Oscillations in Plasma III (Dipole Mode)

In a hot cathode discharge tube dipole oscillations having the frequency of \(f_{p}/\sqrt{2}\) were observed without applying external oscillating electric fields, where f _p is the frequency of the plasma electron oscillation. In the presence of a weak magnetic field the dipole oscillation splitted into two oscillations whose frequencies were given by \begin{aligned} f_{\pm}{=}\sqrt{\frac{{f_{p}}^{2}}{2}+\left(\frac{f_{c}}{2}\right)^{2}}{\pm}\frac{f_{c}}{2}, \end{aligned} where f _c is the cyclotron frequency of electron.