Comment on "On the spatial and temporal resolution of ion temperature measurements based on neutral beam scattering"

The discrepancies found by Donné and Barbian [A. J. H. Donné and E. P. Barbian, Rev. Sci. Instrum. 58 (1987)] can be attributed principally to the choice of experimental and technical limits, basic assumptions, and definitions

Hot biogas conditioning using pulsed corona

A new technology area for pulsed corona is hot biogas cleaning, important in view of the growing interest in biomass gasification. Our work concentrates on the development and optimization of pulsed electrical methods for treatment of thermally generated biogas. Corona energized by narrow voltage pulses (100 kV) makes a well ordered and concentrated deposition possible of electrical energy from a circuit into a hot polluted gas. The created plasmas can break down various contaminants. Successful introduction of pulsed corona for industrial processes very much depends on the reliability of high-voltage and pulsed power technology and on the efficiency of energy transfer. In addition, we must achieve adequate electromagnetic compatibility (EMC)

Numerical and experimental investigation of dielectric recovery in super-critical nitrogen

A supercritical (SC) nitrogen (N2) switch is designed and tested. The dielectric strength and recovery rate of the SC switch are investigated by experiments. In order to theoretically study the discharge and recovery process of the SC N2 switch under high repetition rate operation, a numerical model is developed. For SC N2 with initial parameters of p = 80.9 bar and T = 300 K, the simulation results show that within several nanoseconds after the streamer bridges the switch gap, the spark is fully developed and this time depends on the applied electric field between electrodes. During the whole discharge process, the maximum temperature in the channel is about 20 000 K. About 10μs after the spark excitation of 200 ns duration, the temperature on the axis decays to Taxis 1500 K, mainly contributed by the gas expansion and heat transfer mechanisms. After 100μs, the dielectric strength of the gap recovers to above half of the cold breakdown voltage due to the temperature decay in the channel. Both experimental and numerical investigations indicate that supercritical fluid is a good insulating medium that has a proved high breakdown voltage and fast recovery speed