Decay instability of plasma in crossed fields

In this paper it is shown that in plasma placed in crossed electric and magnetic fields, oscillations are excited with the frequency close to the drift frequencyω ₀ =k _? υ _? . Decay of the oscillations into two other oscillations, for which the selection rulesω ₀ =ω ₂ ?ω ₁ andm ₀=m ₂?m ₁ hold, where the frequencyω ₁ is close to the Langmuir frequency of ions, was observed.