  A rapid and relatively simple scheme of calculation is elaborated and applied
to cosmological recombination of helium. Employing the nonrelativistic Coulomb
Green's function, a wavefunction of a colliding electron is represented in an
integral form applicable for calculations. Bound electrons of helium are
described by the Hartree-Fock wavefunctions. The free-bound transition
probabilities into excited states of helium, and the probabilities of
bound-bound transitions in helium are calculated in different modes. It is
revealed that free-bound transition probabilities weakly depend on to what
extent a field experienced by a colliding electron deviates from the purely
Coulomb field with charge Z=1, whereas these probabilities strongly depend on
the choice of a wavefunction of a bound active electron involved in
recombination.
