Patent US3852596A successfully refreshed from Google Patents.
US3852596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold cathode gaseous discharge device for producing electrons in an x-ray fluorescence analysis apparatus
Assignee: US Philips Corp
•
Filing: 1973-03-07
•
Granted: 1974-12-03
•
Expires: 1993-03-07
Abstract
Abstract Examination of the composition of a preparation by means of Xray fluorescence is difficult in the case of elements of lighter weights. An improvement is achieved by causing the preparation to produce X-rays from the lighter-weight elements by the bombardment of slow electrons, produced in a gas discharge, the cold cathode and the preparation space forming an equipotential space. Gas released from the preparation then has little influence.
Inventors
- 👤 E Houtman
- 👤 J Siekman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:48
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/0005; C11D3/0052; C11D3/16; C11D3/38; C11D3/386; C11D3/38672; C11D7/00; C11D7/02; C11D7/04; C11D7/10; C11D7/12; C11D7/22; C11D7/26; C11D7/265; C11D7/267; G; G01; G01N; G01N23/00; G01N23/22; G01N23/223; H; H01; H01J; H01J35/00; H01J35/02; G01N2223/00; G01N2223/07; G01N2223/076
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
186 words
Apparatus for causing X-ray fluorescence of the surface of a material, comprising: walls defining a first chamber, a second chamber and a straight channel connecting said chambers, said walls forming a gas tight enclosure and the walls defining said first chamber and said channel being electrically conductive; an exhaust outlet in said first chamber for exhausting gas therefrom to establish and maintain a low gas pressure inside said enclosure, said low gas pressure being within a range suitable for establishing and maintaining a cold cathode gas discharge within said enclosure; a non-heated cathode disposed within said second chamber opposite said channel; means for electrically connecting between said non-heated cathode and said walls defining said channel a source of sufficiently high voltage to establish and maintain a cold cathod gas discharge between said non-heated cathode and said channel, thereby causing an electron stream to travel through said channel into said first chamber; and means for supporting a material within said first chamber in the path of said electron stream, the surface of a material supported thereby and exposed to said electron stream being caused to X-ray fluoresce.
Claim 2
Dependent Claim
186 words
Apparatus for causing X-ray fluorescence of the surface of a material, comprising: walls defining a first chamber, a second chamber and a straight channel connecting said chambers, said walls forming a gas tight enclosure and the walls defining said first chamber and said channel being electrically conductive; an exhaust outlet in said first chamber for exhausting gas therefrom to establish and maintain a low gas pressure inside said enclosure, said low gas pressure being within a range suitable for establishing and maintaining a cold cathode gas discharge within said enclosure; a non-heated cathode disposed within said second chamber opposite said channel; means for electrically connecting between said non-heated cathode and said walls defining said channel a source of sufficiently high voltage to establish and maintain a cold cathod gas discharge between said non-heated cathode and said channel, thereby causing an electron stream to travel through said channel into said first chamber; and means for supporting a material within said first chamber in the path of said electron stream, the surface of a material supported thereby and exposed to said electron stream being caused to X-ray fluoresce.
Claim 3
Dependent Claim
63 words
Apparatus as defined in claim 1 further characterized by a grid structure substantially surrounding said non-heated cathode, said grid structure having an aperture positioned directly between said cathode and channel to allow a gas discharge therethrough, said grid structure being electrically connected to said non-heated cathode through a parallel combination of resistance and capacitance, said grid structure acting to stabilize the gas discharge.
Claim 4
Dependent Claim
29 words
Apparatus as defined in claim 1 wherein the walls of said channel are maintained at an electrical potential between 15 and 30 thousand volts more positive than said cathode.
Claim 5
Dependent Claim
40 words
Apparatus as defined in claim 1 whereiN the walls defining said first chamber are in electrical contact with the walls defining said channel and the walls defining said second chamber at least in the vacinity of said channel are insulative.
Claim 6
Dependent Claim
26 words
Apparatus as defined in claim 1 wherein said low gas pressure maintained within said enclosure is on the order of 10 2 or 10 1 Torr.
Claim 7
Dependent Claim
25 words
Apparatus as defined in claim 1 wherein the residual gas remaining in said enclosure at said low gas pressure is substantially air or substantially nitrogen.
Claim 8
Dependent Claim
42 words
Apparatus as defined in claim 1 further characterized by a gas inlet in said first or second chamber for leaking gas into said first or second chamber to continuously flush from said enclosure gases released from the material supported for X-ray fluorescence.
Claim 9
Dependent Claim
22 words
Apparatus as defined in claim 7 wherein the gas leaking into said enclosure through said inlet is substantially air or substantially nitrogen.
References Cited (Backward Citations)
US2924715A
Cited
US3155827A
Cited
US3346736A
Cited
US3307066A
Cited
US3435211A
Cited
US3374349A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |