AUTHOR=Song Xiaojian , Huo Ran , Xu Songying , Chen Xuemei , Luo Xi 

TITLE=The SDEMMA model for galactic cosmic ray and its dosimetric application

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2025.1383946

DOI=10.3389/fspas.2025.1383946

ISSN=2296-987X

ABSTRACT=IntroductionFuture crewed missions to Mars will encounter substantially elevated radiation levels compared to low Earth orbit operations. To address this challenge, we present the Space-Dependent Energetic cosmic ray Modulation using MAgnetic spectrometer (SDEMMA) model, a novel framework for modeling galactic cosmic ray (GCR) dynamics in deep-space environments.MethodsThe model employs stochastic differential equations with outer boundary conditions derived from contemporary local interstellar spectrum models. Time-dependent diffusion and drift coefficients were optimized through Markov Chain Monte Carlo parameter fitting against 2006-2019 observational data from the space-borne magnetic spectrometers of AMS-02 and PAMELA.ResultsSDEMMA extends GCR spectral calculations to radial positions beyond 1.0 AU, explicitly resolving radial gradients under diverse heliospheric conditions. The framework provides spatiotemporally resolved GCR spectra for charge numbers Z=1–28 at rigidities >0.2 GV, covering the inner heliosphere between Earth and Mars and currently the 2006-2019 epoch.DiscussionImplementation demonstrates the model's operational utility: dose equivalent rates behind 30 g/cm2 polyethylene shielding during a flux minimum range from 14-17 cSv/yr, with variance attributable to quality factor selection.