Emission spectra of the species ablated from a solid target submerged in liquid: vibrational temperature of C2 molecules in water-confined geometry

Emission spectra of C2 molecules produced at the water–graphite interface by pulsed laser irradiation were obtained at various delay times from the irradiation. Vibrational temperature was determined by the Boltzmann plot based on the vibrational bands in Δν=−1 branch of the Swan system. The results show that it was ca. 5000 K and did not change significantly with the delay time. With increasing the delay time up to ca. 500 ns the signal from the Swan band disappeared before the decrease of the vibrational temperature. The results were explained by the formation of a gas cavity and its collapse at several hundreds of nanoseconds from the laser pulse.