  The problem of the magnitude of the S--factor of the hep process $p +
{^3\mathrm{He}} \to {^4\mathrm{He}} + e^+ + \nu_e$ is one of the most important
unsolved problems in nuclear astrophysics. The magnitude of $S(hep)$ has also
an important impact on the interpretation of the Super-Kamiokande solar
neutrino results in terms of neutrino oscillations. We point out the possiblity
to determine the major hadronic contribution to $S(hep)$ from the measurement
of the total cross section of the process $n + {^3\mathrm{H}} \to
{^4\mathrm{He}} + e^- + \bar{\nu}_e$ in experiments with high intensity beams
of thermal or cold neutrons.
