  In this paper, exponential energy-preserving methods are formulated and
analysed for solving charged-particle dynamics in a strong and constant
magnetic field. The resulting method can exactly preserve the energy of the
dynamics. Moreover, it is shown that the magnetic moment of the considered
system is nearly conserved over a long time along this exponential
energy-preserving method, which is proved by using modulated Fourier
expansions. Other properties of the method including symmetry and convergence
are also studied. An illustrated numerical experiment is carried out to
demonstrate the long-time behaviour of the method.
