BEHAVIOR OF D-2 IN AN INTENSE CO2-LASER FIELD

We describe the first investigation of tunnel ionisation and dissociat ion of D-2 in a strong 10 mu m laser field. The process begins with th e single tunnel ionisation of D-2 followed by the subsequent dissociat ion of the molecular ion and is terminated by a second tunnel ionisati on. The fragments' kinetic energy (KE) and ion yields (D-2(+) and D+) were measured as a function of the peak intensity. The KE spectrum has two distinguishable maxima corresponding to slow and fast ions. The e nergy of the slow fragments increases linearly with the laser intensit y, whereas the energy of fast fragments is insensitive to this.