neoclassics_calc_D11_plateau Function

    function neoclassics_calc_D11_plateau() result(D11_plateau)
        !! Calculates the plateau transport coefficients (D11_star sometimes)
        !
        ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
        use const_and_precisions, only: pi, me_, mp_, c_
        use physics_variables, only: rmajor

        real(dp),dimension(4,no_roots) :: D11_plateau, v
        real(dp),dimension(4) :: mass

        mass = (/me_,mp_*2.0d0,mp_*3.0d0,mp_*4.0d0/)

        v(1,:) = c_ * sqrt(1.0d0-(KT(1,:)/(mass(1) * c_**2)+1)**(-1))
        v(2,:) = c_ * sqrt(1.0d0-(KT(2,:)/(mass(2) * c_**2)+1)**(-1))
        v(3,:) = c_ * sqrt(1.0d0-(KT(3,:)/(mass(3) * c_**2)+1)**(-1))
        v(4,:) = c_ * sqrt(1.0d0-(KT(4,:)/(mass(4) * c_**2)+1)**(-1))

        D11_plateau = pi/4.0 * vd**2 * rmajor/ iota / v

    end function neoclassics_calc_D11_plateau