  The interaction of neutrinos with nucleons in the envelope of a remnant of
collapse with a strong magnetic field during the passage of the main neutrino
flux is investigated. General expressions are derived for the reaction rates
and for the energy-momentum transferred to the medium through the neutrino
scattering by nucleons and in the direct URCA processes. Parameters of the
medium in a strong magnetic field are calculated under the condition of
quasi-equilibrium with neutrinos. Numerical estimates are given for the
neutrino mean free paths and for the density of the force acting on the
envelope along the magnetic field. It is shown that in a strong toroidal
magnetic field, the envelope region partially transparent to neutrinos can
acquire a large angular acceleration on the passage time scales of the main
neutrino flux.
