Fall 2014 Commissioning Simulations

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This page is for the organization and sharing of information about simulations for the Fall 2014 Commissioning data.

General Info


  • Software - static conditions page
    • Note that the special sim-recon & HDDS branches sim-recon-commissioning and hdds-commissioning are required to analyze this data, as they have special configurations for the thin plastic target used instead of the nominal LH2 target.
    • Default JANA_CALIB_CONTEXT="variation=mc calibtime=2014-11-06"
  • Assume unpolarized photon beam 1-10 MHz/GeV at the endpoint
    • BG parameters: min E(g) = 1.2 MeV, BGRATE 1.10, BGGATE -800. 800.
  • Generic bggen events were generated with different magnetic field settings - see conditions page for details on run and file numbers.

How to Access Simulated Data

The files can be found at the following location:


The subdirectories most people are probably interested are:

  • smeared - Output of mcsmear
  • rest - Fully reconstructed REST files

How to Run Over Simulated Data

To set up the environment on the JLab CUE, using the following script

source /group/halld/Software/conditions/detcom/01/conditions/setup_jlab.csh

Since each run is generated with a different non-standard magnetic field, your analysis program (e.g. hd_root) must be passed the following parameters:

  • Run 9101 (1200A): -PBFIELD_MAP=Magnets/Solenoid/solenoid_1200A_poisson_20140520
  • Run 9102 (No field): -PBFIELD_TYPE=NoField
  • Run 9103 (300A): -PBFIELD_MAP=Magnets/Solenoid/solenoid_300A_poisson_20140819

The environment variable JANA_CALIB_CONTEXT MUST contain a reference to "variation=mc", the default being:

JANA_CALIB_CONTEXT="variation=mc calibtime=2014-11-06"

Beam Simulations

EM Background Simulations

The goal of these simulations is to determine the lowest field at which the solenoid magnet can be run while not having the detector overwhelmed with signals from background beam photons. The FDC and FCAL are the limiting factors.

  • The zero magnetic field simulations described above.
  • 1M each with Solenoid @ 50 A, 100 A, 200 A, 300 A

Other questions

  • What is the background rate with no target?
  • What is the background rate with various targets?

Hadronic Event Simulations

Overall hadronic rate

Reference: Fall 2014 Commissioning Plan

Assume 50 nA CW electron beam

Hadronic Event Rate
1.5 µm Al 10 µm Al 30 µm Al
10mm CH2
2mm CH2
2/7mm CH2
3.4mm graphite

Final States

These reactions can be used either as benchmarks due to their large cross section or are interesting to various subdetectors

  • γp→π+π-p
  • γp→π+π-π0(p), π0→γγ
  • γp→π+π-π+π-(p)
  • γp→ηπ+π-(p), η→γγ
  • γp→K+K-π+π-(p)
  • γp→K+Λ, Λ→pπ-

Special Simulations