Direct measurement of the rates of nonradiative relaxation processes in electronically excited xenon clusters was carried out. The clusters were created in a pulsed supersonic beam and two-photon excited by femtosecond laser pulses with a wavelength of 263 nm. The measurements were performed using the pump-probe method and electron spectroscopy. It is shown that relaxation of light clusters XeN (N < 15) predominantly occurs by desorption of excited xenon atoms with a characteristic time constant of 3 ps. Heavier electronically excited clusters (N > 10) vibrationally relax to the lowest electronically excited state at a rate of about 0.075 eV/ps. Multiply excited clusters are deactivated via energy exchange between excited centers with the ionization of one of them. The production of electrons in this process occurs with a delay of ∼4 ps from the pump pulse, and the process is completed in 10 ps.
Serdobintsev, P. Y., Melnikov, A. S., Pastor, A. A., Timofeev, N. A., & Khodorkovskiy, M. A. (2018). Relaxation times measurement in single and multiply excited xenon clusters. Journal of Chemical Physics, 148(19). https://doi.org/10.1063/1.5025274