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US4164654A Expired / Lapsed US ⏱️ 0.0 years remaining

Device for generating an atomic cloud

Assignee: South African Inventions Development Corp
•
Filing: 1978-02-14
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Granted: 1979-08-14
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Expires: 1998-02-14
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Abstract

Abstract This invention relates to a device for generating an atomic cloud, the device having a housing in which is housed a cathode and an anode, and with suitable passages or flow directing members to direct flow of a gas outwardly away from or past the cathode discharge surface, so that when a suitable potential is applied across the anode and the cathode a glow discharge occurs between the anode and the cathode. The flow of gas preferably draws atoms that are ejected from the cathode discharge surface away from the cathode to a region beyond the cathode glow region, thereby to generate an atomic cloud having a low value of inherent radiation. The device is further incorporated with an apparatus for spectro-scopically analyzing a substance by fluorescent techniques.

Inventors

  • 👤 Louis R. P. Butler
  • 👤 Hendrik G. C. Human

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 00:53
CPC Classifications
H; H05; H05H; H05H3/00; H05H3/02; H05H1/00; H05H1/24; H05H1/4697

Claims Analysis

Total Claims: 36
Claim 1
Independent Claim 158 words
A device for generating an atomic cloud comprising, a housing having an inlet and an outlet port through which a gas may be introduced into and removed from the housing; a cathode having a discharge surface located within the housing; an anode also located within the housing, spaced from and electrically insulated from the cathode and located such that a discharge may occur between the discharge surface of the cathode and the anode; means for connecting a suitable potential across the anode and cathode for causing a glow discharge between the anode and cathode discharge surface thereby to eject atoms from the cathode discharge surface; and gas flow directing means for directing a flow of the gas from the inlet port outwardly away from or past the cathode discharge surface, said gas flow directing means comprising means for causing the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 2
Independent Claim 158 words
A device for generating an atomic cloud comprising, a housing having an inlet and an outlet port through which a gas may be introduced into and removed from the housing; a cathode having a discharge surface located within the housing; an anode also located within the housing, spaced from and electrically insulated from the cathode and located such that a discharge may occur between the discharge surface of the cathode and the anode; means for connecting a suitable potential across the anode and cathode for causing a glow discharge between the anode and cathode discharge surface thereby to eject atoms from the cathode discharge surface; and gas flow directing means for directing a flow of the gas from the inlet port outwardly away from or past the cathode discharge surface, said gas flow directing means comprising means for causing the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 3
Dependent Claim 31 words
A device as claimed in claim 1, in which the gas flow directing means is such that the gas is caused to flow past the periphery of the cathode discharge surface.
Claim 4
Dependent Claim 29 words
A device as claimed in claim 2, in which the gas flow directing means comprises a hollow gas flow constraining element, the cathode being located within the constraining element.
Claim 5
Dependent Claim 20 words
A device as claimed in claim 3, in which the gas flow constraining element is of an electrically insulating material.
Claim 6
Dependent Claim 44 words
A device as claimed in claim 1, in which the cathode has a passage which has its outlet opening in the cathode discharge surface and the gas flow directing means causes the gas to flow through the passage and out through its outlet opening.
Claim 7
Dependent Claim 15 words
A device as claimed in claim 1, in which the cathode discharge surface is planar.
Claim 8
Dependent Claim 15 words
A device as claimed in claim 1, in which the cathode discharge surface is dished.
Claim 9
Dependent Claim 24 words
A device as claimed in claim 1, in which, in use, a normal glow discharge occurs between the anode and the cathode discharge surface.
Claim 10
Dependent Claim 24 words
A device as claimed in claim 1, in which, in use, an abnormal glow discharge occurs between the anode and the cathode discharge surface.
Claim 11
Dependent Claim 16 words
A device as claimed in claim 1, in which the housing has at least two windows.
Claim 12
Dependent Claim 28 words
A device as claimed in claim 10, in which the windows are located on optical axes that are mutually orthogonally disposed and which intersect in the operative region.
Claim 13
Dependent Claim 38 words
A device as claimed in claim 11, which includes a region having a low reflectivity disposed on the optical axis of one of the windows on the opposite side of the said operative region to the said window.
Claim 14
Dependent Claim 15 words
A device as claimed in claim 1, in which there is more than one cathode.
Claim 15
Dependent Claim 15 words
A device as claimed in claim 13, in which the cathodes have different chemical compositions.
Claim 16
Dependent Claim 20 words
A device as claimed in claim 1, in which at least a portion of the cathode is easily replaceably removable.
Claim 17
Dependent Claim 20 words
A device as claimed in claim 1, in which the housing is electrically insulated from the anode and the cathode.
Claim 18
Dependent Claim 14 words
A device as claimed in claim 1, in which the anode is a pin.
Claim 19
Dependent Claim 20 words
A device as claimed in claim 1, in which the anode is to one side of the cathode discharge surface.
Claim 20
Dependent Claim 45 words
A device as claimed in claim 1, in which the cathode is cylindrical, the gas flow directing means being adapted to direct the flow of the gas along the cylindrical wall(s) of the cathode past an end wall thereof which constitutes the cathode discharge surface.
Claim 21
Dependent Claim 15 words
A device as claimed in claim 1, in which the gas is an inert gas.
Claim 22
Dependent Claim 33 words
A device as claimed in claim 1, in which the cathode has an internal passage through which the gas is introduced into the housing, the cathode or cathodes thereby constituting the inlet port.
Claim 23
Independent Claim 167 words
An apparatus for spectroscopically analysing a substance, which includes a device for generating an atomic cloud comprising a housing having an inlet and an outlet port through which a gas may be introduced into and removed from the housing; a cathode having a discharge surface located within the housing; an anode also located within the housing, spaced from and electrically insulated from the cathode and located such that a discharge may occur between the discharge surface of the cathode and the anode; means for connecting a suitable potential across the anode and cathode for causing a glow discharge between the anode and cathode discharge surface thereby to eject atoms from the cathode discharge surface; and gas flow directing means for directing a flow of the gas from the inlet port outwardly away from or past the cathode discharge surface, said gas flow directing means comprising means for causing the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 24
Independent Claim 167 words
An apparatus for spectroscopically analysing a substance, which includes a device for generating an atomic cloud comprising a housing having an inlet and an outlet port through which a gas may be introduced into and removed from the housing; a cathode having a discharge surface located within the housing; an anode also located within the housing, spaced from and electrically insulated from the cathode and located such that a discharge may occur between the discharge surface of the cathode and the anode; means for connecting a suitable potential across the anode and cathode for causing a glow discharge between the anode and cathode discharge surface thereby to eject atoms from the cathode discharge surface; and gas flow directing means for directing a flow of the gas from the inlet port outwardly away from or past the cathode discharge surface, said gas flow directing means comprising means for causing the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 25
Independent Claim 128 words
A method of spectroscopically analysing a substance, comprising the steps of providing a device for generating an atomic cloud which has an anode and a cathode having a discharge surface, said anode and cathode being located within a gas-tight housing; applying a potential across the anode and the cathode sufficient to cause a glow discharge between the anode and the cathode discharge surface thereby to eject atoms from the cathode discharge surface; and directing a gas flow outwardly away from or past the discharge surface to cause the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region; irradiating the atomic cloud with radiation emitted by the substance; and detecting the amount of fluorescent radiation emitted by the atomic cloud.
Claim 26
Independent Claim 128 words
A method of spectroscopically analysing a substance, comprising the steps of providing a device for generating an atomic cloud which has an anode and a cathode having a discharge surface, said anode and cathode being located within a gas-tight housing; applying a potential across the anode and the cathode sufficient to cause a glow discharge between the anode and the cathode discharge surface thereby to eject atoms from the cathode discharge surface; and directing a gas flow outwardly away from or past the discharge surface to cause the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region; irradiating the atomic cloud with radiation emitted by the substance; and detecting the amount of fluorescent radiation emitted by the atomic cloud.
Claim 27
Independent Claim 106 words
A method of generating an atomic cloud, comprising the steps of providing a device for generating an atomic cloud which has an anode and a cathode having a discharge surface, said anode and cathode being located within a gas-tight housing; applying a potential across the anode and the cathode sufficient to cause a glow discharge between the anode and the cathode discharge surface thereby to eject atoms from the cathode discharge surface; and directing a gas flow outwardly away from or past the discharge surface to cause the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 28
Independent Claim 106 words
A method of generating an atomic cloud, comprising the steps of providing a device for generating an atomic cloud which has an anode and a cathode having a discharge surface, said anode and cathode being located within a gas-tight housing; applying a potential across the anode and the cathode sufficient to cause a glow discharge between the anode and the cathode discharge surface thereby to eject atoms from the cathode discharge surface; and directing a gas flow outwardly away from or past the discharge surface to cause the ejected atoms to move away from the cathode discharge surface to a region beyond the cathode glow region.
Claim 29
Dependent Claim 16 words
A method as claimed in claim 24, in which the discharge is a normal glow discharge.
Claim 30
Dependent Claim 16 words
A method as claimed in claim 24, in which the discharge is an abnormal glow discharge.
Claim 31
Dependent Claim 23 words
A method as claimed in claim 24, in which the gas is caused to flow past the periphery of the cathode discharge surface.
Claim 32
Dependent Claim 40 words
A method as claimed in claim 24, in which the cathode has a passage which has its outlet opening in the cathode discharge surface and the gas is caused to flow through the passage and out through the outlet opening.
Claim 33
Dependent Claim 15 words
A method as claimed in claim 24, in which the gas is an inert gas.
Claim 34
Dependent Claim 34 words
A method as claimed in claim 24, in which the flow of gas is at a suitable rate to ensure a suitable pressure in the space between the anode and the cathode discharge surface.
Claim 35
Dependent Claim 21 words
A method as claimed in claim 24, in which the potential difference between the anode and the cathode is maintained constant.
Claim 36
Dependent Claim 21 words
A method as claimed in claim 24, in which the discharge current between the anode and the cathode is maintained constant.

References Cited (Backward Citations)

US2636990A Cited
US2785311A Cited
US2806161A Cited
US3265890A Cited
US3457407A Cited
US3409529A Cited
US3849656A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-08-13 1983-02-12 1983-08-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-08-13 1987-02-12 1987-08-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-08-13 1991-02-12 1991-08-14 $7700.00 Window Closed / Lapsed

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