Observation of Laser Radiation Scattering Effects in Explosion Products of Thin Molybdenum Wires

Results of laser probing of products of electrical explosion of thin molybdenum wires in air (20 kV, 10 kA, 350 ns) are presented. Shadow and interferometric images of the discharge gap were obtained simultaneously using probing radiation at two wavelengths (lambda(1) = 1064 nm and lambda(2) = 532 nm). Comparison of images revealed that an increase in the probing wavelength results in substantial increase in transparency of the so-called core, the most long-lived and relatively dense remnants of the wire material, at a relatively late stage of expansion (one microsecond and more after beginning of current). These observations can be explained if we consider that the core material to a large extent consists of small, on the order of one hundred nanometers, particles, scattering from which obeys the Rayleigh dependence on wavelength (similar to lambda(-4)). Presented results show that scattering should certainly be taken into account when analyzing the data of shadow and interferometric probing in studies of electrical explosion of wires.

Automated summary

This study presents the results of laser probing of products of electrical explosion of thin molybdenum wires in air. It is found that increasing the probing wavelength results in a substantial increase in the transparency of the core, which is composed of small particles and scattering from these particles follows a lambda(-4) dependence on wavelength.