Research on Electromagnetic Plasma Acceleration. Volume II. An Investigation of the Various Plasma Discharges Surrounding a Solenoidal Coil Excited with Current at 4 Megacycles

摘要

Various discharges which occur surrounding a shielded solenoidal coil excited with current at 4 megacycles are examined for the gases helium, nitrogen, neon, argon, krypton, and xenon in the pressure range 0.02 to 0.50 Torr. Measurements are made of various electrical properties including the operating power and the resistance and inductance reflected into the driving circuit by the discharges. A limited amount of optical spectrographic data was obtained. Microwave measurements were also made for selected conditions. A total of twelve modes of operation of the discharges were observed including Bright and Dim modes. Discharges occur both inside the solenoidal coil and in the space surrounding it. The two types appear to be independent in the sense that they can occur alone or in concert. Various types of fine structure were observed including rings of highly luminous balls of plasma located around the outside of the coil. Power levels up to 4000 watts were used. The values of reflected resistance behave in a manner inconsistent with the observed changes of inductance when correlated through the medium of theory. The values of resistance exhibit only slight dependence on pressure and current except near threshold of the various modes. The maximum change in resistance with type of gas was a factor of two. (Author)