CERN Prototype

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Select Documents and Meetings

  • 2015
    • DocDB 10385: Brief review of Computing Requirements for the test

Expected Data Volume

Event Size Estimates

Measurement categories are based on slide 9 in DocDB 9993. Estimated events sizes are based on Monte Carlo simulations run previously for the 10kt version of the Far Detector, and are only meant to be precise within an order of magnitude. However, simple channel count and ADC digitization rate considerations do confirm that this is the right scale for the data produced per event (with zero suppression). Based on a MC data point for electrons (including showers) and experience in uBooNE, we can also conclude that the event sizes for single tracks and showers of comparable total energy (contained in the detector) would not be widely different.

Particle Type Momentum Range (GeV/c) Bin (MeV/c) Approx. event size (MB)


p 0.1-2.0 100 1
p 2.0-10.0 200 5
mu± 0.1-1.0 50 1
mu± 1.0-10.0 200 5
0.1-2.0 100 1
2.0-10.0 200 4
K+ 0.1-1.0 100 1


gamma (pi0) 0.1-2.0 100 1
gamma (pi0) 2.0-5.0 200 5

Statistics

In terms of detector characterization, some of the important parameters include energy scale and resolution for both single tracks and showers - hadronic and EM. Let's consider them first (using comments from T.Junk):

  • Energy scale: for Gaussian distribution, uncertainty will be sigma/sqrt(n). Assuming resolution of 1%, and aiming for ±0.1% precision, only 100 events would be needed.
  • Hadronic showers: older calorimeters had resolution of 80%/sqrt(E). Since sampling fraction in LAr TPC is higher, we are likely to do better than this, but still conservatively assume O(10%)/sqrt. Qualitatively, we can follow arguments similar to the previous item. It follows then that O(103-104) events will be enough for the purposes of this measurement. Indeed, looking at typical test beam and calibration practices (per papers published), we see that 104 events is the typical statistics for a given incident beam momentum.