f_eff (Eq. (17)) as a function of heliocentric distances for two values of R_max for my toy parameterization of the particle flux distribution (see end of Sect. 2.2) and two values of the radial Schmidt number, with the lower one (higher relative diffusivity) in dotted lines. The parameter f_eff is proportional to the ¹⁰Be/⁹Be ratio (whose absolute magnitude is discussed at Eq. (22)) in the bulk (gas+solids) disk for given mass accretion rate and proton output and energy distributions.