Multi-megawatt pulsed inductive thruster

• US 5,207,760 A
• Filed: 07/23/1991
• Issued: 05/04/1993
• Est. Priority Date: 07/23/1991
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Corporation
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Hieatt, James L., Lovberg, Ralph H., Dailey, Charles L.
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): KOCHAROV, MICHAEL
• Application Number:
  US07/734,723
• Time in Patent Office: 651 Days
• Field of Search: 60/202, 60/203.1, 60/204, 250/423 R, 315/111.41, 315/111.81, 313/359.1, 313/361.1
• US Class Current: 60/202
• CPC Class Codes: F03H 1/0081 Electromagnetic plasma thrusters
• CPC Class Codes: F03H 1/0087 Electro-dynamic thrusters, e.g. pulsed plasma thrusters
• CPC Class Codes: G21D 5/02 Reactor and engine structurally combined, e.g. portable
• CPC Class Codes: H05H 1/40 using applied magnetic fields, e.g. for focusing or rotating the arc cf. B23K9/08, B23K9/073
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin

Abstract

This invention discloses an engine for use in sustained space travel. The engine is of an electric type powered by a nuclear reactor. The electric engine includes a pulsed inductive magnetic thruster. A gas is discharged against an inductor comprising a series of parallel coils arranged in a spiral fashion. Each coil consists of four separate electrically connected coil sections. Each coil section traverses one-quarter of the distance around the inductor from an outer perimeter to an inner perimeter to form a single closed loop. A capacitor is electrically connected to two outer perimeter connector points for each coil forming a Marx Bank arrangement. All capacitors are charged to full charge and discharged simultaneously by a trigger generator immediately after a puff of propellant gas reaches the inductor. The high induced EMF in the inductor caused by the multiple capacitors in series in a single loop creates a rapidly rising magnetic field which ionizes the propellant gas. The current and magnetic field in the ionized gas drives the gas away from the coil creating the thrust which drives the spaceship.

Claims

1. A method of providing thrust by means of an inductive type magnetic thruster comprising the steps of:

connecting a series of electrically parallel coils in a flat, spiral inductor arrangement, wherein each coil includes at least two coil sections such that each coil section is electrically connected to an outer perimeter of the inductor and an inner perimeter of the inductor;

connecting a series of discharge capacitors in electrical connection with the inductor such that each coil is electrically connected to at least two capacitors;

injecting an ionizable gas towards the inductor such that the gas substantially uniformly spreads out over a face of the conductor; and

simultaneously discharging all of the capacitors of the series of capacitors to create a magnetic field which ionizes the gas and forces the gas away from the inductor providing thrust.

2. The method according to claim 1 wherein the step of connecting a series of coil sections includes the steps of connecting a first coil section in electrical contact with a first outer connective point at the outer perimeter of the inductor such that the first coil section travels one-quarter of the distance around the inductor and electrically connects to a first inner connective point on the inner perimeter of the inductor, connecting a second coil section in electrical contact with the first inner connective point such that the second coil section travels one-quarter of the distance around the inductor to be electrically connected to a second outer connective point opposite to the first outer connective point on the outer perimeter of the inductor, connecting a third coil section in electrical contact with the second outer connective point on the outer perimeter such that the third coil section travels one-quarter of the distance around the inductor to be electrically connected to a second inner connective point opposite to the first inner connective point on the inner perimeter of the inductor, and connecting a fourth coil section in electrical contact with the second inner connective point on the inner perimeter such that the fourth coil section travels one-quarter of the distance around the inductor to be connected to the first connective point on the outer perimeter to form a closed coil loop.

3. The method according to claim 1 wherein the step of connecting a series of capacitors includes electrically connecting a capacitor to the first outer connective point and electrically connecting a capacitor to the second outer connective point of each coil.

4. The method according to claim 1 wherein the steps of connecting the first coil section and the third coil section includes positioning the first coil section and the third coil section on one face of the inductor and the steps of connecting the second coil section and a fourth coil section include positioning the second coil section and the fourth coil section on an opposite face of the inductor.

5. The method according to claim 1 wherein the step of connecting a series of capacitors includes electrically connecting each capacitor to four consecutive outer connective points.

6. The method according to claim 1 wherein the step of discharging the capacitors includes discharging the capacitors through a solid state switch.

7. The method according to claim 1 wherein the step of injecting the gas includes injecting the gas at a pulsed rate such that each pulse is injected and ionized and thrusted away from the coil prior to the next pulse of gas being injected and wherein the capacitors are simultaneously charged before the next pulse of gas arrives at the inductor.

8. An inductive type magnetic thruster comprising:

a series of electrically parallel coils forming an inductor arranged in a spiral pattern, each coil of said series of coils including at least two coil sections, each coil section being electrically connected at an outer perimeter of the inductor and an inner perimeter of the inductor;

a series of discharge capacitors wherein at least two of the capacitors are electrically connected to each coil; and

gas injection means for injecting a gas towards the inductor, wherein discharge of the capacitors creates a rising magnetic field which causes ionization of the gas providing the thrust.

9. The thruster according to claim 8 wherein each coil of the series of coils comprises four coil sections, a first coil section being electrically connected to a first outer connective point at the outer perimeter of the inductor and traveling one-quarter of the distance around the inductor to a first inner connective point on the inner perimeter of the inductor, a second coil section being electrically connected to the first inner connective point and traveling one-quarter of the distance around the inductor to a second outer connective point opposite the first outer connective point on the outer perimeter of the inductor, a third coil section being electrically connected to the second outer connective point on the outer perimeter and traveling one-quarter of the distance around the inductor to a second inner connective point opposite the first inner connective point on the inner perimeter of the inductor, and a fourth coil section being electrically connected to the second inner connective point on the inner perimeter and traveling one-quarter of the distance around the inductor to the first connective point on the outer perimeter forming a closed coil loop.

10. The thruster according to claim 9 wherein a capacitor is electrically connected to the first outer connective point and a capacitor is electrically connected to the second outer connective point of each coil.

11. The thruster according to claim 8 further comprising a triggering means for discharging all of the capacitors simultaneously.

12. The thruster according to claim 9 wherein the first coil section and the third coil section are positioned on one face of the inductor and the second coil section and the fourth coil section are positioned on an opposite face of the inductor.

13. The thruster according to claim 8 wherein the gas injection means is a conical nozzle positioned substantially in line with the center of the inductor such that gas introduced by the nozzle spreads out uniformly across a front face of the inductor forming a gas sheet.

14. The thruster according to claim 10 wherein the inductor includes 36 separate, parallel coils.

15. The thruster according to claim 14 wherein the series of capacitors is 18 capacitors such that each capacitor is electrically connected to four consecutive outer connective points.

16. The thruster according to claim 8 wherein the gas injection means injects the gas at a pulsed rate.

17. The thruster according to claim 8 wherein each capacitor is discharged into a coil through a switch wherein the switch is a solid state switch.

18. An inductive type magnetic thruster comprising:

a series of parallel-connected coils forming an inductor arranged in a spiral pattern, each coil of said series of coils including four coil sections, a first coil section being electrically connected to a first outer connective point at an outer perimeter of the conductor and traveling one-quarter of the distance around the inductor to a first inner connective point on an inner perimeter of the inductor, a second coil section being electrically connected to the first inner connective point and traveling one-quarter of the distance around the inductor to a second outer connective point opposite the first outer connective point on the outer perimeter of the conductor, a third coil section being electrically connected to the second outer connective point on the outer perimeter and traveling one-quarter of the distance around the inductor to a second inner connective point opposite the first inner connective point on the inner perimeter of the inductor, and a fourth coil section being electrically connected to the second inner connective point on the inner perimeter and traveling one-quarter of the distance around the inductor to the first connective point on the outer perimeter forming a closed coil loop;

a series of discharge capacitors electrically connected to the inductor, wherein at least two of the capacitors are connected to each coil loop; and

gas injection means for injecting a gas towards the inductor, wherein discharge of the capacitors creates a magnetic field which ionizes the gas and provides the thrust.

19. The thruster according to claim 18 wherein a capacitor of the series of capacitors is electrically connected to the first outer connective point and a capacitor of the series of capacitors is electrically connected to the second outer connective point of each coil.

20. The thruster according to claim 18 wherein each capacitor of the series of capacitors is electrically connected to four consecutive outer connective points of four coils.

21. The thruster according to claim 18 wherein the inductor includes 36 separate coils.

22. The thruster according to claim 18 wherein the first coil section and the third coil section of each coil are positioned on one face of the inductor and the second coil section and the fourth coil section of each coil are positioned on an opposite face of the inductor.

23. The thruster according to claim 18 further comprising a triggering means for discharging all of the capacitors simultaneously.

24. The thruster according to claim 18 wherein the gas injection means injects the gas at a pulsed rate.

25. The thruster according to claim 18 wherein each capacitor is discharged into a coil through a switch wherein said switch is a solid state switch.