Chaotic ionization of relativistic atom. I

Stochastic ionization of highly excited relativistic hydrogen-like atom in the monochromatic field is considered. A theoretical analysis of chaotic dynamics of relativistic electron based on Chirikov criterion as given. Critical value of the external field is analytically evaluated. It is established that the critical value of the external field for the stochastic ionization of the relativistic atom is less than those for the non-relativistic one. (author)