Patent Number: 047598948
Section: summary

DESCRIPTION 1. Technical Field This invention generally relates to high power electrical discharge apparatus and more specifically to electrical discharge apparatus for producing a transient temperature of at 10 million degrees Kelvin. It also particularly relates to thermonuclear fusion reactors. 2. Background Art It has long been known that the temperature within an electrical discharge is high and that electromagnetic energy is radiated thereby. Many electromagnetic radiation sources (both pulsed and continuous) rely directly upon this effect to generate the desired radiation. Electrical discharges have also been used to produce a high local temperature for heat treatment or for producing a chemical effect. Electric arc welding, for example, is based upon this effect. It is also known that as the temperature of the plasma produced by the discharge increases, the wavelength decreases (assuming the same plasma composition) and the intensity of the radiation increases. The highest temperature heretofore produced with a confined electrical discharge is believed to be reported by S. Zakharov et al in an article entitled "Soft x-ray emission in a high-current capillary discharge," Sov. Tech. Phys. Lett., Vol. 6, No. 9, pages 486-487 (1980). The electron temperature of the plasma was reported to be 150-200 eV, which corresponds to about 2 million degrees Kelvin and produces a radiation in the soft x-ray region. The article suggests that by using a faster rising electrical pulse and a lower impedance transmission line for delivering the electrical pulse, even higher temperatures can be achieved. Analysis reveals that the current flow in the reported configuration was already limited by the discharge rather than by the current delivery apparatus. Accordingly, the current flow and the resulting temperature would not be increased significantly by these improvements. A still higher electrical discharge plasma temperature of 10 million degrees Kelvin or more is desirable because radiation would be produced thereby which is not very easily or economically produced by other methods. Transient ultra-high temperatures in this range also could be used to support or initiate ultra-high temperature chemical reactions which are not possible today. The shock wave produced by such a discharge might be used to induce shock wave chemical reactions. Hard x-ray radiation would be produced by a plasma temperature of 10 million degrees Kelvin or more. At 10 million degrees Kelvin, the temperature is also high enough to allow certain thermonuclear reactions to occur (albeit inefficiently), thereby resulting in liberation of some high energy neutrons. A convenient, portable and inexpensive source of high energy neutrons is not available today. At a plasma temperature of 60 million degrees Kelvin or more, certain thermonuclear reactions could be supported efficiently. A practical method and apparatus for supporting a controlled (i.e., self-extinguishing) thermonuclear fusion reaction (unlike the uncontrolled self-supporting one produced by a fusion bomb) promises cheap, clean and virtually unlimited power generation, and has been sought for decades. A useful thermonuclear fusion reaction rate occurs when a plasma is formed with suitable constituents at a temperature and density which are both suitably high and such conditions are maintained for a sufficiently long time. A plasma temperature of at least 60 million degrees Kelvin is required, which is very difficult to generate. Still more difficult to overcome is the tendency for a plasma having such a high temperature to expand, thereby lowering the plasma density and temperature so much and so quickly that a useful thermonuclear reaction rate (cross section) tends thereby to be avoided. The temperature required is so high that no physical container can withstand such temperature without vaporizing. Early attempts were made to use an electrical discharge to produce a suitably high temperature and to rely upon self-induced magnetic fields to contain the plasma sufficiently to achieve the required density-time product for a useful thermonuclear burn. Such work is reported, for example, in the following articles: R. S. Pease, "Equilibrium Characteristics of a Pinched Gas Discharge Cooled by Bremsstrahlung Radiation", Proc. Phys. Soc., Vol. B70, p.11 (1957); PA0 S.I. Braginskii, "The Behavior of a Completely Ionized Plasma In A Strong Magnetic Field", Soviet Physics JETP, Vol. 6(33), p.494 (1958); PA0 H. Alfven et al, "Gas-Insulation of a Hot Plasma", Nature, Vol. 188, p.801 (Dec. 3, 1960); PA0 C-G. Flathammer, "Stationary State of a High-Temperature Gas-Insulated Plasma Column", Phys. Fluids, Vol. 4, p.1145 (1961); PA0 E. A. Smars et al, "Toroidal High-Pressure Discharge Experiment", Phys. Fluids, Vol. 4, p.1151 (1961); PA0 E. A. Smars, "Experiment on a high-current discharge at a atmospheric pressure", Phys., Vol. 29, p.97 (1964); PA0 L. A. Jones et al, "A laser-initiated, gas-embedded Z Pinch; experiment and computation", Appl. Phys. Lett., Vol. 38, p.522 (1981); All such attempts failed to produce suitable thermonuclear reaction conditions, so attention gradually turned for containment of a thermonuclear plasma to the use of externally generated electrical and/or magnetic fields and/or externally generally beams (laser, ion or electron beams). Past techniques for forming suitable conditions for a controlled thermonuclear fusion reaction have generally relied upon externally generated beams and/or externally generated fields to contain the plasma. Unfortunately, generation of the extreme temperature and pressure required to support a useful thermonuclear fusion reaction using externally generated beams or fields requires so much energy that a net gain in energy from the thermonuclear fusion process has remained elusive. An object of this invention is to produce a controlled thermonuclear fusion reaction without using externally supplied fields or beams to confine the reaction plasma. It is also an object of this invention to produce a useful thermonuclear fusion reaction using an electrical current discharge. Another object is to provide a compact, inexpensive and portable thermonuclear fusion reactor. It is a further object to provide a thermonuclear fusion reactor which produces more useful energy than it requires to operate. Still another object is to provide a convenient compact, portable and inexpensive source of high energy nuclear particles. It is also an object of this invention to provide a source of hard x-ray radiation using an electrical discharge. A further object is to provide suitable conditions for ultra-high temperature chemical reactions and for shock wave chemistry. Another object is to produce a transient temperature of at least 10 million degrees Kelvin and preferably at least 60 million degrees Kelvin with an electrical discharge.