Dissociative Fragmentation of Polyciclic Aromatic Hydrocarbons with 532 nm Laser Radiation

A pulsed supersonic jet of polyaromatic hydrocarbons mixed with noble gases was produced by adiabatic expansion in a high vacuum chamber (2x10$^{-8}$ torr). The PAH's were heated in order to obtain their vapors. The pulsed mixtures interacted at 90\r{ } degrees with the 532 nm laser radiation from second harmonic of a Nd:YAG laser at intensities of 10$^{11}$-10$^{12}$ W$\cdot $cm$^{-2}$. The produced ions from photodissociation-photoionization processes were extracted, accelerated at 3.5 keV and analyzed in a time of flight mass spectrometer. In previous work (1) with 355 nm, only low mass ions were detected. At the present wave length, single charged ions were observed with compositional arrangements of the type C$_{n}$H$_{m}^{+1}$ with 3$