DIRC Software Overview

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Revision as of 11:41, 24 September 2018 by Jrsteven (Talk | contribs) (Software Packages and Setup)

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Software Packages and Setup

The software packages required to run DIRC simulation and reconstruction are a part of standard GlueX software deployment.

  • Packages: hdds, halld_recon, halld_sim, hdgeant4, etc.
    • For the 2018 commissioning period we are using a branch of these repositories: dirc_commissioning_2018
  • Installation instructions and a list of steps to start generating simulation can be found in this README file

The latest version of MC samples which can be studied with this branch are located at:

  • LUTs: /group/halld/Users/jrsteven/2018-dirc/dircsim-2018_08-ver04/
  • Event samples: /volatile/halld/home/jrsteven/2018-dirc/dircsim-2018_08-ver04/

Simulation samples

Generator Number of events (106) Settings Planned usage
bggen 1 General inclusive sample for many studies
gen_2pi_amp 25 ρ → π+π- Pure sample of pions with relevant kinematics
gen_2k 2.5 φ → K+K- Pure sample of kaons with relevant kinematics
k/pi p/m_p4_theata4 0.01 π+/- K+/- particle gun at p=4 GeV, theta=4 degrees, phi = -90 degrees Single particle tests
k/pi p/m_flat 0.1 π+/- K+/- particle gun at p=[0.5,8.5] GeV, theta=[0,10] degrees, phi = [-180, 180] degrees Single particle tests

Analysis Scripts

  • Analysis and calibration scripts should be located in dirc/ directory of hd_utilities

Translation table

  • Initial decoder work ongoing by David

LUT algorithm documentation

  • Writeup from Maria

Studies

A list of DIRC Software Tasks is maintained, which are the required tools necessary for analysis of the commissioning data. Below are some planned/ongoing studies to evaluate the commissioning data.

Mis-alignment effects

  • Goal: Study qualitatively how mis-alignments may impact hit patterns and LUT reconstruction
  • Identify likely mis-alignments and implement in alternative geometries as examples of what we may observe in the data
    • Example mis-alignments: angles of bar box plane, angle between bar box and optical box (at rubber gasket), translation of mirror box in optical box, etc.
  • Develop script which parses text from DIRC_HDDS.xml (applies rotations and translations) and writes new XML file with mis-alignment (Yunjie)
    • Also needs to implement survey results for finalizing geometry at start of run period
  • Generate another sample of MC with modified geometry and use LUT from "as-built" geometry to see how the mis-alignments affect the commissioning observables

Final Alignment

  • Goal: Optimize alignment parameters for positions and angles of all optical components using identified track samples
  • Plan to use Bayesian optimization technique with FastDIRC algorithm (Cris/Yunjie)
    • Closure test with MC by the end of the year?
  • Possible tests using sub-samples for alignment procedure and validation
    • Align optical box components using tracks from single bar, then test alignment with tracks from other bars
    • Align all components using identified pion sample, then test alignment with identified kaon sample

Time imaging map

  • Goal: Study performance of time imaging algorithm as a function of theta, phi (Maria)

Particle ID efficiency

  • Goal: Using well determined reactions determine efficiency vs background rejection for different algorithms