few months: Intrinsic ⊕ 0.0005 ⊕ 0.0007
  • dE/dx resolution
    • now: 7.49%
    • a few months: ~7%
  • TOF resolution
    • now: 85 ps
    • a few months: small improvement
62 GeV
  • ΔpT/pT2
    • now: Intrinsic ⊕ 0.003 ⊕ 0.0015
    • a few weeks: Intrinsic ⊕ 0.002 ⊕ 0.0015
    • a few months: Intrinsic ⊕ 0.0005 ⊕ 0.0007
  • dE/dx resolution
    • now: 7.5-8%
    • a few weeks: ~7.25-7.5%
    • a few months: ~7%
  • TOF resolution
    • now: 87 ps
    • a few months: small improvement
39 GeV
  • ΔpT/pT2
    • now: Intrinsic ⊕ 0.003 ⊕ 0.0015
    • a few weeks: Intrinsic ⊕ 0.002 ⊕ 0.0015
    • a few months: Intrinsic ⊕ 0.0005 ⊕ 0.0007
  • dE/dx resolution
    • now: 7.23%
    • a few months: ~7%
  • TOF resolution
    • now: ? (didn't find the number, but probably ~80 ps)
    • a few months: small improvement
7.7 GeV
  • ΔpT/pT2
    • now: Intrinsic ⊕ 0.003 ⊕ 0.000
    • a few weeks: Intrinsic ⊕ 0.002 ⊕ 0.000
    • a few months: Intrinsic ⊕ 0.0005 ⊕ 0.000
  • dE/dx resolution
    • now: 7.25-7.5% (guess based on 39 GeV)
    • a few months: ~7%
  • TOF resolution
    • now: ~77 ps
    • a few months: small improvement
11 GeV
  • ΔpT/pT2
    • now: Intrinsic ⊕ 0.003 ⊕ 0.000
    • a few weeks: Intrinsic ⊕ 0.002 ⊕ 0.000
    • a few months: Intrinsic ⊕ 0.0005 ⊕ 0.000
  • dE/dx resolution
    • now: 7.25-7.5% (guess based on 39 GeV)
    • a few months: ~7%
  • TOF resolution
    • now: unexamined
    • a few months: small improvement

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Task Milestones

Time estimates are very rough guesses: always expect something new...

  • A: TPC FF & RFF preliminary Alignment (now + 2 weeks)
  • B: TPC FF & RFF final Alignment (A + 2-10 weeks = 4-12 weeks)
  • C: TPC 200 GeV FF & RFF intermediate SpaceCharge & GridLeak (now + 2 weeks)
  • D: TPC 200 GeV RFF final SpaceCharge & GridLeak (B + 2 weeks = 6-14 weeks)
  • E: TPC 200 GeV FF final SpaceCharge & GridLeak (D + 2 weeks = 8-16 weeks)
  • F: TPC 62 GeV final SpaceCharge & GridLeak (E + 2 weeks = 10-18 weeks)
  • G: TPC 62 GeV preliminary dE/dx (now + 2 weeks)
  • H: TPC 200 GeV final dE/dx (E + 2 weeks = 10-18 weeks)
  • I: TPC 62 GeV final dE/dx (H + 2 weeks = 12-20 weeks)
  • J: TPC 39,11,7 GeV final dE/dx (B + 2 weeks = 6-14 weeks)
  • M: TOF 7 GeV preliminary calibs (now + 1.5 weeks)
  • N: TOF 200 RFF GeV final calibs (D + 2 weeks = 8-16 weeks)
  • O: TOF 200 FF GeV final calibs (E + 2 weeks = 10-18 weeks)
  • P: TOF 62 GeV final calibs (F + 2 weeks 12-20 weeks)
  • Q: TOF 39,11,7 GeV final calibs (B + 2 weeks = 6-14 weeks)
  • T: BeamLine 39,7 GeV preliminary (A + 1 week = 3 weeks)
  • U: BeamLine 11 GeV preliminary (end-of-11-GeV + 0.5 weeks = ~5 weeks)
  • V: BeamLine 39,11,7 GeV final (B + 1 week = 5-13 weeks)
  • X: PMD 39 GeV final calibs (now + 2 weeks)
  • Y: PMD 11 GeV final calibs (Z + 2 weeks = 6-7 weeks)
  • Z: PMD 7 GeV final calibs (end-of-7-GeV + 2 weeks = 4-5 weeks)

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† A few words on TOF resolutions:

Timing resolution with the TOF is a combination of the VPD (start-side) and TOF (stop-side) components. The start-side resolution can vary due to different collision conditions, while the stop-side should only vary due to the accuracy of the calibration. Systematic mis-calibration of the TPC (e.g. misalignment) can introduce systematic biases in the time/pathlength measurements by the stop-side TOF system, so it is important to get the TPC calibration correct.

Stop-side resolution can be impacted prominently by any degradation of the TPC projection in Z, which comes into the calibration of the TOF T-to-Z correction, but there is little reason to expect much improvement in TPC Z projection resolution (though a possible offset is being studied presently) . However, the stop-side resolution is largely independent of transverse biases, which get calibrated into alignment and then only come in through higher order terms such as relative angle between a TPC track and a TOF tray, so only small further improvement in the resolution (of perhaps few ps) can be made once the TPC calibration has improved. Different biases in different TOF trays could be considered as part of an overall resolution (dispersion) in the full distribution of 1/beta measured by TOF, and that could represent an FOM for the combined TOF-TPC systems.