SAIP2026

Solar modulation of galactic deuterons related to PAMELA, AMS02 and Voyager 1 observations

9 Jul 2026, 09:50

20m

Lecture Hall C3 (University of the Western Cape)

Oral Presentation Track D - Astrophysics & Space Science Astrophysics & Space Science

Speaker

Ms Innocentia Itumeleng Ramokgaba (1. School of Physical & Chemical Sciences, North-West University, Mmabatho, South Africa. 2. Centre of Space Research, North-west University, Potchefstroom, South Africa.)

Description

The recent observations of galactic deuteron (D) from AMS-02 and Voyager 1 detectors provide interesting surprises to the established paradigm of the secondary origin of galactic D. In this study a comprehensive 3D numerical model is used to simulate the solar modulation of D and protons (p) at the Earth from 2006 to 2014, spanning time frames that include solar maximum activity and the magnetic field reversal epoch. For this purpose, the D local interstellar spectrum is revisited based on the recent Voyager 1 observations below 49.6 MeV/nucleon. Our model includes recent developments in the turbulence and diffusion theory to investigate how the evolution of turbulence in the heliosphere is connected to the observed D and p spectra at the Earth. These modelling results are compared to published D and p spectra and the corresponding D/p ratios made by PAMELA and AMS-02 detectors over the same period. A particular objective is to uncover how the D/p ratio evolves at different rigidities over changing solar activity.