pyRUMP

Measured data (black) vs. a pyRUMP simulation (red) of a Si / Ru / Mn_2.74Pt₁ / Ru stack.

A clean Python reimplementation of RUMP, the Rutherford backscattering spectrometry (RBS) simulation and analysis package originally written by L. R. Doolittle and M. O. Thompson at Cornell.

The original is ~22k lines of unmaintained C from the late 1980s, with no active support. This reimplementation is written using Claude Code and reproduces RUMP's physics as a tested, importable Python library, with both a batch CLI and RUMP's own interactive shell. It runs on Windows, macOS, and Linux.

Quick start

pip install pyrump

Requires Python 3.9+; numpy, scipy, and matplotlib are installed automatically, along with the physics data tables pyRUMP needs at runtime.

pyrump                         # the interactive shell, from any directory
Your wish? cd examples
Your wish? xeq MnPt.RBS         /* load the measured spectrum, above    */
Your wish? sim get MnPt.lcm     /* load its 5-layer sample description  */
Your wish? compare              /* data vs. simulation, with residuals  */

Buffer 0 is always the simulation and recomputes itself when the sample or the active buffer's parameters change — there is no "simulate" command, exactly as in the original.

Or drive it as one-off batch commands:

pyrump simulate sample.lcm --energy 2.0 --beam 4He -o out.rbs
pyrump fit sample.lcm measured.rbs --vary thickness:0 --window 190 226
pyrump plot measured.rbs --compare out.rbs -o comparison.png
pyrump convert measured.rbs measured.dat

Documentation

The full manual — interactive shell reference, CLI and Python API, worked examples, the physics writeup, and the list of RUMP quirks and defects found while porting — is at https://ikost.github.io/pyRUMP/.

Contributing

pip install -e ".[dev]"
pytest              # unit tests, no external dependencies
ruff check .

Oracle-comparison tests (pytest -m oracle) need the RUMP C source, which isn't redistributed here — see Design and validation. They skip cleanly when it's absent, so it's not needed for everyday development.

Licensing and provenance

pyRUMP is MIT licensed, and an independent reimplementation: it is not affiliated with, endorsed by, or derived from the RUMP source distribution. See Licensing and provenance for the full story, including bundled data-table provenance.