  A dynamical theory which incorporates the electron-electron correlations and
the effects of external magnetic fields for an electron escaping from a helium
surface is presented. The degrees of freedom in the calculation of the escape
rate is reduced from $3N$ to 3 as compared with other approach. Explicit
expressions for the escape rate in various situations are obtained. In
particular, in the weak parallel magnetic field limit the tunneling rate has an
exponential dependence quadratic with magnetic field strength and an unusual
exponential increase linear with temperature.
