  The secondary electron emission process is essential for the optimal
operation of a wide range of applications, including fusion reactors,
high-energy accelerators, or spacecraft. The process can be influenced and
controlled by the use of a magnetic field. An analytical solution is proposed
to describe the secondary electron emission process in an oblique magnetic
field. It was derived from Monte Carlo simulations. The analytical formula
captures the influence of the magnetic field magnitude and tilt, electron
emission energy, electron reflection on the surface, and electric field
intensity on the secondary emission process. The last two parameters increase
the effective emission while the others act the opposite. The electric field
effect is equivalent to a reduction of the magnetic field tilt. A very good
agreement is shown between the analytical and numerical results for a wide
range of parameters. The analytical solution is a convenient tool for the
theoretical study and design of magnetically assisted applications, providing
realistic input for subsequent simulations.
