Oscillation spectra of isotropic electron-positron β±-decay plasma

Eigen mode oscillation spectra of an electron-positron plasma are discussed, the plasma being produced by accumulating radioactive isotope β±-decay products. A numerical solution of the corresponding dispersion equations is presented. Analytical relations in the longwave and low damping limits are obtained. In the framework of the initial conditions problem, the longitudinal mode spectrum limitation, closely related to the dielectric index branching points, is analyzed. Special attention is paid to the estimation of the number of transversal modes. 22 refs., 5 figs