FR2513824A1 - CO2 LASER CATALYSIS HERMETICALLY CLOSED - Google Patents

Abstract

THE INVENTION RELATES TO A HERMETICALLY CLOSED CO-CATALYST LASER. THIS LASER INCLUDES A FIRST AND A SECOND ELECTRODE 106, 108 ARRANGED IN A DISCHARGE ZONE CONTAINING AN AMPLIFICATION MEDIUM, AN ELEMENT INTENDED TO EXCITE THIS AMPLIFICATION MEDIA WITH AN ELECTRIC DISCHARGE AND AN ELEMENT INTENDED TO RESONATE THE RADIATION IN LASER THE DISCHARGE ZONE, AT LEAST ONE OF THE ELECTRODES 106, 108 INCLUDING AN INTERIOR PART WHICH CONTAINS A CATALYTIC MATERIAL AND WHICH COMMUNICATES WITH THE DISCHARGE ZONE THROUGH SEVERAL OPENINGS. THE INVENTION IS USED TO MAINTAIN CO PUREITY IN A LASER.

Description

C02 laser catalyzed hermetically closed.

  The technical field of the present invention

  is that of a CO laser, hermetically sealed.

  As has long been known in the art of C 02 lasers, an amplification medium

  electrically excited C 02 decomposes

  CO and oxygen, and the resulting products

  decontamination tend to suppress the

  The oxygen in such small quantities

  that 1% leads to an arc ignition between electro-

  of the laser with, as a consequence, a loss of

  A previously adopted approach to this problem has been to use a

  heated platinum in order to promote recombination

  CO 2 and oxygen to form CO 2 This process has the obvious disadvantages of requiring an additional source of energy to heat the wire

  platinum and also to increase the amount of

  their generated within the discharge volume of the

laser.

  Several tests have been undertaken to test the use of a catalyst at the

  ambient temperature, the materials used include

  activated copper, activated platinum and hopca-

  lite (commercial mixture of magnesium oxide, copper oxide and traces of other oxides) This material is marketed by the "Mine Safety Appliances Company" In an article by C Willis and JG Purdon published in the "Journal of Applied Physics ", Volume 50, No. 4, April 1979, describes the use of hopcalite in an outer gas loop connected to the active volume of a laser, but without the catalyst being present in this volume. Rudko and JW Barnie published in 1980 in "Proceedings of the SPIE", volume 227 and entitled "CO 2 Laser Devices and Applications", it is reported the application,

  successful, a solid catalyst at the

  ambient temperature inside a laser cavity, but without giving any details regarding the type of catalyst used and its arrangement in the aforementioned cavity According to this article, these details are

  covered by property rights.

  The present invention relates to a hermetically sealed CO 2 laser, in which gaseous CO 2

  is maintained in a state of purity by a solid catalyst

  at room temperature contained in a porous electrode. In the accompanying drawings, FIG. 1 illustrates one embodiment of the invention in which a catalyst in the form of solid pellets is used; and FIG. 2 is a cross section of a

  electrodes illustrated in FIG.

  FIG. 1 schematically illustrates a hermetically sealed laser constructed according to the invention. Cover plates 102 and 104 form two sides of the laser cavity. Electrodes 106 and 108 are shaped according to conventional elements to allow the passage of an electric discharge. through C 02 gas These electrodes are made

  according to a known configuration illustrated in the

  patent application N O FR 82 06898 mentioned here for

  reference and which describes a hermetic C 02 laser.

closed without catalyst.

  During commissioning, an electric discharge

  pulsed ring is generated between the electrodes 106 and

  108, which has the effect of exciting the ampli-

  C 02 and initialize the action of the laser.

  The electric discharge warms the C 02 gas

  interior of a confined space thereby raising the

2513824-

  A pressure pulse is then generated

  in the central area of the landfill and it is

  page quickly outward to equalize the

  pressure in the confined volume This impulse

  pressure pressure passes through the porous electrodes.

  its 106 and 108 by driving out some of the middle of am-

  C 02 plating through the holes in the electrodes and passing it from the laser cavity to the inside-of the electrodes This movement serves

  to circulate the gas and thus to bring the C 02 dissolving

  that is, CO and 0, inside the electro-

  Inside the electrodes, the gas goes into

  contact with a catalyst which, in the form of

  illustrated illustration, is in the form of pastil-

  the full 120, although we can also use

  apply a catalyst applied to a substrate if this

is convenient.

  A second mechanism for bringing gas

  dissociated in contact with the catalyst is the diffusion

  sion, which will take place even when the laser is

  not in service Since the products of dis-

  society that constitute 02 and CO, are primarily

  tially between the electrodes, they will tend to

  spread outward from their location

  initially, that is to say they will diffuse inside the electrodes 106 and 108 thus entering

in contact with the catalyst.

  The catalyst can be any catalyst

  well known such as platinum, activated copper or

  hopcalite, which tends to favor the recombination of

CO sound and O in C 02.

  In the illustration, sidewalls, mirrors, electrical discharge fittings and others

  components of the laser are omitted for reasons of simplicity

plicity and clarity.

  The electrodes illustrated in the drawing are made of a wire mesh having openings in the form of rectangular holes; however, the size and configuration of these openings are not critical to the invention. Any suitable form can be adopted

  opening, for example, circular holes, hexagonal

  gonaux or rectangular holes must not

  necessarily be evenly distributed over

  face of the electrode and they can be formed by

  any suitable means, mechanical or chemical.

  The size of the holes will obviously depend on the

  of the catalyst pellets, since

  It is desirable to maintain the catalyst particles

  outside the laser discharge zone

  exact dimensions of the holes and particles of

  will depend on the particular application envisaged

  specially, the amount of energy con-

  nude in the laser discharge and, hence, the

  study of the generated pressure pulse If the

  The catalyst particles are sufficiently light to be set in motion during the pressure impulse, and the invention has the additional advantage that the surface of the catalyst is subjected to

  constant rotation, which enables it to be uniformly

  ance. Although the subject of the invention is a hermetically sealed laser, it can also be applied to

  for example, a gas laser in circulation

  could be used to circulate a gas

  through the electrode 106 and pass it through a

  outer key, with return through the electrode 108, thereby effectively exposing the gas to the catalyst, while

  retaining one of the main advantages of the invention

  to obtain a laser having a compact active volume by using the electrodes

containing the catalyst.

  The possibility of producing wire electrodes (without catalyst) has been previously demonstrated in a report by LJ Denes, entitled "Ultraviolet Initiated Co 2 Laser Research, Phase II",

  Report No. AFWL-TR-76-136, January 1977.

  In this embodiment, a "TEA" laser is used, as described in the aforementioned patent application No. FR 82 06898, but the type of excitation, the

  type of ionization and the laser pressure does not relate to

  not to the present invention which relates to the use

  of catalysts at room temperature at room temperature.

inside a porous electrode.

Claims (4)

  A C 02 laser comprising: a first and a second electrode arranged   in a discharge zone containing an amplification medium   fication; an element for exciting this amplification medium with an electric discharge; and   an element intended to resonate the   in the discharge zone, characterized in that   at least one of the first and second electrodes   takes an inner part containing a material   said inner portion communicating with the discharge zone by means of a plurality of openings defined between said inner portion and said discharge area.   Laser according to claim 1, characterized   in that the catalytic material is in the form of solid granular particles freely the inner part.   Laser according to claim 1, characterized   in that the catalytic material is arranged on   along several substrates placed in the inte- pool.   4 Laser according to any one of the claims   cations 1 to 3, characterized in that the openings   cited are defined by the interstices of a canvas   metal part of the aforementioned electrode.   Laser according to one of Claims 1 to 3, characterized in that the apertures   are mechanically formed in a predefined part born from the aforementioned electrode.