Physics Of ICF Related Multiwire Array Implosion

At the present time an investigation into the process of current-driven implosion of cylindrical tungsten wire arrays is under way as applied to the ICF research The investigations performed at the Angara-5-1 facility have shown that after first several nanoseconds of current flowing plasma is generated on the surface of a wire and the current from the wire is switched to the plasma corona. The system includes low density plasma and a dense core. The core keeps its initial position for a significant period of the liner pulse duration and serves as a stationary plasma source. The plasma being continuously generated is accelerated to the liner axis by Ampere's force. This plasma is considerably thick and transfers some fraction of the current. For a better understanding of physics of the wire array implosion process of great interest are investigations into the spatial mass and current distributions inside the array during this process. The current work deals with these investigations performed at the Angara-5-1 facility and presented in three sections: current distribution inside the array during implosion, plasma density distribution during implosion using a method of X-ray probing, electron density distribution during stagnation using a laser interferometer

Gated pinhole camera imaging of the high-energy ions emitted by a discharge produced Sn plasma for extreme ultraviolet generation

The origin and nature of the high-energy ions emitted by a discharge produced plasma source are studied using gated pinhole camera imaging. Time-of-flight analysis in combination with Faraday cup measurements enables characterization of the high-velocity component of the ionic debris. The use of an optional magnetic field allows mass-to-charge analysis of the first part of the Faraday cup signal. It is shown that this consists mainly of oxygen ions emitted from a region near the cathode. Time-resolved images of Sn ions with a kinetic energy of 45 keV visualize the regions in between the electrodes where the high-energy ion generation takes place. © 2009 American Institute of Physics

Characterization of ion emission of an extreme ultraviolet generating discharge produced Sn plasma

The ion emission of a Sn-based discharge produced extreme ultraviolet producing plasma is characterized with the combined use of different time-of-flight techniques. An electrostatic ion spectrometer is employed to measure the average charge distribution of the emitted Sn ions. A dedicated Faraday cup configuration is used to measure the total ion flux from the source for different discharge energies. High-energy Sn ions emitted by the plasma with energies up to 100 keV have been identified. The number of high-energy ions increases for higher electrical input energy into the plasma while the signal associated with the expanding plasma ions does not show such dependence. The ion energy distribution for a bulk of detected ions is calculated based on the Faraday cup measurements and compared with theoretical plasma expansion dynamics