COVARIANCE IMAGES OF THE PRIMARY RESPONSE FROM RARE-GAS CLUSTER IONS TO PHOTOEXCITATION

The photoexcitation and fragmentation of rare gas cluster ions can yie ld large numbers of neutral products which, in turn, exhibit considera ble variation in their kinetic energies. In order to interpret such ev ents, a coincidence technique has been used to correlate the arrival t imes of neutral photofragments at a detector following the photoexcita tion of Ar-n(+) and Kr-n(+), for n less than or equal to 10. By collec ting data from approximately 10(5) photodissociation events for each t ype of cluster ion, covariance images have been derived which clearly demonstrate that the initial response to photoexcitation, is the eject ion of a single rare gas atom which carries with it between 30% and 60 % of the excess energy. (C) 1997 American Institute of Physics.