Coulomb Explosion of Powders under Fast Pressure Decrease

A phenomenon of spontaneous expansion of dielectric particles with a decrease in pressure in a vacuum chamber is experimentally studied. There is a certain range of ambient pressure and pressure decreasing rate at which the phenomenon is observed. The experiments show that the phenomenon relates weakly to gas dynamics, influence of wall material and particle surface desorption. It is established that the Coulomb repulsion of charged particles causes this effect.