128Energy groups
Thermal Compton scattering tables
Multigroup, multiangle
Compton scattering matrices.
MACE: Multigroup-Multiangle Astrophysical Compton-Scattering Evaluator Thermal Compton-scattering tables for multigroup, multiangle radiation transport
Pre-computed scattering cross sections evaluated with the Kershaw–Prasad–Beason thermal Compton kernel. Select temperature, energy, and angle grids, then download ready-to-use NumPy arrays for your transport code.
100Angle bins
64Temperatures
Log-spaceInterpolation
NPYNumPy output
Interactive laboratory
Build Compton scattering matrices for radiation transport.
Configure temperature, energy group, and scattering angle grids. MACE loads pre-computed fine-grid data and performs conservative collapse and interpolation entirely in your browser.
Matrix builder
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Scientific visualization
Matrix explorer
Visualize the scattering matrix: outgoing energy spectra, angular distributions, or full energy-transfer heatmaps for any stored temperature.
Physics and numerics
Deterministic thermal Compton scattering.
Every matrix element retains its physical meaning: the multigroup, angle-binned cross section for photon energy transfer from group \(g\) to group \(g'\) within scattering angle bin \([\xi_{i-1/2},\,\xi_{i+1/2}]\).
Scattering kernel
The Kershaw–Prasad–Beason thermal Compton kernel
The multigroup, angle-binned scattering cross section is defined as:
$$\sigma\bigl(g \to g',\,[\xi_{i-\frac{1}{2}},\,\xi_{i+\frac{1}{2}}];\,T\bigr) = \frac{2\pi \displaystyle\int_{\mathcal{E}_{g-\frac{1}{2}}}^{\mathcal{E}_{g+\frac{1}{2}}} \int_{\mathcal{E}'_{g'-\frac{1}{2}}}^{\mathcal{E}'_{g'+\frac{1}{2}}} \int_{\xi_{i-\frac{1}{2}}}^{\xi_{i+\frac{1}{2}}} \mathcal{K}\;d\xi\;d\mathcal{E}'\;d\mathcal{E}} {\mathcal{E}_{g+\frac{1}{2}} - \mathcal{E}_{g-\frac{1}{2}}}$$
where \(\mathcal{K}(\mathcal{E},\,\mathcal{E}',\,\xi;\,T)\) is the thermal Compton kernel, \(\mathcal{E}\) and \(\mathcal{E}'\) are the incoming and outgoing photon energies, \(\xi = \cos\theta\) is the cosine of the scattering angle, and \(T\) is the electron temperature.
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Multigroup cross section
Energy- and angle-resolved cross sections on a 128 × 128 × 100 fine grid per temperature.
Temperature coverage
64 log-spaced temperatures from 1,000 K to 109 K with log-space interpolation for custom values.
Conservative collapse
Minmod-limited reconstruction with kinematic output assignment for sub-group boundary straddling.
NumPy format
Download as .npy arrays directly loadable with numpy.load(). Edge-case dimension reduction for scalar/1D/2D results.
Accuracy: Collapsing to coarser grids is exact when requested boundaries align with stored fine-grid boundaries. For non-aligned boundaries, the Compton kinematic formula determines output-group assignment; typical relative error on dominant matrix elements is ≤ 5%.
Temperature interpolation: Custom temperatures are interpolated linearly in log-T between the two nearest stored values (adjacent stored temperatures have a ratio of ≈1.25).
Open and reproducible
Compton scattering matrices for astrophysical transport.
MACE provides pre-computed multigroup, angle-resolved Compton scattering cross sections for radiation-hydrodynamics codes. Configure the grids you need and download ready-to-use NumPy arrays, or retrieve the source code and generation scripts.
ComptonMatrixExact
A standalone solver that evaluates the exact thermal Compton-scattering kernel (Kershaw, Prasad & Beason) for arbitrary energy grids, angle discretizations, and electron temperatures. It produces the multigroup cross-section matrices that MACE serves.
GLOW — Group-resolved Low-density Opacity Warehouse
A public library of multigroup opacities extending to low-density astrophysical plasmas. GLOW provides group-resolved opacity inputs for supernovae, tidal disruption events, accretion flows, stellar envelopes, radiative shocks, and other radiation-hydrodynamics problems.