High Current, Metal Vapor Vacuum Arc (mevva) Ion Source

Abstract

A Metal Vapor Vacuum Arc (MEVVA) which has been operated at currents from 4 to 68 kA and current densities up to 24 kA/cm{sup 2} is under study at Science Research Laboratory (SRL). The MEVVA plasma is formed by drawing a low-voltage (< 2 kV) arc from a metal cathode to a transparent anode. A dense, highly ionized and nearly current free plasma streams past the anode and is confined and guided in a magnetic field. The SRL MEVVA is under development as a high density (n{sub i} {approximately} 10{sup 16} cm{sup {minus}3}) plasma source for use as imploding loads on high current, z-pinch x-ray simulators. The density of the MEVVA plasma has been measured to be {approximately} 10{sup 15} cm{sup {minus}3} in Ti and Cu ion plasmas with current densities at the cathode of {approximately} 10 kA/cm{sup 2}. Studies of discharges at higher current densities are presently under way. Data presenting the scaling of the ion density and total ion production with the discharge current over a wide range of currents will be presented. As a possible method to increase the plasma density, the effects of guiding the plasma into a converging magnetic nozzle are being studied. The resultsmore » of these experiments will be presented as well as data on the confinement of a non-converging magnetic field.« less