DYNAMICS OF VERY HIGH-MOLECULAR RYDBERG STATES - THE INTRAMOLECULAR PROCESSES

Classical trajectory computations are used to document and examine the purely intramolecular decay dynamics of very high Rydberg states of a n isolated cold molecule. The Hamiltonian is that of an anisotropic io nic core about which the Rydberg electron revolves. The equations of m otion are integrated using action angle variables in order to ensure n umerical stability for many orbits of the electron. Examination of ind ividual trajectories verifies that both ''up'' and ''down'' intramolec ular processes are possible. In these, the electron escapes from the d etection window by a gain or loss of enough energy. Either process occ urs in a diffusive like fashion of many smaller steps, except for a ve ry small fraction of prompt processes. The results for ensembles of tr ajectories are examined in terms of power spectra of the different mod es of motion and in terms of the decay kinetics. More than one time sc ale can be discerned in the intramolecular decay kinetics and the fast er decay occurs on a nanosecond time scale. The fraction of faster dec aying trajectories which exit by an up or a down process does vary wit h the initial energy.