Method for producing a shell of relativistic particles at an altitude above the earths surface
United States Patent 5038664
Abstract
A method for establishing a region of a high density, high energy plasma at an altitude of at least about 1500 kilometers above the earth’s surface. Circularly polarized electromagnetic radiation is transmitted at a first frequency substantially parallel to an earth’s magnetic field line to excite electron cyclotron resonance heating in normally occurring plasma at an altitude of at least about 250 kilometers to generate a mirror force which lifts said plasma to said altitude of at least about 1500 kilometers. Heating is continued at a second frequency to expand the plasma to the apex of said field line whereupon at least some of the plasma is trapped and oscillates between mirror points on said lines. The plasma will be contained within adjacent field lines and will drift to form a shell of relativistic particles around a portion of the earth.
I
nventors: Eastlund; Bernard J. (Spring, TX)
CLAIMS
I claim:
1. A method for establishing a region of a plasma at an altitude of at least about
1500 km above the surface of the earth, said method comprising:
providing at least one source of circularly polarized electromagnetic radiation having a first frequency in the range of from about
1800 to about 3600 kHz;
transmitting said electromagnetic radiation from said earth’s surface substantially parallel to and along at least one of the earth’s naturally occurring and diverging magnetic field lines and focused so as to provide a power flux of about 0.1 to about 1 watt per square centimeter at an altitude of at least 250 km;
adjusting said first frequency of said electromagnetic radiation to a value which will excite a first electron cyclotron resonance within plasma which normally exists adjacent said field line at a first altitude of a
t least about 250 km whereby said electron cyclotron resonance causes heating and further ionization of said plasma to form a plasma having an ion energy of at least 3 ev;
continuing to excite said first electron cyclotron resonance for a time between
0.1 and 1200 seconds sufficient to cause movement of said plasma upward along said diverging magnetic field lines from said first altitude to said region at said altitude of at least about 1500 km;
providing electromagnetic radiation having a second frequency in the range of from about 20 to 1800 kHz and different from said first frequency and which will excite further electron cyclotron resonance in said plasma after it has moved to said region to further heat and to further ionize said plasma and to raise the mirror points of said plasma; and
continuing to excite said second electron cyclotron resonance in said plasma to produce relativistic electrons in said plasma having an electron energy up to 20 million electron volts.
2. The method of claim 1 wherein the excitation of said first electron cyclotron resonance is continued for a sufficient time of about 1200 seconds to expand said plasma upward along said diverging magnetic field lines to the apex of said lines to thereby trap at least some of said plasma which causes said plasma to oscillate between magnetic mirror points on said field lines and to be further heated by stochastic heating.
3. The method of claim 2 wherein said second electron resonance is continued until the electron concentration of said trapped plasma reaches at least about 109 per cubic centimeters.
4. The method of claim 2 wherein the energy of the relativistic electrons in said trapped plasma is at least about 2 million electron volts.
5. The method of claim 4 wherein said first electron cyclotron resonance is continued until a shell of relativistic electrons is formed by natural drift of said electrons around the earth’s circumference.
6. The method of claim 5 wherein the width of said shell is at least about 100 km.
7. The method of claim 6 wherein said shell is formed as an anti-missile shield.
DESCRIPTION
1. Technical Field
The present invention relates to a method for altering a selected region of plasma normally existing at a substantial altitude above the earth’s surface and more particularly relates to a method for producing a magnetically-trapped shell of high density plasma having relativistic particles therein.
2. Background Art
In the late
1950’s, it was discovered that naturally-occurring belts exist at high altitudes above the earth’s surface, and it is now established that these belts result from charged electrons and ions becoming trapped along the magnetic lines of force (field lines) of the earth’s essentially dipole magnetic field. The trapped electrons and ions are confined along the field lines between two magnetic mirrors which exist at spaced apart points along those field lines. The trapped electrons and ions move in helical paths around their particular field lines and “bounce” back and forth between the magnetic mirrors. These trapped electrons and ions can oscillate along the field lines for long periods of time
In the past several years, substantial effort has been made to understand and explain the phenomena involved in belts of trapped electrons and ions and to explore possible ways to control and use these phenomena for beneficial purposes. For example, in the late 1950’s and early 1960’s, both the United States and U.S.S.R. detonated a series of nuclear devices of various yields to generate large numbers of charged particles at various altitudes, e.g., 200 kilometers (km) or greater. This was done in order to establish and study artificial belts of trapped electrons and ions. These experiments established that at least some of the extraneous electrons and ions from the detonated devices did become trapped along field lines in the earth’s magnetosphere to form artificial belts which were stable for prolonged periods of time. For a discussion of these experiments see “The Radiation Belt and Magnetosphere”, W. N. Hess, Blaisdell Publishing Co., 1968, pps. 155 et sec.
Other proposals which have been advanced for altering existing belts of trapped electrons and ions and/or establishing similar artificial belts include
injecting charged particles from a
satellite carrying a payload of radioactive beta-decay material or alpha emitters; and injecting charged particles from a satellite-borne electron accelerator. Still another approach is described in U.S. Pat. No. 4,042,196 wherein a low energy ionized gas, e.g. hydrogen, is released from a synchronous orbiting satellite near the apex of a radiation belt which is naturally occurring in the earth’s magnetosphere to produce a substantial increase in energetic particle precipitation and, under certain conditions, produce a limit in the number of particles that can be stably trapped. This precipitation effect arises from an enhancement of the whistler-mode and ion-cyclotron mode interactions that results from the ionized gas or “cold plasma” injection.
It has also been
proposed to release large clouds of barium in the magnetosphere so that photoionization will increase the cold plasma density, thereby producing electron precipitation through enhanced whistler-mode interactions.
However, in all of the above-mentioned approaches,
the mechanisms involved in triggering the change in the trapped particle phenomena must be actually positioned within the affected zone, e.g., the magnetosphere, before they can be actuated to effect the desired change.
The earth’s ionosphere is not considered to be a “trapped” belt since there are few trapped particles therein. The term “trapped” herein refers to situations where the force of gravity on the trapped particles is balanced by magnetic forces rather than hydrostatic or collisional forces. The charged electrons and ions in the ionosphere also follow helical paths around magnetic field lines within the ionosphere but are not trapped between mirrors as in the case of the trapped belts in the magnetosphere, as the gravitational force on the particles is balanced by collisional or hydrostatic forces.
In recent years, a number of experiments have actually been carried out to modify the ionosphere in some controlled manner to investigate the possibility of a beneficial result. For detailed discussions of these operations see the following papers: (1) Ionospheric Modification Theory; G. Meltz and F. W. Perkins; (2) The Platteville High Power Facility; Carrol et al.; (3) Arecibo Heating Experiments; W. E. Gordon and H. C. Carlson, Jr.; and (4) Ionospheric Heating by Powerful Radio Waves; Meltz et al., all published in Radio Science, Vol. 9, No. 11, November, 1974, at pages 885-888; 889-894; 1041-1047; and 1049-1063, respectively, all of which are incorporated herein by reference. In such experiments, certain regions of the ionosphere are heated to change the electron density and temperature within these regions.
In the Elmo Bumpy Torus (EBT) device, a major controlled fusion device at the Oak Ridge National Laboratory, all heating is provided by microwaves at the electron cyclotron resonance interaction. A ring of hot electrons is formed in the magnetic mirror by a combination of electron cyclotron resonance and stochastic heating. In the EBT, the ring electrons are produced with an average “temperature” of 250 kev (2.5×109 K) and a plasma beta between 0.1 and 0.4 ; see, “A Theoretical Study of Electron - Cyclotron Absorption in Elmo Bumpy Torus”, Batchelor and Goldfinger, Nuclear Fusion, Vol. 20, No. 4 (1980) pps. 403-418.
Electron cyclotron resonance heating has been used in experiments on the earth’s surface to produce and accelerate plasmas in a diverging magnetic field. Kosmahl et al. showed that power was efficiently transferred from the electromagnetic waves and that a fully ionized plasma was accelerated with a
divergence angle of roughly 13 degrees. Optimum neutral gas density was 1.7×1014 per cubic centimeter; see, “Plama Acceleration with Microwaves Near Cyclotron Resonance”, Kosmahl et al., Journal of Applied Physics, Vol. 38, No. 12, November, 1967, pps. 4576-4582.
It has heretofore been recognized that an intense focused beam of charged or neutral particles (e.g., plasma) can carry a potentially destructive amount of energy and is capable
under certain circumstances of melting a hole in a piece of metal or of damaging even shielded electronic circuits. Recently, proposals have been set forth to exploit such particle beams is possible defense mechanisms to be used to protect against offensive missiles which may be launched by a hostile power; see “Particle-Beam Weapons”; J. Parmentola and K. Tsipis; Scientific American, April, 1979, Vol. 240, No. 4, which is incorporated herein by reference.PAZI TUKA
(akcelerator na satelit
)