jaxrts

A Python package for simulating X-ray Thomson scattering (XRTS) spectra of dense plasmas, heavily relying on jax.

<p align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="doc/source/images/jaxrts_logo_bright_text.svg"> <img src="doc/source/images/jaxrts_logo.svg" width="600"> </picture> </p>

Disclaimer

This module is still under active development and should be considered experimental, both in its implementation and its dependencies. The package presented here represents an effort to encapsulate published XRTS theory into accessible code for comparison with experimental results, as the state-of-the art software for this purpose, the Multi-Component Scattering Spectra Code (MCSS) by Dave Chapman is not publicly available.

This project would not have been possible without the pioneering work of D. Chapman, G. Gregori, K. Wünsch, and D. O. Gericke. A full bibliography can be found under src/jaxrts/literature.bib.

The code was written by Samuel Schumacher and Julian Lütgert in the High Energy Density Group of Dominik Kraus at the University of Rostock.

<p align="center"> <img src="getting_started.png" width="600"> </p> <h5 align="center">An example result</h5>

Documentation

The documentation can be found in the doc directory and online. To generate it for yourself, just run

poetry run make html

in the doc directory, after installing the module.

Installing

We recommend to install the module using poetry by calling

poetry install

in the root of this repository.

This will create an virtual environment for the project and install the required dependencies. To execute commands within the virtual environment, prefix them with poetry run.

However, you should also be able to just pip install the module, after cloning it:

pip install -e .

This -e flag installs the module in 'edit' mode, i.e., changes you made are available without the need of reinstalling the package.

Getting started

The jaxrts module provides a user with two classes, a Setup and a PlasmaState. While the former specifies the probing energy and measurement grid, scattering angle and instrument function, the latter defines the state to be probed, and allows for adding Models as keys to the plasma state. To calculate a spectrum, use the PlasmaState.probe() method.

A simple example (which generated the figure above) can be found at doc/examples/plot_getting_started.py. More examples can be found in the doc/example directory.

To get an overview over all the models available, we recommend building the documentation and opening doc/build/html/models.html. This page should list all the available model keys and the models which are allowed.