A numerical verification of the prediction of an exponential velocity spectrum for a gas of particles in a time-dependent potential well

Abstract

Using computer simulations we demonstrate that, as predicted by Jarzynski and Swiatecki, the velocity distribution f( ν) for a gas of independent particles bouncing around chaotically in several types of deforming containers tends to an exponential function of ν. The generalized one-body dissipation formula for the heating up of such a gas, also derived by Jarzynski and Swiatecki, is shown to give a good overall account of the numerical results, although small deviations are apparent.