A type of explosive driven generator, called a plate generator, is described. It is capable of delivering electrical energies in the MJ range at TW power levels. Plane wave detonated explosive systems accelerate two large-area metal plates to high opposing velocities. An initial magnetic field is compressed and the flux transferred to an external load. The characteristics of the plate generator are described and compared with those of other types of generators. Methods of load matching are discussed. The results of several high-power experiments are also given.
While the basic operating principles of Helical Magnetic Flux Compression Generators are easy to understand, the details of their construction and performance limits have been described only in government reports, many of them classified. Conferences in the field of flux compression are also dominated by contributions from government (US and foreign) laboratories. And the government-sponsored research has usually been concerned with very large generators with explosive charges that require elaborate facilities and safety arrangements. This book emphasizes research into small generators (less than 500 grams of high explosives) and explains in detail the physical fundamentals, construction details, and parameter-variation effects related to them.
A discussion of explosive pulsed power systems and their applications, this book consists of 7 chapters. The first five describe the basic physics of these sources and their ancillary equipment, based on a manual for training engineers in Russia. Chapter 6 is a description of codes and methodologies used at Loughborough University in the UK to build flux compressors, while Chapter 7 covers two specific applications: high power lasers and high power microwave sources. The book introduces all types of explosive power sources and their ancillary equipment, the procedures required to build them, and specific applications.
A survey is made of applications where explosive-driven magnetic flux compression generators have been or can be used to directly power devices that produce dense plasmas. Representative examples are discussed that are specific to the theta pinch, the plasma gun, the dense plasma focus and the Z pinch. These examples are used to illustrate the high energy and power capabilities of explosive generators. An application employing a rocket-borne, generator-powered plasma gun emphasizes the size and weight potential of flux compression power supplies. Recent results from a local effort to drive a dense plasma focus are provided. Imploding liners ae discussed in the context of both the theta and Z pinches.
Explosive pulsed power generators are devices that either convert the chemical energy stored in explosives into electrical energy or use the shock waves generated by explosives to release energy stored in ferroelectric and ferromagnetic materials. The objective of this book is to acquaint the reader with the principles of operation of explosive generators and to provide details on how to design, build, and test three types of generators: flux compression, ferroelectric, and ferromagnetic generators, which are the most developed and the most near term for practical applications. Containing a considerable amount of new experimental data that has been collected by the authors, this is the first book that treats all three types of explosive pulsed power generators. In addition, there is a brief introduction to a fourth type ix explosive generator called a moving magnet generator. As practical applications for these generators evolve, students, scientists, and engineers will have access to the results of a considerable body of experience gained by almost 10 years of intense research and development by the authors.
Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for high-voltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially- detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute another approach that complements the fundamental size, weight, and configuration of the small helical flux compressor. In this paper, we consider first a basic inductive store/opening switch circuit and the implications associated with, specifically, a fuse opening switch and an FCG energy source. We develop a general solution to a transformer/opening switch circuit--which also includes (as a special case) the direct inductive store/opening switch circuit (without transformer) and we report results of one elementary experiment demonstrating the feasibility of the approach. 9 figs.
Magnetic Flux Compression, as treated in this paper, is accomplished by high explosives. Flux is first captured in a closed conducting circuit, of which some or all of the conducting elements are overlaid with high explosives. Upon detonation of the explosives, these elements are driven in such a fashion as to compress the flux into regions of smaller areas or, in engineering terminology, into regions of lower inductance. The magnetic energy associated with the flux is increased by the flux compression. The additional energy is ultimately supplied by the explosive as it drives the conductors against the magnetic field pressure, which in some cases may be in the megabar range. Various names in common use for flux compression devices are flux compression generators (FCG), magneto-cumulative generators (MCG), particularly in the USSR, or simply, flux compressors. FCGs are generally used in two broadly defined categories: as compact, high-power sources to drive various loads: and as generators of very large magnetic fields. In this talk, general principles of flux compression are first discussed. This is followed by a description of several applications in which different types of FCGs are used to supply pulsed power to various devices. The talk closes with a discussion of results obtained from a number of experiments done to explore the properties of materials in very large magnetic fields or under nearly isentropic compression. As requested, the work reported here surveys the Los Alamos program. However, sources cited in the bibliography contain much of the extensive literature in the field. Individual papers cited have been selected partly to highlight other groups that have been active in the field. 25 refs., 15 figs.
There are five widely-used classes of explosive-driven flux compression generators. They are the spiral, coaxial, strip, plate and cylindrical implosion systems. The configurations are described and the characteristics of the various types are compared. There are a number of techniques for sharpening or impedance-matching the output pulse of the generators. The use of switching, fuses and transformers are discussed. Some of the areas of application of the generators are outlined briefly. Much of the recent work at Los Alamos has been directed toward the development of the plate generator. This type consists essentially of a transmission line with explosive slabs on the flat surfaces. These plates may be parallel or at an angle with respect to each other. A plane detonation front in the explosive allows a large area of conductor to be driven simultaneously. As a result, the power and current outputs are very high - many megamperes at the terawatt level. This generator is particularly well suited to driving low impedance plasma devices. The results of the plate generator tests are discussed.
