M. J. Boschini, S. Della Torre, M. Gervasi, D. Grandi, G. Johannesson, G. La Vacca, N. Masi, I. V. Moskalenko, S. Pensotti, T. A. Porter, L. Quadrani, P. G. Rancoita, D. Rozza, M. Tacconi

Since its launch, the Alpha Magnetic Spectrometer-02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species, $e^{\pm}$, $\bar{p}$, and nuclei (H-Si, S, Fe), which have resulted in a number of breakthroughs. Besides elemental spectra, AMS-02 also measures the spectra of light isotopes albeit within a smaller rigidity range. In this paper, we use the precise measurements of He isotopes and the $^3$He/$^4$He ratio by AMS-02, together with Voyager 1 data, and investigate their origin. We show that there is an excess in $^3$He at higher energies compared to standard calculations assuming its fully secondary origin, which may indicate a source of primary $^3$He, or signify a change in the propagation parameters over the Galactic volume probed by the $^3$He/$^4$He ratio. We provide updated local interstellar spectra (LIS) of $^3$He and $^4$He in the rigidity range from 2-40 GV. Our calculations employ the self-consistent GalProp-HelMod framework that has proved to be a reliable tool in deriving the LIS of CR $e^{-}$, $\bar{p}$, and nuclei $Z\le28$.