An optoacoustic study and simulation of the optical properties of cyclotrimethylenetrinitramine–ultrafine nickel particle composites

Optoacoustic signals induced by pulsed laser radiation (pulse width at half maximum 14 ns) with a wavelength of 532 nm are experimentally obtained in pressed cyclotrimethylenetrinitramine (RDX)–ultrafine nickel particle composites, and the observed parameters of radiation absorption at average particle radii of 40, 60, 80, and 140 nm are determined. It is shown that the dependence of the experimental absorption index on the particle radius with a constant mass fraction is a nonmonotonic function. The results are interpreted within the framework of the theory of monochromatic radiation transfer. It is shown that the agreement between the experimental and calculated absorption index values of pressed RDX–ultrafine nickel particle tablets with different radii is achieved when the residual porosity of the sample is taken into account. The mean pore radius and the concentration of pores are estimated.