ИСТИНА

A Dusty Plasma in a Non-Self-Sustained Gas Discharge at Atmospheric Pressure A.V. Filippov, V.N. Babichev, A.F. Pal, A.N. Starostin, V.E. Cherkovets SRC RF Troitsk Institute for Innovation and Fusion Research, Troitsk, Moscow, Russia apal@triniti.ru The interest to the dusty plasma under pressures of order of 1 bar has been raised quite recently and is basically connected with studying the possibility of developing autonomous energy sources on the basis of plasma-dusty structures [1]. The operation of such an energy source is based on a non-ideal plasma created by high energy products of radioactive decay of radionuclide fuel which is micron sized dust particles. The non-self-sustained (NSS) gas discharge controlled by an external electron beam appeared to be most suitable tool for experimental modeling of such plasma. Therefore, the present paper reports the results of the experimental and theoretical studying of the dusty plasma excited by a fast electron beam under atmospheric or higher pressures. Experiments were carried out in Ar at atmospheric pressure with injected CeO2 1-5 micron size particles. Gas ionization rate of 115 keV e-beam was about 1014cm-3s-1. The self-consistent model of the NSS discharge from [2] was modified by taking into account the processes of electron and ion losses owing to the sink to dust particles as well as hydrodynamic equations for the neutral gas. The numerical calculations have showed that levitated disk-like structure, observed in experiment are the dusty component in a liquid state, with the modified nonideality parameter [3] decreasing with the growth of the voltage due to the decrease in dusty cloud density. When the applied voltage grows the width of the dusty cloud increases, which leads to the decrease in the particle density in case the total number of particles is constant. The levitation height of the clouds were determined and compared with experiment. Total number of dusty particles in discharge volume depends strongly on their radius. At the given density of dust material, gas ionization rate and applied voltage there is critical radius of dust particles above which all the injected particles were deposited at the cathode. Analytical expressions are obtained for determination of all parameters of the dusty cloud in the NSS gas discharge under uniform volume gas ionization – critical size, theirs charge and number density, depending on gas kind and ionization rate as well as applied voltage. The created analytical theory can be used for estimation of optimal parameters of dusty plasma in the atomic photovoltaic battery. By this means the self-consistent model of the NSS discharge in noble gases reveals how a trap for dust particles forms. The work was supported by the State Atomic Energy Corporation “Rosatom” (contract no. Н.4х.44.90.13.1107) and a grant from the President of the Russian Federation (no. NSh-493.2014.2). References [1] A.V. Filippov, A.F. Pal', A.N. Starostin et al., Ukr. J. Phys., 50, No.2, 137 (2005). [2] A.V. Filippov, V.N. Babichev, N.A. Dyatko et al., JETP, 102, 342 (2006). [3] O.S. Vaulina, S.A. Khrapak, JETP, 90, 287 (2000).