episciences.org_15867_2026051822204212620260518222042126episciences.orgraphael.tournoy+crossrefapi@ccsd.cnrs.frepisciences.orgOpen Plasma Science3076-146810.46298/journals/opshttp://ops.episciences.org01142026Volume 1PeterDonnelInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0000-0002-6669-416XKevinObrejanInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMYanickSarazinInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0000-0003-2479-563XRoméoBiguéInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMPhysique des interactions ioniques et moléculairesEmilyBourneEcole Polytechnique Fédérale de Lausannehttps://ror.org/02s376052EPFLhttps://orcid.org/0000-0002-3469-2338GuillaumeBrochardInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0000-0002-3208-3651Ludovicade GianniInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMGuilhemDif-PradalierInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0000-0003-4869-7049XavierGarbetInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMNanyang Technological University [Singapour]https://ror.org/02e7b5302NTUhttps://orcid.org/0000-0001-5730-1259VirginieGrandgirardInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0000-0001-7821-9107PhilippKrahInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMYannMunschyInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMProtaisMatthieuInstitut de Recherche sur la Fusion par confinement Magnétiquehttps://ror.org/03hffat62IRFMhttps://orcid.org/0009-0003-5852-7446Gyrokinetic codes are used to simulate transport in tokamak plasmas. In these codes, the distribution functions evolve self consistently with an electromagnetic field. To compute the temporal evolution of the electrostatic potential, a quasi-neutrality equation is solved. In some gyrokinetic codes, the quasi-neutrality solver assumes that the background densities and temperatures are constant in time and on flux surfaces. This assumption, which implicitly uses the so-called δF approach, can break up, in particular at the edge of the plasma which can display large and time evolving poloidal asymmetries.In this paper, a numerical solver of the quasi-neutrality equation accounting for time evolving poloidal asymmetries is presented. This solver is compatible with all electron models (adiabatic, kinetic or hybrid) and written for the long wavelength or the Padé approximations for the polarisation term. The impact of such an improvement is carefully reported on different types of simulations, illustrating when the δF approach forquasi-neutrality is valid and when it fails. A procedure to limit the numerical cost of updating the background profiles in the quasi-neutrality solver is also presented.011420261203202515867European Commission101052200https://creativecommons.org/licenses/by/4.0https://creativecommons.org/licenses/by/4.0https://creativecommons.org/licenses/by/4.0https://hal.science/hal-05111064v3https://hal.science/hal-05111064v2https://hal.science/hal-05111064v110.46298/ops.15867http://ops.episciences.org/15867https://hal.science/hal-05111064v3/documenthttps://hal.science/hal-05111064v3/document