Improvements in or relating to lasers
Apparatus is described for producing and utilizing electrons in a selected energy range, employing a new type of laser. The laser described comprises a gas discharge device containing an anode and a cathode, together with at least one apertured structure in the discharge path so as to produce a double sheath'' and plasma sac,'' together with a pair of mirrors for forming a laser beam through the plasma sac,'' the beam being formed by excitation of atoms by the high energy electrons in the plasma sac.'' The anode and cathode may be cylindrical, and the mirrors arranged so that the laser beam passes through the anode and cathode. The gas discharge device may comprise a tubular container, with Brewster windows in the container wall, with the mirrors outside the container. The double sheath'' consists of a double space charge layer formed at the junction between two plasmas (see Proc. Roy. Soc. Lond.; A320: 459(1971)), and contains a voltage step such that the force exerted on electrons is in the opposite direction to that on the ions. The total voltage drop across the double sheath'' depends on the plasma conditions on either side and the electrons gain energy as they cross the boundary from the cathode to the anode side. Ways of creating the difference between the two plasma conditions required to produce the double sheath'' are described, including the introduction into the gas discharge column of a constriction in the form of an apertured structure extending across the electron path between cathode and anode. The double sheath'' developed over the cathode side of the constriction controls the flow of electrons and ions through the constriction, and the electric field inside the double sheath'' accelerates electrons from the cathode plasma into a plasma sac,'' which is a light blob of plasma protruding out of the constriction into the cathode section of the gas discharge device. Ions from the plasma sac,, are accelerated in the opposite direction, from the plasma sac'' into the cathode plasma. By using this arrangement to accelerate electrons it is possible to produce electrons in a selected energy range with a very high flux. This arrangement is used to provide electrons in a selected energy range to form a laser, the electrons being used for the excitation of atoms to the appropriate energy level to provide laser action, and it is possible using this technique to obtain a laser with high electrical efficiency. Such lasers work at a power level far above the powers of present lasers. The electron flux energy produces light energy from a radiationproducing excitation-relaxation reaction, this light energy being built up by the laser action with multiple reflection between the mirrors. (UK)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-29-025819
- OSTI ID:
- 4344603
- Report Number(s):
- GB 1338217
- Resource Relation:
- Patent File Date: 1969 Aug 11; Other Information: Orig. Receipt Date: 30-JUN-74; Bib. Info. Source: UK (United Kingdom (sent to DOE from))
- Country of Publication:
- United Kingdom
- Language:
- English
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