Growth of nanoparticles in dynamic plasma.

Coagulation growth kinetics of nanoparticles in plasma is affected by interparticle electrostatic forces due to the charging phenomenon. In stationary plasmas, unipolar charging of particles results in retardation of particle growth and may result in a limitation on particle size. We demonstrate the opposite effect of enhanced particle growth in atmospheric pressure nonstationary arc discharge.

Determining the gas composition for the growth of BNNTs using a thermodynamic approach.

High-yield production of high-quality boron-nitride nanotubes (BNNTs) has been reported recently in several publications. A boron-rich material is evaporated using a laser or plasma in a nitrogen-rich atmosphere to supply precursor gaseous species for nucleation and growth of BNNTs. Either hydrogen was added or pressure was increased in the system to achieve high yield and high purity of the synthesized nanotubes.

Using Laser-Induced Rydberg Spectroscopy diagnostic for direct measurements of the local electric field in the edge region of NSTX/NSTX-U: Modeling.

We discuss a novel diagnostic allowing direct measurements of the local electric field in the edge region of NSTX/NSTX-U. This laser based diagnostic's principle consists of depleting the naturally populated = 3 level to a Rydberg state-sensitive to electric fields-that will result in a suppression of part of the emission. We refer to this approach as Laser-Induced Rydberg Spectroscopy.

Spectroscopic study of plasma evolution in runaway nanosecond atmospheric-pressure He discharges.

Time- and space-resolved visible-emission spectroscopy measurements are applied to study plasma parameters in nanosecond electrical discharges in He gas at pressure of 10(5) Pa, using a 150 kV, 5 ns duration high-voltage pulse. The plasma evolution during the discharge is investigated by applying line-shape analysis of several He I spectral transitions, with the Stark and opacity effects accounted for. The analysis shows that the discharge plasma is not in equilibrium and that significant electric fields of several kV/cm are present in the plasma during the discharge.

Coulomb microexplosions of ferroelectric ceramics.

Energetic neutral and extreme ultraviolet emission initiated by the dense plasma propagation along a ferroelectric surface has been found. It was shown that the emission of neutrals is characterized by a large divergence and velocities up to 7 x 10(7) cm/s. This phenomenon is explained by an extremely large electric field with amplitude > or =10(6) V/cm and rise time approximately 10(-10) s which appears at the plasma front due to the fast fall in the driving pulse.