Neutronics models the steady-state neutron flux in a reactor. This leads to a generalized eigenvalue problem based on the Boltzmann operator. The neutronics code APOLLO3® is a joint project of CEA, Framatome, and EDF for the development of a next-generation code for reactor core physics to meet both R& D and industrial application needs. The Minaret solver [2] is developed within the framework of the APOLLO3® project. This solver is based on a discontinuous finite element discretization of the neutron transport model. The strategy for solving the aforementioned generalized eigenvalue problem is iterative; it involves applying the inverse power method. The convergence speed of this inverse power method algorithm depends on the spectral gap. In the context of large cores, it is observed that the spectral gap is close to 1, which degrades the convergence of the inverse power method algorithm. It is necessary to apply acceleration techniques to reduce the number of iterations [4]. In neutron transport, the preconditioning called Diffusion Synthetic Acceleration is very popular for the so-called inner iteration but has also recently been applied to the so-called outer iteration [1]. A variant of this method was introduced in [3] for solving a source problem. It is theoretically shown that this variant converges in all physical regimes. In this talk, we will show numerical results related to the application of a DSA approach onto the so-called outer iteration in the MINARET solver. REFERENCES [1] A. Calloo, R. Le Tellier, and D. Couyras. Anderson acceleration and linear diffusion for accelerating the k-eigenvalue problem for the transport equation. Annals of Nuclear Energy, 180:109406, 2023. [2] J.-J. Lautard and J.-Y. Moller. Minaret, a determininistic neutron transport solver for nuclear core calculations. In M& C, Rio de Janeiro, 2011. [3] O. Palii, M. Schlottbom, On a convergent DSA preconditioned source iteration for a DGFEM method for radiative transfer, Computers & Mathematics with Applications, Volume 79, Issue 12, 2020. [4] J. Willert, H. Park, and D. A. Knoll. A comparison of acceleration methods for solving the neutron transport k-eigenvalue problem. Journal of Computational Physics, 2014, vol. 274, p. 681-694.