Case Report: Investigation of the Time Evolution of Optical Breakdown Plasma During Irradiation of Aqueous Solutions of Fe Nanoparticles

The time sweeps of images of optical breakdown plasma flashes under irradiation of aqueous solutions of Fe nanoparticles with Nd: YAG laser radiation (lambda = 1,064 nm, tau = 10 ns, nu = 10 kHz, epsilon = 2 mJ) are studied. It is shown that the sizes of plasma flares, the plasma glow intensity, and the time to reach the maximum intensity are concentrated around certain values. So, for example, the values of 30 mu m are most typical for the maximum size of flares. The maximum luminescence is usually reached in 3-4 ns. It is found that at initial stage of optical breakdown process the water-vapor boundary moves at typical speed of 11 km/s and have maximum and minimum values at 15 and 4 km/s respectively. It is assumed in this work that such a distribution may be associated with the initiation of breakdown on nanoparticles located in different places of the laser radiation waist.

Automated summary

The study revealed that optical breakdown plasma flashes in aqueous solutions of Fe nanoparticles under Nd: YAG laser radiation exhibit specific characteristics, with the sizes of plasma flares, plasma glow intensity, and time to reach maximum intensity concentrated around certain values. The movement speed and range of the water-vapor boundary at the initial stage of breakdown process also show distinct numerical features.