Lifetime enhancement of ZEKE states in molecular clusters and cluster fragmentation products with programmed electric pulses

A new control scheme of fast switching of electric pulses is applied to Ryd berg states of the benzene.Ar complex producing highly stable long lived ZE KE states. Since this scheme permits complete external control of the produ ction of ZEKE states it no longer depends on internal experimental paramete rs but can be applied to a much broader range of experiments where such par ameters are often difficult to control such as synchrotron radiation experi ments. This method can even be applied for excitation of the ionic core far above the ionization limit, where these states even survive core fragmenta tion and can be further stabilized by fast electric pulses. (C) 2000 Elsevi er Science B.V. All rights reserved.