DIRC Software Overview
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Contents
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-ver01/
- Event samples:
/volatile/halld/home/jrsteven/2018-dirc/dircsim-2018_08-ver01/
Generator | Number of events (106) | Settings | Planned usage |
---|---|---|---|
bggen | 1 | General inclusive sample for many studies | |
gen_2pi_amp | 5 | ρ → π+π- | Pure sample of pions with relevant kinematics |
gen_2k | 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 XML (applies rotations and translations) and writes new XML file with mis-alignment
- 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