Repository Overview

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CLAS12 sample generator

This project prepares CLAS12¹ simulation samples for the e4ν collaboration. It prepares truth-level particles as LUND files and submits them for GEMC² detector simulation and COATJAVA³ reconstruction, with explicit sample and detector settings. The project provides two workflows: creating LUND files and submitting CLAS12 detector simulation and reconstruction jobs.

Workflow	What it does	Main result
create-lund	Creates LUND input from random acceptance-test kinematics or converts existing event-generator truth-level data	LUND files and a completion manifest log
submit	Submit simulation and reconstruction jobs to Jefferson Lab’s computing farm (ifarm), using the Slurm job scheduler	GEMC detector simulation followed by COATJAVA reconstruction

The uniform LUND creator makes deliberately unphysical samples that cover configured momentum and angle ranges. The physical LUND converter preserves supported particles from existing event-generator output; it currently reads GENIE GST ROOT trees and does not run GENIE. Both paths use the same target geometry, LUND writer, file splitting, provenance, and completion rules where their meanings agree.

The workflows stop at reconstructed HIPO output, which can be analyzed with CLAS12ROOT. They do not generate physical interactions, calculate detector acceptance, skim reconstructed data, or perform physics analysis.

For the legacy code: see legacy-code-archive tag.

Start here

The code Wiki is the user and developer manual. Its home page gives separate reading paths for running the software and extending it.

For a small uniform run on the ifarm, use the uniform-1e-5986MeV.conf:

source run.csh \
    --workflow create-lund \
    --source uniform \
    --config config/samples/uniform-lund-creation/uniform-1e-5986MeV.conf \
    --events 100 \
    --output /path/to/quickstart-output

run.csh is designed for a disposable ifarm checkout: it discards tracked changes and removes untracked and ignored files, preserving only the checkout's build/ tree, then updates from Git and builds when needed. Full workflow validation happens after this refresh. Commit and push valuable development work before running it, and keep sample output outside the checkout. Local developers should build with CMake and invoke the compiled executables directly.

After LUND creation succeeds, preview simulation submission with the run's lundfiles/ directory:

source run.csh \
    --workflow submit \
    --lund-dir /path/to/quickstart-output/Uniform__1e__5986MeV/lundfiles

Preview is the default. Add --execute only after reviewing the resolved detector settings and output actions.

Useful entry points:

• Quickstart
• Create LUND files
• Submit simulation
• Architecture
• Contributing

The longer command collections under tutorials/ demonstrate every public option. Historical implementations are preserved in the legacy-code-archive tag and are not part of the current manual.

References

1. V. D. Burkert et al., “The CLAS12 Spectrometer at Jefferson Laboratory,” Nucl. Instrum. Meth. A 959, 163419 (2020). doi:10.1016/j.nima.2020.163419 ↩

2. M. Ungaro et al., “The CLAS12 Geant4 simulation,” Nucl. Instrum. Meth. A 959, 163422 (2020). doi:10.1016/j.nima.2020.163422 ↩

3. V. Ziegler et al., “The CLAS12 software framework and event reconstruction,” Nucl. Instrum. Meth. A 959, 163472 (2020). doi:10.1016/j.nima.2020.163472 ↩