Abstract: An ultra-low or very low frequency communication device composed of: a circuit unit operative to produce an alternating current; and a dipole antenna connected to receive the alternating current and to convert the alternating current into electromagnetic radiation. The antenna is composed of an unshielded radiating conductor and a shielded return conductor connected in series with the radiating conductor, and the return conductor is shielded by a Faraday shield such as a collisionless plasma column that surrounds the return conductor to prevent any electromagnetic radiation from the return conductor.

Abstract: An ultra-low or very low frequency communication device composed of: a circuit unit operative to produce an alternating current; and a dipole antenna connected to receive the alternating current and to convert the alternating current into electromagnetic radiation. The antenna is composed of an unshielded radiating conductor and a shielded return conductor connected in series with the radiating conductor, and the return conductor is shielded by a Faraday shield such as a collisionless plasma column that surrounds the return conductor to prevent any electromagnetic radiation from the return conductor.

Abstract: An explosive device composed of an auxiliary flux compression generator operating to produce a high intensity magnetic field to seed a primary flux compression generator The auxiliary flux compression generator has a first section with a magnetic field supplied by a cylindrical permanent magnet array, the first section is composed of a helical winding having a prescribed pattern configured to convert explosive energy into magnetic energy that will be used as seed magnetic field for the primary flux compression generator.

Abstract: An ultra-low or very low frequency communication device composed of: a circuit unit operative to produce an alternating current; and a dipole antenna connected to receive the alternating current and to convert the alternating current into electromagnetic radiation. The antenna is composed of an unshielded radiating conductor and a shielded return conductor connected in series with the radiating conductor, and the return conductor is shielded by a Faraday shield such as a collisionless plasma column that surrounds the return conductor to prevent any electromagnetic radiation from the return conductor.

Abstract: An explosive device composed of an auxiliary flux compression generator operating to produce a high intensity magnetic field to seed a primary flux compression generator The auxiliary flux compression generator has a first section with a magnetic field supplied by a cylindrical permanent magnet array, the first section is composed of a helical winding having a prescribed pattern configured to convert explosive energy into magnetic energy that will be used as seed magnetic field for the primary flux compression generator.

Abstract: A plasma generator composed of a body of electrically conductive, ionizable material connected to conduct a current pulse and to be converted into a plasma that occupies a large volume in the ionosphere. A plasma generating system composed of a source of a high intensity current pulse and the plasma generator.

Abstract: An ultra-low or very low frequency communication device composed of: a circuit unit operative to produce an alternating current; and a dipole antenna connected to receive the alternating current and to convert the alternating current into electromagnetic radiation. The antenna is composed of an unshielded radiating conductor and a shielded return conductor connected in series with the radiating conductor, and the return conductor is shielded by a Faraday shield such as a collisionless plasma column that surrounds the return conductor to prevent any electromagnetic radiation from the return conductor.

Abstract: An explosive device composed of: a flux compression generator operative to produce a high intensity electric current when activated; and an electrical payload connected to the generator and constructed to receive the high intensity electric current and cause energy in the current to generate a shaped projectile in the payload and to launch the projectile.

Abstract: A gun system for launching a projectile that forms a component of a two-part payload that also includes a pusher that is separable from the projectile. The system includes a barrel, a source of propellant gas to propel the projectile and the pusher through the barrel, and a retarding coil and an accelerating coil, each having a coil axis parallel to the barrel axis and surrounding a projectile passage through the barrel, the retarding coil being disposed closer to the source of propellant gas than the accelerating coil. The retarding coil is configured to generate electromagnetic energy in response to passage of the pusher when being propelled by propellant gas ignition, and the accelerating coil is configured and coupled to impose an accelerating force on the projectile in response to the electromagnetic energy generated by the retarding coil.