Patent
US3713157: ENERGY ABSORPTION BY A RADIOISOTOPE PRODUCED PLASMA
August, Henry, Sepulveda, CA North American Aviation, Inc
Filed July 31, 1964
Issued Jan 23, 1973
This invention relates to an arrangement for producing an ionized plasma adjacent a surface and in particular it relates to providing a body with a coating capable of injecting kinetic energy into an adjacent gaseous medium thereby reducing the frictional drag of the body when traveling through such a medium, as well as being capable of producing an ionized plasma sheath that will absorb or attenuate the transmission of eletromagnetic and longitudinal type energy therethrough.
I claim:
1. An arrangement for altering the kinetic and electrical properties of a fluid medium adjacent a surface comprising a body having a surface in contact with a fluid medium and a coating on said surface emitting energy quanta into the fluid medium to ionize and to inject kinetic energy into such medium whereby the propagation of electromagnetic and longitudinal wave energy through the fluid medium is attenuated and the frictional drag on said surface of such fluid medium when moving relative to the surface is reduced.
2. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 1 wherein said coating comprises a thin film coating of a radioisotope material.
3. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 2 and further including a thin coating of a protective material deposited over said radioisotope material to prevent dislodgment of such material.
4. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 2 wherein said coating comprises a thin film coating of an alpha emitting radioisotope material.
5. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 2 wherein the majority of the electrically charged particles generated by the radioisotope material have an energy level of from 4 to 2,000 electron volts.
6. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 1 wherein said coating comprises a thin film of Polonium 210 plated onto a metal substrate.
7. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 6 and further including a thin flash coating of gold plated over said Polonium 210.
8. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 1 and further including means for injecting into the fluid medium to be ionized a material of a lower ionization potential level than that of the fluid medium to assist in initiation and enhancement of the ionization process.
9. An arrangement for altering the kinetic and electrical properties of a fluid medium as set forth in claim 1 and further including means for superimposing a DC magnetic field on the ionized fluid medium to enhance the ionization process.
10. A method for decreasing the electromagnetic and longitudinal wave transmission properties of a gaseous medium adjacent a surface comprising providing a body having a surface capable of generating or reflecting electromagnetic and longitudinal wave energy and coating onto said surface a radioisotope material for producing an ionized plasma adjacent said coating for decreasing the amount of radiated energy passing through said plasma.
11. A method for decreasing the wave transmission properties of a gaseous medium adjacent a surface as set forth in claim 10 wherein said coating is selected from the group consisting of Polonium 210, Promethium 147, Curium 242, or Thorium 204.
12. A method for reducing the radar and infrared cross section of a surface subjected to impingement of electromagnetic wave energy comprising providing a body capable of reflecting electromagnetic wave energy and applying a radioisotope coating onto said body for producing an ionized plasma sheath adjacent to and extending outwardly from said coating for decreasing the amount of electromagnetic wave energy radiated to and reflected from said body through said plasma sheath.
13. A method for reducing the skin friction and heat transfer from a surface having relative movement of a fluid thereover comprising applying to said surface a material, said material undergoing a nuclear transformation resulting in the emission of high kinetic energy particles into the boundary layer adjacent said surface and moving said surface relative to said fluid whereby the skin friction and heat transfer from said surface are thereby reduced.
14. As an article of manufacture, an aerospace vehicle surface adapted to be exposed to the adjacent atmosphere having a thin film coating of a radioisotope material capable of emitting particles having sufficient energy to ionize the adjacent atmosphere.
15. A method for reducing the radar and infrared cross section of a surface as set forth in claim 12, including the step of absorbing, refracting and diffracting the generated or reflected electromagnetic wave energy in said ionized sheath so that the electromagnetic energy radiated to and reflected from said body is decreased.
16. A method for reducing the radar and infrared cross section of a surface as set forth in claim 12, including the step of generating an electron gradient in said sheath which gradually decreases with increasing distance from the coating to create a substantial impedance match to incident electromagnetic energy so that no substantial sharply defined outer boundary to said plasma sheath exists to act as a reflective surface to said electromagnetic wave.