US4974487A — Plasma propulsion apparatus and method

Claim 1

Independent Claim 278 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the points to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the means for increasing including means for increasing the power applied to the plasma between said fixed points in an approximately linear manner with time as the projectile is accelerated by the gas in the passage, the means for increasing further including pulse forming means responsive to a DC source, the pulse forming means including series inductors and shunt capacitors, switch means for connecting the pulse forming means to the DC source for charging the shunt capacitors prior to the projectile being accelerated by the plasma and for connecting the pulse forming means between the fixed points to supply increasing current to the fixed points and the plasma between them.

Claim 2

Dependent Claim 278 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the points to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the means for increasing including means for increasing the power applied to the plasma between said fixed points in an approximately linear manner with time as the projectile is accelerated by the gas in the passage, the means for increasing further including pulse forming means responsive to a DC source, the pulse forming means including series inductors and shunt capacitors, switch means for connecting the pulse forming means to the DC source for charging the shunt capacitors prior to the projectile being accelerated by the plasma and for connecting the pulse forming means between the fixed points to supply increasing current to the fixed points and the plasma between them.

Claim 3

Independent Claim 222 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) generating a pulsed plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, (b) applying the pulsed plasma to a projectile propelling mass located downstream from an outlet of a source of the plasma, the plasma and mass interacting so the mass is heated by the plasma and the plasma is cooled by the mass, constituents of the mass being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, (c) injecting the high pressure mixture into the bore against the rear of the projectile so the plasma is cooled sufficiently by the mass that the mixture does not cause substantially damage to walls of the bore, and (d) applying current that increases as a function of time to the plasma via the electrodes to control the plasma applied to the mass to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the bore.

Claim 4

Independent Claim 222 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) generating a pulsed plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, (b) applying the pulsed plasma to a projectile propelling mass located downstream from an outlet of a source of the plasma, the plasma and mass interacting so the mass is heated by the plasma and the plasma is cooled by the mass, constituents of the mass being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, (c) injecting the high pressure mixture into the bore against the rear of the projectile so the plasma is cooled sufficiently by the mass that the mixture does not cause substantially damage to walls of the bore, and (d) applying current that increases as a function of time to the plasma via the electrodes to control the plasma applied to the mass to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the bore.

Claim 5

Independent Claim 216 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) applying a plasma jet to a projectile propelling fluid located downstream from an outlet of a source of the jet, the fluid and jet interacting so the fluid is heated by the jet, constituents of the fluid being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, (b) injecting the high pressure mixture into the bore against the rear of the projectile so that the plasma flows longitudinally along the bore axis to accelerate the projectile along the bore axis, the fluid being dragged into the plasma so that the mixture does not cause substantial damage to walls of the bore, and (c) controlling the plasma jet applied to the fluid so there is no substantial decrease in the pressure of the plasma acting on the rear of the projectile while the projectile is being accelerated by the plasma in the bore, to increase the speed of the projectile as time progresses and the projectile is being accelerated by the plasma in the bore, the pressure being maintained substantially constant by increasing the power applied to the plasma approximately linearly with time as the projectile is accelerated by the plasma in the bore.

Claim 6

Independent Claim 216 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) applying a plasma jet to a projectile propelling fluid located downstream from an outlet of a source of the jet, the fluid and jet interacting so the fluid is heated by the jet, constituents of the fluid being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, (b) injecting the high pressure mixture into the bore against the rear of the projectile so that the plasma flows longitudinally along the bore axis to accelerate the projectile along the bore axis, the fluid being dragged into the plasma so that the mixture does not cause substantial damage to walls of the bore, and (c) controlling the plasma jet applied to the fluid so there is no substantial decrease in the pressure of the plasma acting on the rear of the projectile while the projectile is being accelerated by the plasma in the bore, to increase the speed of the projectile as time progresses and the projectile is being accelerated by the plasma in the bore, the pressure being maintained substantially constant by increasing the power applied to the plasma approximately linearly with time as the projectile is accelerated by the plasma in the bore.

Claim 7

Dependent Claim 69 words

A method of claim 3 wherein the plasma is injected into the bore by a capillary tube having a dielectric that is heated to form the plasma by energy from a variable current supply and increasing the square of the current fed by the supply to the plasma in an approximately linear manner as a function of time while the projectile is accelerated in the bore by the plasma.

Claim 8

Dependent Claim 23 words

A method of claim 4 wherein the current increases for about one-half of the time while the projectile is travelling in the bore.

Claim 9

Independent Claim 240 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) generating a pulsed plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, (b) applying the pulsed plasma to a projectile propelling mass located downstream from an outlet of a source of the plasma, the mass and jet interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, (c) injecting the high pressure mixture into the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, the mass being dragged into the plasma so that the mixture does not cause substantial damage to walls of the bore, and (d) applying current that increases as a function of time to the plasma via the electrodes to control the plasma applied to the mass to mix with a heated constituent of the mass to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the bore.

Claim 10

Independent Claim 240 words

A method of accelerating a projectile in a barrel bore comprising the steps of: (a) generating a pulsed plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, (b) applying the pulsed plasma to a projectile propelling mass located downstream from an outlet of a source of the plasma, the mass and jet interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, (c) injecting the high pressure mixture into the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, the mass being dragged into the plasma so that the mixture does not cause substantial damage to walls of the bore, and (d) applying current that increases as a function of time to the plasma via the electrodes to control the plasma applied to the mass to mix with a heated constituent of the mass to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the bore.

Claim 11

Dependent Claim 225 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile comprising a plasma source for supplying a high pressure plasma to the bore behind the projectile so that the propelling plasma has an axial component, the plasma having sufficient pressure to accelerate the projectile in the passage, an electric pulse source, means for connecting the electric pulse source to the plasma source to energize the plasma, the plasma source including an elongated capillary plasma discharge passage having a longitudinal axis surrounded by a wall with many dielectric containers together having a large surface area relative to that of the wall and containing a dielectric ionizable substance from which the plasma is derived, a pair of electrodes spaced from each other at spaced points along the longitudinal axis, said electrodes being connected to said source and positioned relative to said containers to instigate a discharge in the substance of the containers to cause the plasma to propagate along the capillary passage toward the projectile while the projectile is in the passage adapted to receive it, different ones of said containers having different wall characteristics to control the relative ignition times of the substances therein, the pressure being maintained substantially constant by increasing the power applied to the plasma approximately linearly with time as the projectile is accelerated by the plasma in the bore.

Claim 12

Dependent Claim 225 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile comprising a plasma source for supplying a high pressure plasma to the bore behind the projectile so that the propelling plasma has an axial component, the plasma having sufficient pressure to accelerate the projectile in the passage, an electric pulse source, means for connecting the electric pulse source to the plasma source to energize the plasma, the plasma source including an elongated capillary plasma discharge passage having a longitudinal axis surrounded by a wall with many dielectric containers together having a large surface area relative to that of the wall and containing a dielectric ionizable substance from which the plasma is derived, a pair of electrodes spaced from each other at spaced points along the longitudinal axis, said electrodes being connected to said source and positioned relative to said containers to instigate a discharge in the substance of the containers to cause the plasma to propagate along the capillary passage toward the projectile while the projectile is in the passage adapted to receive it, different ones of said containers having different wall characteristics to control the relative ignition times of the substances therein, the pressure being maintained substantially constant by increasing the power applied to the plasma approximately linearly with time as the projectile is accelerated by the plasma in the bore.

Claim 13

Dependent Claim 69 words

A method of claim 7 wherein the plasma is injected into the bore by a capillary tube having a dielectric that is heated to form the plasma by energy from a variable current supply and increasing the square of the current fed by the supply to the plasma in an approximately linear manner as a function of time while the projectile is accelerated in the bore by the plasma.

Claim 14

Dependent Claim 23 words

A method of claim 8 wherein the current increases for about one-half of the time while the projectile is travelling in the bore.

Claim 15

Dependent Claim 10 words

The apparatus of claim 7 wherein the substance is water.

Claim 16

Dependent Claim 13 words

The apparatus of claim 7 wherein the substance is an ablatable powder-like filler.

Claim 17

Dependent Claim 27 words

The apparatus of claim 7 wherein the substance in certain of said containers is a liquid and in others of said containers is an ablatable powder-like material.

Claim 18

Independent Claim 210 words

A method of accelerating a projectile along a longitudinal axis of a passage comprising the steps of generating a plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, the generated plasma forming a high pressure gas acting on the rear of the projectile while the projectile is in the passage, the gas formed by the plasma having sufficient pressure against the rear of the projectile to accelerate the projectile along the passage longitudinal axis, increasing the power applied to the plasma as a function of time so that the power applied to the plasma after initial projectile acceleration has progressively larger values as time progresses by thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, the power increase of the plasma occurring for more than half of the time while the plasma is being generated.

Claim 19

Independent Claim 210 words

A method of accelerating a projectile along a longitudinal axis of a passage comprising the steps of generating a plasma by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a passage having a dielectric wall with an ionizable substance, the electric pulse having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage, the generated plasma forming a high pressure gas acting on the rear of the projectile while the projectile is in the passage, the gas formed by the plasma having sufficient pressure against the rear of the projectile to accelerate the projectile along the passage longitudinal axis, increasing the power applied to the plasma as a function of time so that the power applied to the plasma after initial projectile acceleration has progressively larger values as time progresses by thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, the power increase of the plasma occurring for more than half of the time while the plasma is being generated.

Claim 20

Dependent Claim 48 words

The method of claim 13 wherein the power applied to the plasma between the points and in the transverse cross-sections is increased so pressure applied to the projectile by the gas formed by the plasma is maintained approximately constant while the projectile is being accelerated by the gas.

Claim 21

Dependent Claim 27 words

The method of claim 13 wherein the high pressure gas is formed by an interaction between the plasma and a fluid containing a substantial quantity of hydrogen.

Claim 22

Dependent Claim 35 words

The method of claim 13 wherein the high pressure gas is formed by an interaction between the plasma and a confined fluid located between an outlet for a source of the plasma and the projectile.

Claim 23

Independent Claim 252 words

A method of accelerating a projectile along a longitudinal axis of a passage comprising the steps of generating a plasma to form a high pressure gas acting on the rear of the projectile while the projectile is in the passage, the gas formed by the plasma having sufficient pressure against the rear of the projectile to accelerate the projectile along the passage longitudinal axis, increasing the speed of the projectile as time progresses and the projectile is being accelerated by the plasma in the passage by increasing the power applied to the plasma, the power increase occurring throughout the length of a region between a pair of fixed points in traverse cross-sections of a passage in which the plasma is derived, the power increase of the plasma between the points and in the transverse cross-sections occurring for approximately the entire time while the plasma is between the fixed points to control the plasma so there is no substantial decrease in the pressure of the gas acting on the rear of the projectile while the projectile is being accelerated by the gas in the passage, the plasma being derived by applying a discharge current between the fixed points in a capillary passage having a dielectric wall with a substance that is ionized by the discharge current, the power being increased by increasing the square of the current applied to the plasma between the fixed points in an approximately linear manner as a function of time while the projectile is accelerated by the gas.

Claim 24

Independent Claim 252 words

A method of accelerating a projectile along a longitudinal axis of a passage comprising the steps of generating a plasma to form a high pressure gas acting on the rear of the projectile while the projectile is in the passage, the gas formed by the plasma having sufficient pressure against the rear of the projectile to accelerate the projectile along the passage longitudinal axis, increasing the speed of the projectile as time progresses and the projectile is being accelerated by the plasma in the passage by increasing the power applied to the plasma, the power increase occurring throughout the length of a region between a pair of fixed points in traverse cross-sections of a passage in which the plasma is derived, the power increase of the plasma between the points and in the transverse cross-sections occurring for approximately the entire time while the plasma is between the fixed points to control the plasma so there is no substantial decrease in the pressure of the gas acting on the rear of the projectile while the projectile is being accelerated by the gas in the passage, the plasma being derived by applying a discharge current between the fixed points in a capillary passage having a dielectric wall with a substance that is ionized by the discharge current, the power being increased by increasing the square of the current applied to the plasma between the fixed points in an approximately linear manner as a function of time while the projectile is accelerated by the gas.

Claim 25

Dependent Claim 23 words

A method of claim 17 wherein the current increases for about one-half of the time while the projectile is travelling in the passage.

Claim 26

Dependent Claim 243 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile comprising means for applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, a plasma source for generating a plasma having a flow path into the means for applying the high pressure gas to the rear of the projectile, the plasma source including an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shaped and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, so increased power is applied to the plasma between the electrodes, the power increase being a function of time so that the power applied to the plasma after initial projectile acceleration has progressively larger values as time progresses and occurring for at least half of the time while the plasma is between the points.

Claim 27

Dependent Claim 243 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile comprising means for applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, a plasma source for generating a plasma having a flow path into the means for applying the high pressure gas to the rear of the projectile, the plasma source including an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shaped and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, so increased power is applied to the plasma between the electrodes, the power increase being a function of time so that the power applied to the plasma after initial projectile acceleration has progressively larger values as time progresses and occurring for at least half of the time while the plasma is between the points.

Claim 28

Dependent Claim 54 words

The apparatus of claim 19 wherein the means for increasing includes means for increasing the power applied to the plasma between said fixed points and in said transverse cross-sections to maintain the pressure acting on the rear of the projectile substantially constant while the projectile is being accelerated by the gas in the passage.

Claim 29

Dependent Claim 117 words

The apparatus of claim 19 wherein the projectile receiving passage is downstream of the plasma source passage, the plasma source including means for injecting plasma from the plasma source passage into the projectile receiving passage, a confined mass of projectile propelling fluid positioned between the injecting means and the passage through which the projectile is accelerated, the power increase energizing the plasma so plasma initially injected through the injecting means into the fluid mixes with the fluid to cool the plasma and heat the fluid, plasma subsequently injected into the fluid heating the fluid sufficiently so a constituent of the fluid has a highly energetic gaseous state sufficient to accelerate the projectile in the projectile receiving passage.

Claim 30

Dependent Claim 287 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, the plasma source including an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, the increasing current applying increasing power to the plasma between the electrodes, the power increase occurring for at least half the time while the plasma is between the electrodes to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the electrodes to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the means for increasing including means for increasing the power applied to the plasma between said electrodes in an approximately linear manner with time as the projectile is accelerated by the gas in the passage.

Claim 31

Dependent Claim 287 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, the plasma source including an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage, the increasing current applying increasing power to the plasma between the electrodes, the power increase occurring for at least half the time while the plasma is between the electrodes to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the electrodes to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the means for increasing including means for increasing the power applied to the plasma between said electrodes in an approximately linear manner with time as the projectile is accelerated by the gas in the passage.

Claim 32

Dependent Claim 19 words

The apparatus of claim 22 wherein the means for increasing includes pulse forming means responsive to a DC source.

Claim 33

Dependent Claim 236 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the points to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the plasma source comprising means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for increasing including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes.

Claim 34

Dependent Claim 236 words

Apparatus for accelerating a projectile in a passage adapted to receive the projectile by applying a high pressure gas to the rear of the projectile while the projectile is in the passage, the gas having sufficient pressure to accelerate the projectile along the passage longitudinal axis toward an open end of the passage, the apparatus comprising a plasma source for generating a plasma having a flow path toward the rear of the projectile, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points to energize the plasma so that pressure acting on the rear of the projectile resulting from the increasing power applied between the points to the plasma does not decrease substantially while the projectile is being accelerated by the gas in the passage, the plasma source comprising means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for increasing including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes.

Claim 35

Dependent Claim 60 words

The apparatus of claim 24 wherein the capillary passage has a longitudinal axis aligned with the passage along which the projectile is accelerated, the capillary passage having a nozzle at one end for injecting the plasma with an axial component into the passage along which the projectile is accelerated to a position behind an initial rest position of the projectile.

Claim 36

Dependent Claim 51 words

The apparatus of claim 24 wherein the current source includes means for increasing the current applied to the electrodes while the projectile is being accelerated to maintain the pressure behind the projectile in the passage through which the projectile is accelerated substantially constant while projectile is being accelerated by the gas.

Claim 37

Dependent Claim 53 words

The apparatus of claim 24 wherein the current source includes means for increasing the current applied to the electrodes as a function of time to cause the power applied to the plasma between the electrodes to increase as a substantially linear function of time while the projectile is being accelerated by the gas.

Claim 38

Dependent Claim 158 words

Apparatus for accelerating a projectile comprising a plasma source, the plasma source including means for forming a capillary passage having a dielectric wall with an ionizable substance, means for establishing a discharge current between two, fixed spaced points along the capillary passage, the discharge current interacting with the ionizable substance to form a plasma and a gas having sufficient pressure to accelerate the projectile in a passage in which the projectile is located, the means for establishing including means for increasing the current as a function of time throughout the length of the capillary passage between the points for at least half of the time while the plasma is derived between the points so that the current applied to the plasma after initial projectile acceleration has progressively larger values as time progresses, and means for supplying the gas to the projectile while the projectile is in the passage through which the projectile is accelerated to accelerate the projectile.

Claim 39

Dependent Claim 158 words

Apparatus for accelerating a projectile comprising a plasma source, the plasma source including means for forming a capillary passage having a dielectric wall with an ionizable substance, means for establishing a discharge current between two, fixed spaced points along the capillary passage, the discharge current interacting with the ionizable substance to form a plasma and a gas having sufficient pressure to accelerate the projectile in a passage in which the projectile is located, the means for establishing including means for increasing the current as a function of time throughout the length of the capillary passage between the points for at least half of the time while the plasma is derived between the points so that the current applied to the plasma after initial projectile acceleration has progressively larger values as time progresses, and means for supplying the gas to the projectile while the projectile is in the passage through which the projectile is accelerated to accelerate the projectile.

Claim 40

Dependent Claim 55 words

The apparatus of claim 28 further including a barrel downstream of the capillary passage in which the projectile is initially positioned, the barrel having a bore positioned to be responsive to the gas derived from the interaction of the current and the ionizable substance, the bore being the passage through which the projectile is accelerated.

Claim 41

Dependent Claim 92 words

The apparatus of claim 29 further including a confined mass of projectile propelling fluid positioned between the ionizable substance of the plasma source and a location behind the projectile in the passage in which the projectile is accelerated, the confined mass of propelling fluid interacting with the plasma injected into the fluid to cool the plasma and heat the fluid, the plasma heating the fluid sufficiently so a constituent of the fluid has a highly energetic gaseous state sufficient to accelerate the projectile in the passage in which the projectile is accelerated.

Claim 42

Dependent Claim 20 words

The apparatus of claim 30 wherein the confined mass of fluid is downstream of an outlet of the plasma source.

Claim 43

Dependent Claim 150 words

Apparatus for accelerating a projectile comprising a plasma source, the plasma source including means for forming a capillary passage having a dielectric wall with an ionizable substance, means for establishing a discharge current between two, fixed spaced points along the capillary passage, the discharge current interacting with the ionizable substance to form a plasma and a gas having sufficient pressure to accelerate the projectile in a passage in which the projectile is located, the means for establishing including means for substantially increasing the current throughout the length of the capillary passage between the points for at least half the time while the plasma is derived between the points, the square of the current established between the two fixed points increasing approximately linearly with time, and means for supplying the gas to the projectile while the projectile is in the passage through which the projectile is accelerated to accelerate the projectile.

Claim 44

Dependent Claim 150 words

Apparatus for accelerating a projectile comprising a plasma source, the plasma source including means for forming a capillary passage having a dielectric wall with an ionizable substance, means for establishing a discharge current between two, fixed spaced points along the capillary passage, the discharge current interacting with the ionizable substance to form a plasma and a gas having sufficient pressure to accelerate the projectile in a passage in which the projectile is located, the means for establishing including means for substantially increasing the current throughout the length of the capillary passage between the points for at least half the time while the plasma is derived between the points, the square of the current established between the two fixed points increasing approximately linearly with time, and means for supplying the gas to the projectile while the projectile is in the passage through which the projectile is accelerated to accelerate the projectile.

Claim 45

Independent Claim 129 words

A method of accelerating a projectile comprising the steps of applying a discharge current to an ionizable substance on a dielectric wall of a capillary passage via a pair of electrodes longitudinally spaced from each other along the passage, the discharge current forming a plasma in the capillary as a result of an interaction between the current and the substance, substantially increasing the current for most of the time while the plasma is derived between the electrodes so that the current applied to the plasma after initial projectile acceleration has progressively larger values as time progresses, the plasma establishing a high pressure gas having sufficient pressure behind the projectile to accelerate the projectile, and applying the high pressure gas to the rear of the projectile to accelerate the projectile.

Claim 46

Independent Claim 129 words

A method of accelerating a projectile comprising the steps of applying a discharge current to an ionizable substance on a dielectric wall of a capillary passage via a pair of electrodes longitudinally spaced from each other along the passage, the discharge current forming a plasma in the capillary as a result of an interaction between the current and the substance, substantially increasing the current for most of the time while the plasma is derived between the electrodes so that the current applied to the plasma after initial projectile acceleration has progressively larger values as time progresses, the plasma establishing a high pressure gas having sufficient pressure behind the projectile to accelerate the projectile, and applying the high pressure gas to the rear of the projectile to accelerate the projectile.

Claim 47

Independent Claim 121 words

A method of accelerating a projectile comprising the steps of applying a discharge current to an ionizable substance on a dielectric wall of a capillary passage via a pair of electrodes longitudinally spaced from each other along the passage, the discharge current forming a plasma in the capillary as a result of an interaction between the current and the substance, substantially increasing the current between the electrodes for at least half the time while the plasma is derived such that the square of the current increases approximately linearly, the plasma establishing a high pressure gas having sufficient pressure behind the projectile to accelerate the projectile, and applying the high pressure gas to the rear of the projectile to accelerate the projectile.

Claim 48

Independent Claim 121 words

A method of accelerating a projectile comprising the steps of applying a discharge current to an ionizable substance on a dielectric wall of a capillary passage via a pair of electrodes longitudinally spaced from each other along the passage, the discharge current forming a plasma in the capillary as a result of an interaction between the current and the substance, substantially increasing the current between the electrodes for at least half the time while the plasma is derived such that the square of the current increases approximately linearly, the plasma establishing a high pressure gas having sufficient pressure behind the projectile to accelerate the projectile, and applying the high pressure gas to the rear of the projectile to accelerate the projectile.

Claim 49

Dependent Claim 106 words

The method of claim 34 further including the step of applying the plasma in the capillary passage to a confined mass of fluid located between the ionizable substance and a passage in which the projectile is accelerated, the plasma mixing with the fluid to cool the plasma and heat the fluid so a constituent of the fluid has a highly energetic gaseous state sufficient to accelerate the projectile in the passage in which the projectile is accelerated, and applying the highly energetic gaseous constituent of the fluid to the rear of the projectile to accelerate the projectile in the passage in which the projectile is located.

Claim 50

Independent Claim 189 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a pulsed plasma in a capillary passage having a pair of electrodes longitudinally spaced from each other in the passage, applying the pulsed plasma formed in the capillary passage to a projectile propelling mass located in a flow path between the passage and the bore, the mass and plasma interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the mass into the plasma so that the mixture does not cause substantial damage to the bore wall, and progressively increasing the power applied to the electrodes in the capillary passage while the projectile is being accelerated, the progressively increasing power being applied to the plasma via the electrodes.

Claim 51

Independent Claim 189 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a pulsed plasma in a capillary passage having a pair of electrodes longitudinally spaced from each other in the passage, applying the pulsed plasma formed in the capillary passage to a projectile propelling mass located in a flow path between the passage and the bore, the mass and plasma interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the mass into the plasma so that the mixture does not cause substantial damage to the bore wall, and progressively increasing the power applied to the electrodes in the capillary passage while the projectile is being accelerated, the progressively increasing power being applied to the plasma via the electrodes.

Claim 52

Dependent Claim 10 words

The method of claim 36 wherein the constituent is hydrogen.

Claim 53

Independent Claim 239 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a plasma jet in a capillary passage, applying the plasma jet formed in the capillary passage to a projectile propelling fluid located between the passage and the bore, the fluid and jet interacting so the fluid is heated by the jet, constituents of the fluid being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the fluid into the plasma so that the mixture does not cause substantially damage to the bore wall, and controlling the plasma jet so there is no substantial decrease in the pressure of the mixture acting on the rear of the projectile while the projectile is being accelerated by the mixture in the bore to increase the speed of the projectile as time progresses, the pressure being maintained substantially constant by increasing the power applied to the plasma by way of a pair of electrodes in the capillary passage by approximately linearly increasing the square of current fed to the pair of electrodes as a function of time while the projectile is accelerated in the bore.

Claim 54

Independent Claim 239 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a plasma jet in a capillary passage, applying the plasma jet formed in the capillary passage to a projectile propelling fluid located between the passage and the bore, the fluid and jet interacting so the fluid is heated by the jet, constituents of the fluid being sufficiently heated by the jet to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the fluid into the plasma so that the mixture does not cause substantially damage to the bore wall, and controlling the plasma jet so there is no substantial decrease in the pressure of the mixture acting on the rear of the projectile while the projectile is being accelerated by the mixture in the bore to increase the speed of the projectile as time progresses, the pressure being maintained substantially constant by increasing the power applied to the plasma by way of a pair of electrodes in the capillary passage by approximately linearly increasing the square of current fed to the pair of electrodes as a function of time while the projectile is accelerated in the bore.

Claim 55

Independent Claim 205 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a pulsed plasma in a capillary passage by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a capillary passage having a dielectric wall with an ionizable substance, applying the pulsed plasma formed in the capillary passage to a projectile propelling mass located between the passage and the bore, the mass and plasma interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the mass into the plasma so that the mixture does not cause substantial damage to the bore wall, and controlling the plasma to mix with the constituents by progressively increasing the current and power applied to the plasma between the electrodes while the projectile is in the bore and is being accelerated.

Claim 56

Independent Claim 205 words

A method of accelerating a projectile in a barrel bore comprising the steps of forming a pulsed plasma in a capillary passage by applying an electric pulse to a pair of electrodes spaced longitudinally from each other along the length of a capillary passage having a dielectric wall with an ionizable substance, applying the pulsed plasma formed in the capillary passage to a projectile propelling mass located between the passage and the bore, the mass and plasma interacting so the mass is heated by the plasma, constituents of the mass being sufficiently heated by the plasma to become mixed with the plasma to form a high pressure mixture, the mixture having sufficient pressure to accelerate the projectile in the bore, applying the high pressure mixture to the bore against the rear of the projectile so that the mixture flows longitudinally along the bore axis to accelerate the projectile along the bore axis, dragging the mass into the plasma so that the mixture does not cause substantial damage to the bore wall, and controlling the plasma to mix with the constituents by progressively increasing the current and power applied to the plasma between the electrodes while the projectile is in the bore and is being accelerated.

Claim 57

Dependent Claim 171 words

In combination, means forming an elongated passage, means for establishing a directed plasma flowing longitudinally through the elongated passage, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in the elongated passage in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points, the means for establishing including means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for applying including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes, wherein the means for increasing includes means for increasing the power applied to the plasma between said fixed points in an approximately linear manner with time.

Claim 58

Dependent Claim 171 words

In combination, means forming an elongated passage, means for establishing a directed plasma flowing longitudinally through the elongated passage, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other along the plasma flow path in the elongated passage in transverse cross-sections of the plasma flow path, the power increase occurring for at least half the time while the plasma is between the points, the means for establishing including means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for applying including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes, wherein the means for increasing includes means for increasing the power applied to the plasma between said fixed points in an approximately linear manner with time.

Claim 59

Dependent Claim 139 words

In combination, means forming an elongated passage, means for establishing a plasma in the elongated passage, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other in the plasma in the elongated passage in transverse cross-sections between the fixed points, the power increase occurring for at least half the time while the plasma is between the points, the means for establishing including means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for applying including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes.

Claim 60

Dependent Claim 139 words

In combination, means forming an elongated passage, means for establishing a plasma in the elongated passage, and means for applying increasing power to the plasma throughout a region between a pair of fixed points longitudinally spaced from each other in the plasma in the elongated passage in transverse cross-sections between the fixed points, the power increase occurring for at least half the time while the plasma is between the points, the means for establishing including means for forming a capillary passage having a dielectric wall with an ionizable substance, the means for applying including a pair of electrodes and a variable current source connected to said electrodes, one of said electrodes being connected to the dielectric wall at each of said points, the variable current source supplying a current that increases as a function of time to the electrodes.

Claim 61

Dependent Claim 41 words

The combination of claim 41 wherein the variable current source includes means for applying a current having a squared value that increases approximately linearly as a function of time for approximately the entire time while the plasma is between the points.

Claim 62

Dependent Claim 98 words

In combination, means forming an elongated passage having a dielectric wall with an ionizable substance, a pair of electrodes spaced longitudinally from each other along the length of the passage, an electric pulse source connected to said electrodes for establishing a directed plasma flowing longitudinally through the elongated passage, the electric pulse source applying increasing current and power to the electrodes and the plasma between the electrodes, the current and power increase occurring for at least half the time while the plasma is between the points, the power applied to the plasma between the electrodes increasing approximately linearly.

Claim 63

Dependent Claim 98 words

In combination, means forming an elongated passage having a dielectric wall with an ionizable substance, a pair of electrodes spaced longitudinally from each other along the length of the passage, an electric pulse source connected to said electrodes for establishing a directed plasma flowing longitudinally through the elongated passage, the electric pulse source applying increasing current and power to the electrodes and the plasma between the electrodes, the current and power increase occurring for at least half the time while the plasma is between the points, the power applied to the plasma between the electrodes increasing approximately linearly.

Claim 64

Dependent Claim 147 words

Apparatus for accelerating a projectile through a bore of a barrel for receiving the projectile comprising a plasma source for forming a high pressure propelling gas in a chamber behind the projectile so that the propelling gas accelerates the projectile in the bore, an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage.

Claim 65

Dependent Claim 147 words

Apparatus for accelerating a projectile through a bore of a barrel for receiving the projectile comprising a plasma source for forming a high pressure propelling gas in a chamber behind the projectile so that the propelling gas accelerates the projectile in the bore, an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage and for thereafter applying to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving passage.

Claim 66

Dependent Claim 160 words

Apparatus for accelerating a projectile through a bore of a barrel for receiving the projectile comprising a plasma source for forming a high pressure propelling gas in a chamber behind the projectile so that the propelling gas accelerated the projectile in the bore, an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage to (a) initially form the plasma in the passage without moving the projectile, and (b) thereafter apply to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving bore.

Claim 67

Dependent Claim 160 words

Apparatus for accelerating a projectile through a bore of a barrel for receiving the projectile comprising a plasma source for forming a high pressure propelling gas in a chamber behind the projectile so that the propelling gas accelerated the projectile in the bore, an electric pulse source connected to energize the plasma, the plasma source including a passage having a dielectric wall with an ionizable substance and a pair of electrodes spaced longitudinally from each other along the length of the passage, the electric source having a predetermined wave shape and duration for applying a discharge voltage to the electrodes to establish a discharge in the passage to (a) initially form the plasma in the passage without moving the projectile, and (b) thereafter apply to the plasma current that increases as a function of time to cause additional propelling gas to be applied to the rear of the projectile while the projectile is being accelerated through the projectile receiving bore.

Claim 68

Dependent Claim 11 words

The apparatus of claim 45 wherein the applied current increases monotonically.

Claim 69

Dependent Claim 48 words

The apparatus of claim 46 wherein the electric pulse source includes means for deriving a wave shape such that the square of the current applied by the electric pulse source to the plasma by the electrodes increases approximately linearly as the elapsed time of the wave shape increases.

Claim 70

Dependent Claim 45 words

The apparatus of claim 47 wherein the electric pulse source includes means for deriving a wave shape such that the square of the current applied by the electric pulse source to the plasma increases approximately linearly as the elapsed time of the wave shape increases.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-12-03	1994-06-04	1994-12-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-12-03	1998-06-04	1998-12-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-12-03	2002-06-04	2002-12-04	$7700.00	Window Closed / Lapsed

Plasma propulsion apparatus and method

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