Abstract: Disclosed is a method and an apparatus for accelerating and shooting a flying body at superhigh speed, consisting of a capacitor in which a high electric charge can be stored; a primary coil connected to the capacitor via a switching means; a conductive cylindrical liner disposed in the primary coil; an opening defined on a cylindrical wall of the cylindrical liner; and a flying body interposed in the opening and assuming electrical continuity with the liner; wherein a high electric charge stored in the capacitor is momentarily applied to the primary coil so as to compress abruptly the cylindrical liner radially inward and to shoot the flying body interposed in the opening toward the axis of the liner.

Abstract: A railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with an insulator material. The insulator material allows the composite insulator to stand off the voltages in a plasma armature even under high radiation flux conditions. Below the conducting material's ablation threshold the amount of ablation produced by the composite insulator is reduced by the reduction of insulator surface area exposed to the radiation. This allows better control of armature growth, mass acceleration by the plasma armature, secondary formation, and other factors normally found to retard projectile acceleration.

Abstract: The invention relates to a propellant charge comprising a compact propellant and a method for electrically initiating and controlling the burning of such a propellant charge. Electrothermal energy is supplied to the propellant charge by feeding electric current over electrically conductive surfaces (6, 7, 19) in the propellant, and that said supply is made to different parts or zones (15) of the propellant charge at different points of time during the burning.The invention specifically relates to a projectile propellant charge having a first end (9) facing the projectile (4) and a second end (10) facing the back (3) of the weapon. The electrothermal energy is then supplied to the propellant charge, beginning in the first end thereof and then successively to the second end thereof by feeding the current at each point of time over an axially restricted part (15) of the propellant charge.

Abstract: A railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with an insulator material. The insulator material allows the composite insulator to stand off the voltages in a plasma armature even under high radiation flux conditions. Below the conducting material's ablation threshold the amount of ablation produced by the composite insulator is reduced by the reduction of insulator surface area exposed to the radiation. This allows better control of armature growth, mass acceleration by the plasma armature, secondary formation, and other factors normally found to retard projectile acceleration.

Abstract: The construction and arrangement of projectile bearing surface interfaces rearward and forward of a recessed surface chamber of the projectile interface conjointly with the interfaces of bore wall areas segmented by recessed bore chambers which in conjunction effect the deployment/transport/dispersement/development/modulation and transformation of explosive propellant charges sequentially primed and activated rearward and forwardly of the projectile along the bore and in bore wall chambers captively converting high static gas pressure to expansively relieved dynamic propellant gas pressure directly at the projectile reducing firearm barrel recoil while energizing projectile movement along the bore in a closed-system of thermodynamic propellant energy for free flight purposes.

Abstract: A method for propelling a projectile by applying a high power pulse of elrical current to a metal fuel element (of Al, Al-Li, or Al-Mg) causing the element to explode dispersing molten metal fuel into water with which it reacts to rapidly generate hydrogen gas at high pressure; the hydrogen gas is used to push the projectile. After the peak current is reached, an inductive electrical energy source drives the electrical current into the molten metal fuel/water mixture thus driving the reaction to completion.

Abstract: This disclosure relates to a plasma generation device particularly adapted to an electrothermal-chemical propulsion system. The device comprises a membranous conductive substance having structural compositions which enable the formation of a continuous and volumetrically distributed plasma arc. The membranous substance is versatile and operates, inter alia, as a fuse wire, plasma incubator, plasma container, plasma distributor, plasma infusion and permeation media as well as a fuel container.

Abstract: A compact bearing ball, or rail, gun to magnetically accelerate ferro-magnetic BBs is disclosed. The gun comprises a main board containing a channel sized to allow smooth passage of a BB, a straight portion of that channel forming a barrel terminating at an edge of the main board. A plurality of wire coils are disposed perpendicular to the axis of the barrel collinear with that axis. Driver circuitry for inducing in the plurality of wire coils is provided to ensure a synchronized generation of magnetic fields in individual ones of the wire coils to accelerate ferro-magnetic BBs disposed within the channel of the main board through the channel and out of the barrel. In a preferred embodiment, the channel has a loading segment substantially perpendicular to the barrel for aligning ferro-magnetic BBs prior to acceleration through the barrel, along with a magnet at the intersection of the loading segment and the barrel for positioning a BB co-centric with the axis of said barrel prior to acceleration.

Abstract: A method for propelling a projectile by applying a high power pulse of electrical current to a metal fuel element (of Al, Al--Li, or Al--Mg) causing the element to explode dispersing molten metal fuel into water with which it reacts to rapidly generate hydrogen gas at high pressure; the hydrogen gas is used to push the projectile. After the peak current is reached, an inductive electrical energy source drives the electrical current into the molten metal fuel/water mixture thus driving the reaction to completion.

Abstract: A cartridge for accelerating a projectile includes a light gas pressurized in a sealed container to 5,000-10,000 psi. Upon ignition in the sealed container, a gas mixture having a low or intermediate molecular weight and a high or low energy density is applied as a high sound speed gas to accelerate the projectile to speeds of above about 2.4 km/sec.

Abstract: A mass located in a track defined by a closed, continuous path is gradually and smoothly accelerated or decelerated by controlling movement of the track so a portion of the track where the mass is sensed to be located is moved inwardly (for acceleration) or outwardly (for deceleration) along a local radius of curvature of the track.

Abstract: An ignition tube for use with electrothermal chemical combustion ignition projectiles in guns, comprising a tube positionable in a combustion chamber for receiving plasma ignition from a plasma chamber. The tube is formed from high density polyethylene or other materials adapted to release plasma upon contact by plasma ignition electrical energy or pulses. The tube is specifically designed to provide an increasing exit area from the proximal end of the tube toward the distal so as to act upon the longitudinally attenuated plasma, thereby substantially decreasing the amplitude of any reflected shock in the plasma stream. The exit area comprises a plurality of radially extending orifices or holes that have a decreased angle of inclination to the longitudinal axis from proximal end to distal end, such that the orifices form a spiral pattern on the circumference of the tube. This pattern provides a uniform action of plasma on the propellant over the entire length of the ignition tube.

Abstract: A booster stage is positioned down-bore from the breech of a gun to contain a charge of liquid propellant that is ignited by the combustion gases of a detonated breech propellant charge trailing the projectile down the gun bore. The detonated liquid propellant increases the bore gas pressure and thus accelerates the projectile to a higher muzzle velocity.

Abstract: A high pressure pulsed gas source for accelerating a projectile along a gun barrel comprises a structure including a high voltage electrode for establishing axial electrical discharges in corresponding axial gaps behind an outlet where the projectile is located. Plasma flows at right angles to the discharges into a propellant mass that is converted into a high pressure component of the gas pulse. The gaps are arranged so that after the projectile moves away from its initial position and is in the barrel, power applied to the plasma via gaps close to the outlet is greater than power applied to the plasma via gaps farther from the outlet. To avoid damage to the gun, the gaps are arranged so power applied to the plasma is substantially the same in the discharges when plasma is initially produced. The gaps include walls that are eroded differently by the discharges so gap walls close to the outlet erode faster than gap walls farther from the outlet.

Abstract: A gun barrel has an erosion-reducing, electrically non-conductive lining extending along a length portion of the gun barrel. The lining is made of a polyimide.

Abstract: A method for accelerating projectiles comprises introducing the projectile into an accelerator barrel, feeding a combustible gas mixture into said barrel and igniting said mixture to accelerate the projectile, and is characterized in that a fluid is stored in the projectile and is ejected therefrom into the space between the projectile and the barrel. Suitable accelerator systems are disclosed.

Abstract: The present invention provides a propellant for electrothermal-chemical guns comprising a dispersion of one or more energetic solids in an energetic liquid phase. The energetic solid is preferably a nitramine such as cyclotrimethylenetrinitramine (RDX) and the energetic liquid component is preferably a homogeneous liquid that is either aqueous or non-aqueous. Aqueous liquid phases suitable for use in the present invention include concentrated solutions containing at least one nitrate salt. Non-aqueous liquid phases suitable for use include those that contain nitrate ester, nitramine, nitro or azido compounds or mixtures thereof.These propellants provide a high level of energy density because of the use of energetic ingredients and the high loading density allowed with a liquid propellant. The presence of a dispersed solid phase within the continuous liquid phase also permits control of the burning behavior of the propellant by variation of the interfacial area between phases.

Abstract: A gun barrel for a hybrid propellant/electrothermal gun has a first barrel portion; a second barrel portion axially separated from the first barrel portion; and an insulator unit forming a third barrel portion. The insulator unit connects the first and second barrel portions to one another and defines a plasma path. There is further provided an arrangement for placing the first barrel portion on a first electric potential and for placing the second barrel portion on a second electric potential. The first and second potentials are different from one another for generating, in the plasma path, an electric arc having an orientation parallel to the barrel axis for heating propellant gases which initially accelerate the projectile.

Abstract: A superconducting single phase alternator is connected by a circuit breaker across the breech ends of a pair of conductive launching rails. At a predetermined point on the alternator voltage wave a projectile establishes a current path between the rails to initiate a transient, sinusoidal current pulse effective in accelerating the projectile along the rails. A switch is actuated in response to the projectile exiting the muzzle ends of the rails to impose a short circuit across the rails. The circuit breaker disconnects the alternator from the rails as the current pulse goes to zero. The system provides higher launcher efficiency and reduced muzzle flash with minimum barrel length penalty.

Abstract: A sabot separator includes a sabot separation cylinder equipped with a pair of rail electrodes extending axially and connected with a muzzle end of a barrel of a projectile accelerator. An electrical power source is connected between the rail electrodes and applies a voltage to the rail electrodes for producing a force in a direction for decelerating the accelerating sabot. When the sabot enters the sabot separation cylinder, an electric current flows through the sabot and the sabot is suddenly stopped by a braking force resulting from the flow of the electric current.

Abstract: Apparatus is disclosed which provides coaxial connection between a high energy power supply and a plurality of plasma injectors in a gun breech assembly over a plurality of high energy transmission coaxial cables without losing the coaxial nature of the high energy transmission path at the connections between the coaxial cables and the plasma injectors. The apparatus includes a conductive bell housing for surrounding the connections while providing access for securing the connections with the bell housing in place.

Abstract: This disclosure relates to a method and device in which plasma arc is vectorally mobilized to ignite and create a moving burning propellant front such that high muzzle velocities are attained under low pressures. Primarily, electromagnetic forces are used to impart direction and velocity to an ionized conductive plasma arc mass in an electrothermal-chemical cartridge. The plasma arc mass is electromagnetically directed and accelerated through a combustion chamber and a gun tube thus imparting a traveling constant pressure and thrust behind a projectile to thereby yield very high muzzle velocities.

Abstract: This disclosure relates to a plasma generation device particularly adapted to an electrothermal-chemical propulsion system. The device comprises a membranous conductive substance having structural compositions which enable the formation of a continuous and volumetrically distributed plasma arc. The membranous substance is versatile and operates, inter alia, as a fuse wire, plasma incubator, plasma container, plasma distributor, plasma infusion and permeation media as well as a fuel container.

Abstract: An improved electromagnetic launcher (10; 98; 150) has a barrel (20; 100) formed by at least one pair of bus-bars (30, 32; 102, 104; 156, 158; 184, 184, 188, 190) to transport current longitudinally along the barrel. The barrel includes a bore (36; 108) which is spaced from the bus-bars by a bore structure (34; 106). The bore structure guides an elongated, tapered metal armature (44; 122; 164) through the bore. The current to the armature passes from the bus-bars through an array of deformable contactors (54, 55; 110, 112) disposed near the bore walls and in series with resistors (60, 62, 64, 66; 114, 116, 118, 120). The resistors distribute current and electromagnetic driving force along the armature. A conductive implodable shield (130) confines the bore structure and the bus-bars to impede repulsion of the bus-bars and to compress the magnetic flux between the shield walls and the bus-bars.

Abstract: An electrical power feed assembly (12) for supplying high current to an electrothermal gun has first and second electrical connectors (38) and (42) with associated contact portions (40) and (44) for engaging and plastically deforming first and second side contacts (20,22) on a cartridge (14) to provide firing while maintaining the electrical contact without any arcing. The first connector (38) has a curved contact portion (40) that provides an interference fit to plastically deform the first contact (20) and establish the electrical contact as the cartridge (14) is inserted into the gun. The second connector (42) has a pair of curved knife edges (48) that engage and plastically deform the second contact (22) of the cartridge to establish and maintain the electrical contact under spring action of the second connector and by operation of a cam mechanism (50) of a breech block (26) of the gun.

Abstract: A rapid fire electromagnetic launcher system (EML) employs a plurality of capacitor modules which are charged by an equal number of modules of lead acid batteries. The invention comprises the combination of standard automotive lead acid batteries for charging an electrolytic capacitor array which is switched into an Electromagnetic Launcher (EML) by means of silicon controlled rectifiers, and a control circuit for controlling the loading and launching of projectiles at a very rapid rate. The system includes a multishot preinjector and rapid fire controller for operating the system in a safe and reliable manner. The system includes a preaccelerator, magazine and barrel. The combination eliminates the low power density limitation of the batteries, the requirement to repetitively commutate energy out of an inductor, and allows for a modular system than can be expanded to provide higher energy to each projectile in the burst.

Abstract: Methods and apparatus related to design and construction of lightweight and mobile railgun barrels having high L' (inductance per unit length). The barrels comprise stacked metallic annular laminations in combination with prestressed tension elements to add radial and longitudinal stiffness. Laminations have elongated annular shapes to accommodate a plurality of longitudinal rails within the barrel, and the lamination shape is optimized to contain radial forces (tending to spread the rails) associated with the launching of railgun projectiles. Longitudinal stiffness is obtained from tension elements spirally wound around the barrel at a preferred angle with the barrel longitudinal axis. Radial stiffness is obtained by injecting a settable plastic fluid between barrel laminations and internal (bore) components, the latter being held as a subassembly with a longitudinal shrink tube.

Abstract: The serial arc plasma injectors device disclosed herein enables the formation of a segmented, isolated chain of plasma arcs which are incubated to form a specified energy level of plasma discharge tailored to initiate ignition and establish efficient combustion in a particular segment of a propellant mass. The device includes a capillary in which a conductive path comprising electrodes is maintained. Particularly, specialized electrodes provide geometric and dimensional flexibility to establish plasma arc and plasma discharge characteristics that are compatible with different zones of the propellant mass. The specialized electrodes in combination with discharge vents enable the development of a series of regions in the capillary through which plasma discharge is introduced into the propellant mass to selectively initiate ignition and promote efficient combustion.

Abstract: A device for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.

Abstract: An electrothermal chemical cartridge with a fuse of tapering cross section enables higher impulse energy to be imparted to a projectile by means of complete controlled burning of propellant. A long, narrow tube filled with propellant has a fuse on its inside surface with a cross section that tapers toward the discharge end, separated from the electrical ground of the cartridge casing by a layer of insulation sufficiently thin to be destroyed as the fuse ignites the propellant. A high-voltage electrode connected at the back end of the tube provides for application of a pulse of sufficient current density to ohmically heat or burn the fuse in a controlled fashion from the discharge end to the back end. Many such tubes can be bundled together in a large casing for wide barrel guns.

Abstract: A segmented electromagnetic launcher, comprising a solid rail (20) and a segmented rail (21), formed from segments (22a to 22z) with number of segments greater than one, isolated from one another. These two rails are positioned parallel to and spaced apart from one another, forming a barrel (3) with breech (4) and muzzle (5) ends for sliding a projectile with armature (23) inside the barrel. Two supply conductors (24a, 24b) are positioned on either side and parallel to the solid rail (20) and isolated from it; side supply conductors (25a to 25z, 26a to 26z) are positioned on either side of the bore of the barrel with the number of side supply conductors two times the number of the segments. Each segment (22k) is connected with two supply conductors (24a, 24b) by two side supply conductors (25k, 26k) in connection points (27a to 27z, 28a to 28z) located at the breech end of each segment.

Abstract: A pressurized light gas in a first chamber segment of a light gas gun is heated and highly pressurized by an electric discharge. Solid chemical propellant in a second chamber segment behind and separated from the first chamber segment by a perforated wall is ignited by the heated and highly pressurized light gas to form a gaseous piston to assist in accelerating the light gas against a projectile.

Abstract: The invention relates to an acceleration apparatus comprising an accelerator surrounding an acceleration path with the exception of at least its mouth-side end and an acceleration body which is configured for guided and accelerated motion along the acceleration path and is formed by a missile and preferably a propelling housing at least partially surrounding said missile and in engagement therewith.According to the invention, in the accelerator at least two rectilinear guide rails or guide grooves are formed which preferably have a mutual identical angular distance with respect to the bore axis and which are adapted to be brought into constrained engagement with the acceleration body directly and/or indirectly via at least one respective slide shoe on the acceleration body.

Abstract: In a two-stage railgun accelerating apparatus, a flying object is initially accelerated by acceleration gas produced by a gas gun. The initially accelerated flying object is led through an introducing pipe to an inlet of a railgun section of the two-stage railgun accelerating apparatus. A position and a velocity of the flying object are detected by a position detector and a velocity detector provided in the introducing pipe. According to the results of detection, both a voltage is applied to the railgun section and the acceleration gas is irradiated just behind the flying object with a laser beam, such that a dielectric breakdown of the gas is effected to generate plasma of good quality for accelerating the flying object.

Abstract: An electro-thermal gatling gun (12) includes a plurality of gun barrels (46) and a gun rotor (10) defining a plurality of channels (30). Each channel (30) guides a breechblock (32) between a rear position (50) and a breech position (52). Each said guide channel (30) is aligned with and rotatably fixed to one of the plurality of gun barrels (46). A cam guide (49) moves the breechblocks (32) reciprocally and in series from the rear position (50) to the breech position (52) as the gun rotor (10) rotates. An electro-thermal round (60) includes a projectile (62) and a casing (64) and is electrically connected to one of the breechblocks (32) when the breechblock (32) is in the breech position (52).

Abstract: The sabot (16) relates to a projectile (11) which can be accelerated in an accelerator comprising a tubular preaccelerator followed by RAM acceleration tubes. It consists of an outer band (18) which is designed in a way to be attached to the radial fins (13) at the rear of the projectile (11) and to support the peripheral sealing elements (25) and a subcaliber base plate (31) of relatively small thickness, which is designed in such a way that it rests on the outer band (18) with its perimeter, and if necessary on the projectile base (7) with its center part, and that it separates from the projectile (11) and the outer band (18) before the projectile (11) enters into the acceleration tubes.

Abstract: In a two-stage railgun accelerating apparatus, a flying object is initially accelerated by acceleration gas produced by a gas gun. The initially accelerated flying object is led through an introducing pipe to an inlet of a railgun section of the two-stage railgun accelerating apparatus. A position and a velocity of the flying object are detected by a position detector and a velocity detector provided in the introducing pipe. According to the results of detection, both a voltage is applied to the railgun section and the acceleration gas is irradiated just behind the flying object with a laser beam, such that a dielectric breakdown of the gas is effected to generate plasma of good quality for accelerating the flying object.

Abstract: Electromagnetic launcher apparatus which includes a set of conductive rails and a projectile having an armature which comprises both primary conductive material and phase changeable conductive material. This conducting, phase change material armature comprises material which when exposed to friction induced heat changes from solid to liquid form during the launching of projectiles along the conductive rails. This conducting, phase change material armature has decreased mass particularly useful for long barrel launches.

Abstract: An electromagnetically energized railgun system in which nesting and segmenting of the primary rails is combined with augmenting rails and crossover bar conductors and an inductorless single power supply arrangement to provide a high efficiency hypervelocity capable railgun improvement over prior railgun arrangements. The disclosed railgun apparatus uses a single power supply or energy source and achieves the desired near zero muzzle energy storage through a combination of inductive and resistive primary rail commutation, power supply pulsing, and augmenting rail inductive energy storage.

Abstract: An apparatus and method are provided for controlling the switching characteristics of an explosively actuated switch. The switch comprises a conductor that is only partially severed by explosive forces. A bridge region, the conductive portion of the conductor remaining after the explosion, is then severed by thermal breakdown. Variations in the bridge region enable a user to vary the switching characteristics of the switch.

Abstract: The method and apparatus disclosed herein relates to harnessing plasma to ignite, pressurize and distribute plasma, plasma-ignited chemical fluid and fuel throughout a propellant mass. Particularly, the present invention enables the creation of a progressive burning surface whereby the propellant reaches maximum pressure controllably and losses pressure much more slowly thus creating high piezometric efficiency. More particularly, in gun-charge-projectile systems, by using radial perforations designed to provide a balanced plasma discharge through a capillary wall and by developing forward accelerating thrust components, induced by the plasma pressure on a plasma-ignited chemical fluid and fuel mixture, the propelling charge travels down the gun tube with the projectile thus exerting substantial uniform pressure throughout the tube length and yielding a high ballistic efficiency which results in the attainment of high muzzle velocities.

Abstract: An electrothermal firing device (1) including a tube containing a charge chamber (4') in which a first electrode (9) is disposed at the end of the charge chamber (4') adjacent the breechblock (2) and a second electrode (10) is disposed at the end of the charge chamber adjacent the projectile (6). To permit the first electrode (9) adjacent the breechblock to be arranged in the charge chamber without expensive supports, in contrast to such prior art devices, this first electrode (9) is configured as the grounded electrode and the second electrode (10) is configured as the high voltage electrode. Preferably, the two electrodes (9, 10) are arranged in an exchangeable cartouche (18) so that conventional charge chambers employing corresponding loading devices can be retrofitted in a simple manner for use with electrothermal firing devices (1).

Abstract: A tube launched rocket system which uses a plurality of small propellant charges located within the tube to propel the rocket. The charges form part of the outer wall of a traveling propulsion chamber. The rest of the chamber is substantially defined by a propulsion housing, which includes a forward plate that abuts the projectile, and an aft nozzle for venting gases from the interior of the chamber. Alternative embodiments also contain baffles for directing the flow of combustion gases, and may employ an electronic ignition system for igniting the propellant charges in sequence. As charges adjoining the propulsion chamber are ignited, the resulting combustion gases thrust into the interior of the chamber, forcing the housing forward as they flow aftward through the nozzle. As the propulsion housing travels through the tube, additional propellant charges are ignited as they effectively become part of the outer wall of the propulsion chamber. The housing pushes the projectile ahead of it through the tube.

Abstract: A shock compression jet gun with associated explosive charge assembly. The shock compression jet gun features a breech for storage of the explosive charge assembly, a projectile tube, and an expansion nozzle disposed between the breech and projectile tube. The expansion nozzle includes converging and diverging passageways. The explosive charge assembly includes a shock absorbing outer casing, a detonator, a shaped charged positioned within the casing and a compressible medium retained within a recess formed in the shaped charge. The compressible medium is maintained within the recess by way of a membrane sealing one end of the casing. In a preferred embodiment the compressible medium is a liquid such as ammonia, water or a mixture of liquid ammonia and water which dissociate(s) into a mixture of light gases upon detonation of the shaped charge.

Abstract: A projectile propelling system includes a gun barrel filled with a gaseous propulsive mixture, a projectile having a front cone wall and a rear cone wall, and a driver for initially propelling the projectile in the gun barrel to an initial velocity above the detonation velocity of the gaseous propulsive mixture to produce a shock wave at the front cone wall followed by a detonation wave resulting from the reflection of the shock wave inside the barrel, which detonation wave is applied to the rear cone wall to increase the velocity of the projectile. The front cone wall and rear cone wall of the projectile are such as to create a "mach stem" in the form of a disc normal to the longitudinal axis of the projectile, of sufficiently high pressure and temperature to ensure ignition of the gaseous propulsive mixture.

Abstract: A device for connecting two tubes end-to-end. At least one of the tubes is movable longitudinally to be connected to the other tube. A screwthreaded nut joins the two tubes. The first tube has at its end an outside screwthread of diameter d1 and pitch p1. The second tube has at its end an inside screwthread of diameter d2 greater than d1 and pitch p2 different than that p1 of the first tube. One of the screwthreads is continuous and the other is discontinuous by virtue of longitudinal lands subtending an angle at the center of the tube equal to that of the screwthreaded longitudinal lands. The nut 3 has an inside first screwthread compatible with that of the first tube and an outside second screwthread compatible with that of the second tube. The device further includes a system for immobilizing the tubes against rotation and a system for rotating the nut.

Abstract: A railgun apparatus for accelerating a projectile having a conductive region. The railgun comprises a power supply for providing a current impulse and at least two elongate generally parallel rails. The rails include a first layer comprising a highly conductive material and a second layer comprising a highly resistive layer. The second layer has a resistivity that varies along the length of the rails and is so sized and arranged as to contact the conductive region of the projectile. The power supply is switchably connected to the first layer of the rails. When the current impulse is applied to the rails with the projectile therebetween, the current impulse is spread over the conductive region of the projectile to reduce the velocity skin effect.

Abstract: An electromagnetic accelerator arrangement includes a stationary arrangement including at least one stationary primary coil, and a movable arrangement including at least one moveable secondary coil. The planes of the stationary and the moveable coils are parallel to a direction of movement of the moveable arrangement. The coils of the stationary and the movable arrangements have approximately the same coil width in the direction of movement of the moveable arrangement and transversely thereto, as well as the same coil separation in the direction of movement of the moveable arrangement. The at least one stationary primary coil includes at least two layers between which the at least one secondary coil of the movable component is movably disposed, the distance between the layers being kept small transversely to the direction of movement of the moveable arrangement.

Abstract: The method and apparatus disclosed herein relates to a precision generator and distributor device for plasma and plasma discharge arc as it particularly applies to electro-thermal chemical gun system operations. A self-adjusting filament erodably controls the formation, energy content, consistency and dimension of a plasma arc in a capillary. Specifically, in cooperation with radially and longitudinally formed perforations in the capillary wall, the filament enables the distribution of a predetermined amount of plasma and plasma-ignited chemical fluid into segments and regions of a combustible chemical in a contiguous chamber to thereby control combustion and increase piezometric and ballistic efficiency of the gun system. More specifically, the filament enables the creation of a plasma arc that is sustainable, definite and consistent and one which yields high pressure and temperature at a reduced ohmic resistance for a given power supply.

Abstract: An augmented electromagnetic accelerator apparatus which imparts an initial elocity to a projectile by use of enhanced inductance gradients and allows for the use of cylindrical projectiles by the use of a round bore, using a parallel gun rail geometry The enhanced inductance gradients are achieved by the use of an extra turn around the gun rails and enclosing the rail and the said augmented turn in laminated iron. The augmented accelerator has crossovers at the two ends (breech and muzzle end) which have minimum influences over the electromagnetics in the bore of the accelerator.