TIME RESPONSE OF PHOTON-STIMULATED DESORPTION OF EXCITED-STATE POTASSIUM ATOMS FROM KCL AND KBR

The time response of excited-state potassium desorption from KCl and KBr was investigated with undulator radiation pulses. It was found that the decay curve of the optical emission from desorbed excited-state potassium atoms consists of two components, and that the fast component is several orders of magnitude faster than the existing results of time response for ground-state alkali atoms. It is suggested that the fast desorption of excited-state alkali atoms may be interpreted in terms of lattice instability due to electronic excitation in the surface layer, while a slow one originates from the thermal instability of surface defects.