Electric fields in plasmas under pulsed currents

Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for 3D spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously.Comment: 13 pages, 13 figures, submitted to PR

“Electron impact ionization of helium isoelectronic systems"

We show that the criticism [Eur. Phys. J. D 49, 167 (2008)] of our empirical formula for electron-impact ionization of atomic ions [J. Phys B. 33, 5025 (2000)] is unjustified

Use of laser spectroscopy for high-accuracy investigations of relatively-dilute pulsed plasmas with nanosecond time resolution

In this report we describe the development of new approaches to measure the electric field and properties of relatively dilute plasmas under high-power pulses at the nanosecond time scale. These approaches are based on high-resolution laser spectroscopy. The study is carried out in a coaxial-pulsed-plasma configuration. The plasma was doped with a laser-produced lithium beam, followed by pumping of a selected transition in LiI using a tunable dye laser. This setup enables to perform spatially resolved sub-mm measurements of the electric field properties and the plasma parameters. For the first time, line-shape diagnostics with a sub-microsecond resolution was successfully applied to low-density plasma, down to 10 13 cm-3