Industrial Applications of Pulsed Particle Beams and Pulsed Power Technologies

Industrial Applications of Pulsed Particle Beams and Pulsed Power Technologies

Kiyoshi Yatsui, Weihua Jiang, Hisayuki Suematsu, Go Imada, Tsuneo Suzuki, Makoto Hirai, Xiaopeng Zhu

Extreme Energy-Density Research Institute, Nagaoka University of Technology, 1603–1 Kamitomioka, Nagaoka, Niigata 940–2188, Japan

Abstract. In close collaboration with government, municipality and private companies, the systematic studies on pulsed power technology have been carried out at Extreme Energy-Density Research Institute (EDI), Nagaoka University of Technology. In particular, the applications are emphasized to materials science by intense, pulsed ion beam evaporation (IBE) using high-density ablation plasma. Various kinds of thin films or ultrafine nanosized powders have been prepared very efficiently. Additionally, the nanosized powders can be successfully synthesized by pulsed wire discharge (PWD) as well. The industrial applications have also been succeeded in NO_x treatment by an intense, pulsed relativistic electron beam (IREB) or pulsed corona discharge using an inductive-energy-storage (IES) pulsed power generator. Recent progress at EDI will be overviewed.

INTRODUCTION

Extreme Energy-Density State (EEDS), which is a state of extremely high temperature and high density, dose not exists naturally on the earth. However, if EEDS is easily created at the laboratory, new applications such as materials synthesis, short-wavelength light source development and flue-gas treatment can be available.

At Extreme Energy-Density Research Institute (EDI), by using pulsed power technology, the investigations on generation and applications of EEDS have been actively carried out since 1980. Until now, the authors have accomplished preparation of novel materials [1–15], development of pulsed power generators [16–18], flue-gas treatment [16–18] and generation of high-power microwave [19], etc.

In this paper, recent activities on pulsed power technology and its applications will be introduced:

·  Blue-light emission from Si nanosized powders [15];

·  Novel critical temperature resistor of sintered Ni-Fe-O nanosized powders [14];

·  NO_x treatment by intense, pulsed relativistic electron beam (IREB) [16, 17];

·  NO_x treatment by inductive-energy-storage (IES) pulsed power generator [18].

The Si and Ni-Fe-O nanosized powders were successfully synthesized by intense, pulsed ion-beam evaporation (IBE) and pulsed wire discharge (PWD), respectively. Here, the IBE and PWD methods were originally developed at EDI. Furthermore, an intense pulsed relativistic electron beam (IREB) has been utilized to remove a large amount of NO_x, which is produced by electrical power plants or diesel gas engines of automobiles. The flue-gas treatment of NOx gas has been carried out by an inductive-energy-storage (IES) pulsed power generator by use of static induction thyristor (SITy).

BLUE-LIGHT EMISSION FROM Si NANOSIZED POWDERS

A schematic of the experimental setup of thin film preparation by IBE is shown in Figure 1. The left-hand side shows an ion-beam diode chamber, which produces an intense pulsed light ion-beam (LIB), while the right-hand side indicates the chamber to prepare thin films or ultrafine nanosized powders (UNP). The intense pulsed light ion-beam generator «ETIGO-II» was utilized for the generation of the LIB. The intense pulsed ion-beam was extracted from a magnetically insulated diode (MID) with a geometrically focused configuration. The MID consists of an aluminum anode, on which the flashboard (1.5-mm-thick polyethylene) was attached as the ion source, and the cathode with slits to extract the ion beam. The gap distance between the anode and the cathode was typically 10 mm. To achieve geometric focusing of the beam, both the anode and the cathode were shaped as concave structures with the curvature of 160 mm and 150 mm, respectively. The current supplied by the external slow capacitor bank produced a transverse magnetic field (~1 T) between the anode and the cathode, by which the electrons were magnetically insulated. The beams were composed of mainly protons (>75 %) and some carbon ions. Typical experimental conditions were peak accelerating voltage of 1 MV, energy density of ~100 J/cm², pulse width of 50 ns. By the irradiation of the pulsed ion-beam on a solid target, pulsed ablation plasma with density of ~10¹⁹/cm³ and electron temperature of a few eV is produced [20].