Isotopic Fractionation via ATmospheric Escape (IsoFATE) is a Python code that models mass fractionation resulting from diffusive separation in escaping planetary atmospheres and numerically computes atmospheric species abundance over time. The model is currently tuned to sub-Neptune sized planets with rocky cores of Earth-like bulk composition and primordial H/He atmospheres. F, G, K, and M type stellar fluxes are readily implemented. This code is not yet a Python package, so no installation is required. Simply download the source files to use.
Version 1 can simulate a ternary mixture of H, He, and D (deuterium). Version 2 is coupled to the magma ocean-atmosphere equilibrium chemistry model Atmodeller.
Author: Collin Cherubim
If you use IsoFATE, please cite:
- Cherubim, C.; Wordsworth, R., Hu, R.; Shkolnik, E. (2024). Strong fractionation of deuterium and helium in sub-Neptune atmospheres along the the radius valley, ApJ (https://ui.adsabs.harvard.edu/abs/2024arXiv240210690C/abstract)
There are no formal tutorials for IsoFATE at this time. Please contact me directly at [email protected] for support.
Use "isofate_binary.py" for binary atmospheric mixture of deuterium and helium or hydrogen and helium. Use "isofate_ternary.py" for a ternary mixture of hydrogen, deuterium, and helium. "constants.py," "isofunks.py," and "orbit_params.py" contain physical constants and supporting functions required to run the main isofate_.py scripts.