Using semiclassical closed orbit theory, we analyze the chaotic phenomena of the classical trajectories of an electron in strong electric and magnetic fields.

In electron storage ring, the distortion of closed orbit and dispersion, due to inaccuracies of magnets manufacture and misalignment, will cause a series of negative effects, such as tune-shift, distortion of optic function, decrease of dynamic aperture, and decrease of luminance et al.

This article discusses under what starting conditions a closed orbit can be obtained with-in the circular orbit in elastic force-field when the mass point df motion is acted on by theradial perturbation.

By integrating the Hamiltonian caonical equation,we calculate all the closed orbits with d=2 000,n=25.

By using the classical Hamilton canonicl equation,the semiclassical closed orbits are obtained,which make it possible to calculate the molecular recurrence spectra.

It is shown that for a particle with suitable angular momenta in the screened Coulomb potential or isotropic harmonic potential, there still exists closed orbits rather than ellipse, characterized by the conserved perihelion and aphelion vectors, i.