Non-ambipolr electron extraction from a weakly magnetized RF plasma

Summary form only given. Electron extraction at electron sheaths (i.e. positive going anode sheaths) is studied in weakly magnetized RF inductive plasmas. As with DC plasmas produced with hot filaments, it is shown that all of the electrons created by ionization in the plasma can be extracted from the plasma. The electrons are extracted through a grounded ring and in the presence of a weak axial magnetic field, only a small fraction of the electrons are lost to the ring. All of the ions are lost to a negatively biased conducting cylinder which also serves as a Faraday shield for the RF. Experiments are reported with argon and xenon plasmas having densities of 10¹¹ cm^-3 to 10 ¹² cm^-3. Magnetic fields were as high as 100 gauss at the extraction ring. Extracted electron currents were as high as 4 A. The necessary condition for all of the electrons to be extracted is that the area ratio between the ion loss area and the electron loss area is at least m_em_iY, where m_i is the ion mass and m_e is the electron mass. The bias on the ion cylinder is chosen so that the biased boundary is much more negative than the floating potential, so that electron losses to the boundary can be neglected