The equation of motion for a charge in an electromagnetic field is wri
tten in the Fermi coordinates of an observer moving with a constant ac
celeration g = 9.8 m/s(2)(10(-18) cm(-1) in units such that c = 1). Th
is is involved in the equation of motion not only as a Newtonian term
($) over right arrow g, but also as a relativistic correction of the f
orm ''-2(($) over right arrow g .($) over right arrow v)($) over right
arrow v.'' We have studied the effect of this term under the conditio
ns of an accelerator of particles. To this end, we have considered a c
onstant and uniform magnetic field, and a periodic electric field, bot
h directed along the vertical direction. When the frequency of the ele
ctric held is taken to be equal to the Larmor frequency of the charge
in the magnetic field, a resonant effect occurs, producing a secular h
orizontal drift of the nearly circular trajectory.