rf Plugging of a Plasma by the Ponderomotive Effect on Electrons

Radio-frequency plugging of a streaming plasma was observed in experiments in which the applied electric fields were too weak for plugging by the ponderomotive effect on ions. The experimental parameters met two requirements for the electron ponderomotive effect: (a) the electron thermal speed $v_0\ll \omega L$, the product of the frequency and scale length of the rf field; and (b) the field amplitude $E\gtrsim \left(\frac{2\omega }{e}\right){\left[mk\right(T_e+T_i\left)\right]}^{\frac{1}{2}}$. The plugging observed was the result of the ponderomotive effect on electrons.