Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/02—Constructional details
  • H01S3/03—Constructional details of gas laser discharge tubes
  • H01S3/0305—Selection of materials for the tube or the coatings thereon
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/02—Surface treatment of glass, not in the form of fibres or filaments, by coating with glass
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/06—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals
  • C03C17/10—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals by deposition from the liquid phase
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
  • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
  • H01J5/08—Vessels; Containers; Shields associated therewith; Vacuum locks provided with coatings on the walls thereof; Selection of materials for the coatings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/30—Vessels; Containers
  • H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
  • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel

Definitions

• ABSTRACT OF THE DISCLOSURE A sodium-vapor lamp having an envelope, the inner wall of which is porous, the pores of the wall opening out at the surface being free of any material and preferably communicating with one another which minimizes selective absorption of the rare gases used in starting the lamp.
• the invention relates to an envelope of a gas discharge tube, particularly of a gas discharge tube in which a mixture of two or more rare gases is provided.
• Such a discharge tube is for example a sodium-vapor discharge lamp, in which the gas filling serves for igniting the lamp.
• the gas filling required for the ignition consists of a mixture of rare gases, for example 99% of neon and 1% of argon.
• Such a mixture of rare gases has a considerably lower ignition voltage than a single rare gas, for example neon.
• the total rare-gas pressure is chosen as low as possible, since the cmissive output of the lamp decreases rapidly with an increasing pressure.
• Such discharge lamps involve the ditficulty that the envelope selectively absorbs argon so that after some time only neon is left. This results in the ignition voltage becoming considerably higher and the lamp can no longer be ignited by the stabilization apparatus provided.
• a class of borate glass compositions having only a very small degree of argon absorption and having no tendency to color due to the contact with sodiumvapor.
• These borate glasses have very slight chemical resistivity and can therefore be used only as the inner coating of chemically resistant supporting envelopes. The manufacture of a two-layer envelope requires a special drawing technique and therefore special craftsmanship.
• the difficulty of the selective rare-gas absorption from a mixture also arises in gas lasers, for example lasers having a quartz envelope containing a mixture of helium and neon, the neon being absorbed by the quartz envelope.
• the envelope of a gas discharge tube of a glass known for this purpose is characterized according to the invention in that the envelope is coated on the inner side with a layer of porous material, the pores opening out at the surface and being preferably in communication with each other.
• the discharge is, as a rule, essential and without discharge no noticeable absorption occurs at the operational temperature (a few hundred degrees Centigrade).
• argon ions Owing to the difference in movability of electrons and rare-gas ions, for example, argon ions, during the discharge a potential difference between the glass surface and the positive column of the gas discharge is produced. This potential difference results in that positively charged ions, for example argon ions are absorbed in the glass wall, where they recombine with electrons, the ionization energy being released, for example with argon 15.68 ev.
• the absorbed gas may disappear from the surface layer by diffusion further into the glass and by desorption, especially thermal desorption, so that it can again take part in the discharge.
• the envelope when the envelope is provided on the inner side with a layer of porous material the pores opening out at the surface and preferably communicating with each other, the desorption becomes comparatively much greater than the absorption.
• the conditions are apparently such that, since in such a porous layer an absorbed gas atom after diffusion through the solid substance soon reaches again a boundary, the statistical possibility of desorption is strongly increased as compared with that of absorption.
• the material of the porous layer should be such that it is not colored by the sodium vapor.
• the glass below said porous layer is slightly protected by the porous layer from the attack of alkali vapor.
• the invention will be described more fuly with reference to the following experiments.
• the experiments were carried out on a sodium vapor discharge tube, the tubular envelope of which had a length of 30 cms. and an inner diameter of 13 mms. After the electrodes had been sealed in, the tube and the electrodes were degassed by heating in vacuo at 400 C.; then the glas surface and the electrodes were cleaned by burning the lamp with a filiing of pure neon.
• the final gas filling consisted of a mixture of 98.9% of Ne and 1.1% of A at a pressure of 9 torr.
• the ready gas discharge tubes were burnt for a few hours with a current density of 0.41 A./cm.
• the argon absorption was measured by mass spectrometry. Moreover, the argon absorption was measured by determining the ratio of the intensity of a group of lines of the argon spectrum I (3850-4530 A.) and the neon spectrum I (5850-7200 A.) by means of suitable filters (Ilford color filters 601 and 608").
• the material of the envelope was the lime glass desig' B303 A120 MgO C80 B30 N830 K20 Glass SiOz (1)
• a glass envelope of a sodium-vapor discharge tube containing a mixture of two or more rare gases characterized in that the entire inner side of the envelope has a layer of porous material, the pores opening out at the surface being free of material other than said gases and preferably communicating with each other whereby selective absorption by the glass of the envelope of one of the gases is minimized.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Electromagnetism (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Plasma & Fusion (AREA)
• Optics & Photonics (AREA)
• Vessels And Coating Films For Discharge Lamps (AREA)
• Pipeline Systems (AREA)
• Discharge Lamp (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19792057

Family Applications (1)

Country Status (10)

Cited By (2)

Families Citing this family (2)

Citations (1)

• 1965
  • 1965-01-07 NL NL6500111A patent/NL6500111A/xx unknown
  • 1965-12-10 US US513081A patent/US3379302A/en not_active Expired - Lifetime
• 1966
  • 1966-01-04 CH CH7166A patent/CH443488A/de unknown
  • 1966-01-04 GB GB311/66A patent/GB1130321A/en not_active Expired
  • 1966-01-04 SE SE115/66A patent/SE308759B/xx unknown
  • 1966-01-04 DE DE19661539481 patent/DE1539481A1/de active Pending
  • 1966-01-04 AT AT5666A patent/AT256252B/de active
  • 1966-01-05 ES ES0321475A patent/ES321475A1/es not_active Expired
  • 1966-01-06 FR FR45047A patent/FR1462912A/fr not_active Expired
  • 1966-01-06 BE BE674803D patent/BE674803A/xx unknown

Patent Citations (1)

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