LOW-ENERGY ACTIVATION OF SUPERHEATED N-PENTANE BOILING-UP BY LASER PULSE AT THE FIBER-LIQUID INTERFACE

The essence of the present study is to elucidate the possibility of low-energy activation of liquid boiling-up by laser pulses at the solid-liquid interface in a wide range of superheated states. The object of study was n-pentane, uniformly superheated in a miniature bubble chamber. The activation is carried out via a single-mode fiber optic probe having a core diameter of 9-10 mu m. The pulses have a wavelength of 1530 nm and a duration of 2 to 8 ns. Depending on liquid temperature, pulse duration, and the properties of the fiber end, the threshold pulse intensity (energy) required to activate boiling-up varied within a range of 0.01 to 30 MW/cm(2) (0.1 to 300 nJ). The obtained results demonstrate the feasibility of pulsed laser activation of boiling-up using the facilitated laser breakdown mechanism with an accompanying optodynamic impact at the solid/liquid interface. The possibility of reducing the energy required for activating the boiling-up of an initially cold liquid by combining the action of continuous and pulsed laser radiation has been revealed.