  Aims: Investigate/Study de-charging of solar wind C, N, O, Mg, Si and S ions
and assess fluxes of resulting ENA in the heliosphere. Methods: The model
treats the heavy ions as test particles convected by (and in a particular case
also diffusing through) a hydrodynamically calculated background plasma flow,
from 1 AU to the termination shock (TS), to heliosheath (HS) and finally to
heliospheric tail (HT). The ions undergo radiative and dielectronic
recombinations, charge exchanges, photo- and electron impact ionizations with
plasma particles, interstellar neutral atoms (calculated on a Monte-Carlo
model) and solar photons. Results: Highly-charged heavy coronal ions flowing
with the solar wind undergo successive de-ionizations, mainly in the
heliosheath, leading to charge-states much lower than in the supersonic solar
wind. If Coulomb scattering is the main ion energy loss mechanism, the end
product of these deionizations are fluxes of ENA of ~1 keV/nucleon originating
in the upwind heliosheath that for C, Mg, Si and S may constitute sources of
pickup ions (PUI) significantly exceeding the interstellar supply. Conclusions:
Discussed processes result in (i) distinct difference of ion charge q in the
supersonic solar wind (approximately q >= +Z/2, Z = atomic number) compared to
that in the HS (approximately 0 <= q <= +Z/2)), (ii) probable concentration of
singly ionized atoms (q = +1) in the heliosheath towards the heliopause (HP)
and in the HT, (iii) possible significant production of ENA in the HS offering
natural explanation for production of PUI, and -- after acceleration at the TS
-- anomalous cosmic rays (ACR) of species (like C, Mg, Si, S) unable to enter
the heliospheric cavity from outside because of their total ionization in the
local interstellar medium.
