We report on studies of multiple ionization and fragmentation of free Hg n (n ≤ 80) clusters in the femtosecond time domain at wavelengths ranging from 255 nm to 800 nm. After excitation by single laser pulses of an intensity of 5 * 10 11 W/cm 2 we observe prompt formation of multiply charged Hg n clusters. The Hg n cluster size distribution observed up to n ≈ 80 shows in additon to singly charged also doubly and triply charged clusters with a surprisingly high amount of doubly charged clusters. The measured cluster size distribution is nearly independent of laser wavelengths. For higher laser intensities (2 * 10 12 W/cm 2 ) we observe multiply charged mercury atoms up to Hg 5+ . At 10 13 W/cm 2 molecules and clusters eventually disappear due to Coulomb explosion and complete Fragmentation. Only atomic ions, singly and multiply charged, with high kinetic energies are then observed.

313 76.3 77 62. ~L V : 313 763 96 94, 220602 Minsk, Belarris, phone: 375-I72 68 40 61, fa: 375-I72 39 .?I 31.Combination of single niolecule spectroscopy aiid optically detected electron spin resonance (ODESR) is a seiisitivt nietliod to observe an individual spin and to study the triplet state dyriaiiiics of guest niolecules in low-temperature matrices I I I. 111 time-resolved experinients 11 -31 ODESR technique has been applied to investigate