Propagation of solar-neutron decay electrons in the interplanetary magnetic field

In solar flares, accelerated ions undergo nuclear interactions in the solar atmosphere. In these interactions high-energy neutrons are produced and emitted into the interplanetary space. In this paper the author will discuss several prominent characteristics of electrons produced by the decay of solar neutrons. Calculations are given which show that solar-neutron decay electrons will bring us unique information on the total amount of produced neutrons. Properties of salar-neutron decay electrons are investigated exhaustively by numerical simulations. After a neutron decays in interplanetary space, the electron trajectory has been traced along the magnetic field, taking the electron pitch angle scattering into account. Our calculations show that these electrons can be detected in a properly prepared electron detector if solar flares occur in a region of solar surface from the central to western limb of the Sun. It is predicted that the electron flux will be enhanced when the interplanetary magnetic field is connected to the Sun at its minimum distance from the solar surface. It is predicted that the energy spectrum of solar neutron decay electrons is significantly peaked at around 400 keV, and as such, the neutron contribution to the spectrum can be easily identified from background electrons and/or directly accelerated electrons in the flares.