Multistep photoionization of dye vapors

Results are given of observations of intense multistep photoionization of POPOP, paraterphenyl, and naphthalene molecules pumped by a pulsed continuous-spectrum light source. Investigations were made of the dependence of the photocurrent on the temperature of the cell containing a substance and on the intensity and spectral composition of the pump radiation. Estimates were made of the position of the triplet level of the paraterphenyl and naphthalene molecules in the gaseous phase. Results are presented of a study of the ionization of excited singlet states of the paraterphenyl molecule by λ =266 nm laser radiation.