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A review of mainly the past two years is undertaken of the industrial applications of pulsed power. Repetitively operated pulsed power generators with a moderate peak power have been developed for industrial applications. These generators are reliable and have low maintenance. Development of the pulsed power generators helps promote industrial applications of pulsed power for such things as food processing, medical treatment, water treatment, exhaust gas treatment, ozone generation, engine ignition, ion implantation and others. Here, industrial applications of pulsed power are classified by application for biological effects, for pulsed streamer discharges in gases, for pulsed discharges in liquid or liquidmixture, and for material processing.Index Terms -Pulsed power, industrial application, bioelectrics, exhaust gas treatment, discharge in liquid, material processing.

A pulsed discharge produced underwater has been an attractive method to treat waste water. For the optimization and realization of the water treatment system utilizing underwater pulsed discharge, modeling analysis could be one of the essential works. However, there is still no simulation work about the underwater pulsed discharge due to the lack of knowledge about its characteristic parameters such as electron temperature, electron density, and so on. In this paper, the temperature and the electron density in a pulsed discharge plasma produced underwater are measured and presented. A magnetic pulse compressor (MPC) was developed and used to create the electrical discharge in water. The developed MPC is all-solid state and is, therefore, a maintenance-free generator. To define the temperature and the electron density in an underwater pulsed discharge plasma, two kinds of spectroscopic measurements, called the line-pair method and Stark broadening, were carried out. According to the experimental results, the temperature and the electron density in the pulsed discharge plasma between point-plane electrodes immersed in water are determined to be 15 000 K and 10 18 /cm 3 , respectively.

Nanosecond pulsed streamer discharge has unique characteristics that differentiate it from longer discharges. The very fast voltage rise time, peak voltage plateau, short pulse duration, and fast fall time enable a large volume of uniform nonthermal plasma generation at atmospheric pressure. This review explains the physics of nanosecond discharge plasma through experimental and simulated studies for plasma processing techniques. The following are discussed and compared between sub-microsecond and nanosecond discharge plasma: discharge phase transition, discharge propagation, production of chemically active species, temperature change of gas during plasma propagation, electrode geometry, effect of voltage rise rate, voltage polarities, and N 2 /O 2 gas composition ratio in air seeding gas. Nanosecond pulse discharge plasma is characterized by a considerably faster streamer head propagation velocity and reduced gas heating, resulting in a higher energy efficiency for plasma processing. Ozone generation, nitric oxide treatment and volatile organic compound treatment results are given as examples of plasma processing.

A Blumlein generator that has a pulsewidth of 100 ns was used to investigate the process of streamer discharge propagation in a coaxial cylindrical reactor using a streak camera. Both positive and negative polarities of the streamer discharges were performed in air at atmospheric pressure. The results showed that the primary and secondary streamers propagated with increasing velocity from the central rod to the outer cylinder electrode in both positive and negative polarities of applied voltages to the rod electrode. The propagation velocity of the streamer heads was in the range of 0.8-1.2 mm/ns for a positive peak applied voltage in the range of 43-60 kV and 0.6 mm/ns for a negative peak applied voltage of −93 kV, respectively. The electric field at streamer onset was calculated to be 12 and 20 MV/m for positive and negative applied voltages, respectively.Index Terms-Atmospheric pressure air, coaxial electrode, electric field, nanosecond pulse, propagation velocity, pulsed streamer discharge, streamer onset.