Mid-year LDRD: A pilot digital twin for physics-informed ML control of alignment in an FEL beamline

Organization of the repository

The repository contains several folders:

• simulation_scripts: Scripts to run ImpactX or Cheetah simulations of the HTU lattice:

  • htu_lattice.py: File that contains a common definition of the HTU lattice, for both ImpactX and Cheetah
  • run_cheetah_impactx.ipynb: Notebook that shows how to run Cheetah and ImpactX simulations of HTU

• fit_to_experiments: Scripts to fit simulation parameters to existing experimental data

  • compare_sim_exp.ipynb: Notebook that fits simulation to experiments and produces an interactive visualization
  • README.md, environment.yml: How to setup the environment for comparison between simulations and experiments

• RL_controler: Scripts to train an RL agent to match the beam

  • README.md, environment.yml: How to setup the environment

Copyright Notice and License Agreement

BELLA HTU digital twin v1.0 Copyright (c) 2026, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from the U.S. Dept. of Energy). All rights reserved.

If you have questions about your rights to use or distribute this software, please contact Berkeley Lab's Intellectual Property Office at IPO@lbl.gov.

Please find the full copyright notice in NOTICE.txt and the full license agreement in LICENSE.txt.

The SPDX license identifier is BSD-3-Clause-LBNL.