Electromagnetic device and method to accelerate solid metal slugs to high speeds

Patent metadata

Field	Value
Publication number	US-9534863-B2
Application number	US-201213662786-A
Country	US
Kind code	B2
Filing date	Oct 29, 2012
Priority date	Nov 1, 2011
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A device and method to accelerate solid metal slugs to high speeds. In one embodiment, a large electric current is passed through an outer cylindrical metal tube enclosing in part a metal slug, a central electrode, and a conducting tail coupled at opposite ends to the. metal slug and the central electrode. Electromagnetic forces accelerate the metal slug to a point high enough to mechanically separate the conducting tail. On separation, a plasma is generated by the passage of electric current though a gas produced by vaporization of the conducting tail and nearby materials. An insulator enclosed within the tube prevents the plasma from shorting to the outer tube until the current flow has produced a sufficient magnetic field to contain the plasma. The metal slug is then accelerated to high speed by a combination of electromagnetic forces and mechanical pressure from the hot gas through which the electric current is passing.

First claim

What is claimed is:

1. A tubular electromagnetic (EM) launcher device for accelerating solid metal slugs to high speeds comprising:
a cylindrical metal tube having an outer diameter and an inner diameter and having a tube wall between said outer diameter and said inner diameter, where said tube wall surrounds a central channel having a central axis;
a metal slug disposed within said central channel and in conductive contact with said tube wall, where said central axis of said central channel intersects said metal slug;
a central electrode disposed within said central channel where said central electrode is displaced from said tube wall;
a conducting tail where said conducting tail is displaced from said tube wall, where a first portion of said conducting tail is attached within said metal slug and in conductive contact with said metal slug, a second portion of said conducting tail extends between said metal slug and said central electrode, and a third portion of said conducting tail extends within said central electrode and is in conductive contact with said central electrode, and where said central axis of said central channel intersects said first portion of said conducting tail, said second portion of said conducting tail, and said third portion of said conducting tail;
a first conductive plate in conductive contact with said central electrode; and,
a second conductive plate in conductive contact with said cylindrical metal tube,
wherein application of a current to said metal tube through said second conductive plate results in said current passing through said cylindrical metal tube, through said metal slug, through said conducting tail, and through said central electrode causing said conducting tail to break with resultant generation of a plasma along said central axis of said central channel and generation of gas pressure,
and further wherein said current passes through said plasma producing an axial magnetic field which encircles said plasma and inhibits flow of said plasma said cylindrical metal tube resulting in said plasma formed as a plasma channel displaced from said tube wall;
and further wherein said current passes through said plasma producing an electromagnetic force wherein said gas pressure and said electromagnetic force accelerate said metal slug to a high speed greater than or equal to 1000 m/s.

2. The tubular electromagnetic (EM) launcher device of claim 1 wherein said metal slug further comprises:
one or more conducting extensions.

3. The tubular electromagnetic (EM) launcher of claim 1 where some portion of said central electrode surrounds a portion of said central axis, and where said third portion of said conducting tail is in conductive contact with said central electrode at said some portion of said central electrode.

4. The tubular electromagnetic (EM) launcher of claim 3 further comprising an insulator disposed within said central channel where said insulator surrounds said portion of said central axis and separates said tube wall and said some portion of said conducting central electrode.

5. The tubular electromagnetic (EM) launcher of claim 1 further comprising said current passing through said cylindrical metal tube, through said metal slug, through said conducting tail, and through said conducting central electrode, wherein said current causes said metal slug to accelerate and the acceleration of said metal slug causes said conducting tail to break.

6. The tubular electromagnetic (EM) launcher of claim 5 where said current causes said metal slug to accelerate and the acceleration of said metal slug causes said conducting tail to break into a first half attached within said metal slug and a second half in conductive contact with said conducting central electrode, and said current causes a plasma arc to form between said first half and said second half.

7. A method for accelerating solid metal slugs to high speeds in a device comprising:
a cylindrical metal tube having an outer diameter and an inner diameter and having a tube wall between said outer diameter and said inner diameter, where said tube wall surrounds a central channel having a central axis;
a metal slug disposed within said central channel and in conductive contact with said tube wall, where said central axis of said central channel intersects said metal slug;
a central electrode disposed within said central channel where said central electrode is displaced from said tube wall;
a conducting tail where said conducting tail is displaced from said tube wall, where a first portion of said conducting tail is attached within said metal slug and in conductive contact with said metal slug, a second portion of said conducting tail extends between said metal slug and said central electrode, and a third portion of said conducting tail extends within said central electrode and is in conductive contact with said central electrode, and where said central axis of said central channel intersects said first portion of said conducting tail, said second portion of said conducting tail, and said third portion of said conducting tail;
a first conductive plate in conductive contact with said central electrode;
a second conductive plate in conductive contact with said cylindrical metal tube, said method comprising:
applying a current to said cylindrical metal tube through said second conductive plate resulting in said current passing through said metal tube, through said metal slug, through said conducting tail, and through said central electrode causing said conducting tail to break with resultant generation of a plasma along said central axis of said central channel and generation of gas pressure,
passing said current through said plasma producing an axial magnetic field which encircles said plasma and inhibits flow of said plasma to said cylindrical metal tube resulting in said plasma formed as a plasma channel separated from said tube wall;
and further wherein said current passes through said plasma producing an electromagnetic force wherein said gas pressure and said electromagnetic force accelerate said metal slug to a high speed greater than or equal to 1000 m/s.

8. The method of claim 7 where the causing of said conductive tail to break comprises accelerating said metal slug sufficiently to mechanically separate said conducting tail and causing said conducting tail to break into a first half attached within said metal slug and a second half in conductive contact with said conducting central electrode, and where the resultant generation of said plasma comprises forming a plasma are between said first half attached within said metal slug and said second half in conductive contact with said conducting central electrode.

9. A system for accelerating solid metal slugs to high speeds comprising:
a cylindrical metal tube having an outer diameter and an inner diameter and having a tube wall between said outer diameter and said inner diameter, where said tube wall surrounds a central channel having a central axis;
a metal slug disposed within said central channel and in conductive contact with said tube wall, where said central axis of said central channel intersects said metal slug;
a conducting central electrode disposed within said central channel where said conducting central electrode is displaced from said tube wall and where some portion of said conducting central electrode surrounds a portion of said central axis, and where said conducting central electrode is disposed within said central channel such that said tube wall surrounds said some portion of said conducting central electrode;
a single conducting tail where said single conducting tail is displaced from said tube wall, and where a first portion of said conducting tail is attached wit

Assignees

• Us Navy

Inventors

• Maier William Bryan
• Nolting Eugene Ellis
• Morris Gene
• Snyder Donald D
• Caramico George Ralph

Classifications

• F42B6/006

  Projectiles for electromagnetic or plasma guns · CPC title

• F41B6/00

  Electromagnetic launchers {; Plasma-actuated launchers (projectiles for electromagnetic or plasma guns F42B6/006)} · CPC title

• F41B6/006 Primary

  Rail launchers · CPC title