US3644731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for producing an ion beam by removing electrons from a plasma
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1969-04-29
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Granted: 1972-02-22
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Expires: 1989-04-29
Abstract
Abstract The present invention relates to a method of production of ions wherein a plasma is generated from a target and then subjected to a number of successive electric fields to sort the particles which form the plasma by providing the successive electric fields with increasing amplitudes to slow down the electrons, collecting said electrons on electrodes and then causing the ion-enriched beam to converge towards the exit aperture by means of a final electric field.
Inventors
- 👤 Jean-Francois Eloy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:57
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/16; H01J49/161
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
240 words
Device for generating an ion beam, comprising, in an evacuated enclosure: a target for emission of a plasma of ions and electrons and carried in a tubular member to provide an equipotential cage for said target, an extraction plate formed with a circular opening aligned with said tubular member and in spaced relation thereto, an electrically conductive grid disposed transversely of said opening and carried by said extraction plate, a preacceleration plate in spaced relation with said extraction plate and formed with a wide slot aligned with said opening, an electrically conductive grid disposed transversely of said slot and carried by said preacceleration plate, an annular concentration electrode aligned with said preacceleration plate and in spaced relation thereto, an acceleration and beam definition plate located in spaced relation to said electrode and formed with a slit narrower than said slot and aligned therewith, electrical voltage means connected to said target, to said plates and to said electrode for bringing said preacceleration plate, said extraction plate and target to increasing positive potentials, respectively, with respect to said acceleration plate and bringing said concentration electrode to a potential slightly higher than that of the preacceleration plate, whereby electrons will be removed from said plasma by said extraction and preacceleration plates and the resulting ion beam will be focused by said concentration electrode at said slit in said acceleration and beam definition plate, and means for exciting said target to produce the plasma.
Claim 2
Dependent Claim
240 words
Device for generating an ion beam, comprising, in an evacuated enclosure: a target for emission of a plasma of ions and electrons and carried in a tubular member to provide an equipotential cage for said target, an extraction plate formed with a circular opening aligned with said tubular member and in spaced relation thereto, an electrically conductive grid disposed transversely of said opening and carried by said extraction plate, a preacceleration plate in spaced relation with said extraction plate and formed with a wide slot aligned with said opening, an electrically conductive grid disposed transversely of said slot and carried by said preacceleration plate, an annular concentration electrode aligned with said preacceleration plate and in spaced relation thereto, an acceleration and beam definition plate located in spaced relation to said electrode and formed with a slit narrower than said slot and aligned therewith, electrical voltage means connected to said target, to said plates and to said electrode for bringing said preacceleration plate, said extraction plate and target to increasing positive potentials, respectively, with respect to said acceleration plate and bringing said concentration electrode to a potential slightly higher than that of the preacceleration plate, whereby electrons will be removed from said plasma by said extraction and preacceleration plates and the resulting ion beam will be focused by said concentration electrode at said slit in said acceleration and beam definition plate, and means for exciting said target to produce the plasma.
Claim 3
Dependent Claim
52 words
A device as described in claim 1, the potential of said target, of said extraction plate, of said preacceleration plate, and of said concentration electrode with respect to said acceleration plate being respectively about 8.5 kv., from 8.5 to 8.3 kv., from 8.3 to 7.5 kv. and from 8.5 to 7.5 kv.
Claim 4
Dependent Claim
17 words
An ion source in accordance with claim 1, said tubular member having an internal rectangular cross section.
Claim 5
Dependent Claim
16 words
An ion source in accordance with claim 1, said tubular member having a circular cross section.
Claim 6
Dependent Claim
21 words
An ion source in accordance with claim 1, including a window in said tubular member and a grid in said window.
Claim 7
Dependent Claim
15 words
An ion source in accordance with claim 1, including a diaphragm in said extraction plate.
Claim 8
Dependent Claim
30 words
An ion source in accordance with claim 1, said means for exciting said target including a laser and means for directing the beam produced by said laser into said target.
Claim 9
Dependent Claim
41 words
An ion source in accordance with claim 7, said means for directing the laser beam onto said target includes a port in said enclosure, a lens secured in said port and a plane mirror reflecting the laser beam onto said target.
Claim 10
Dependent Claim
53 words
A mass spectrograph including the ion source of claim 1, wherein said exciting means comprises a laser, a vacuum pumping system connected to the enclosure of said source, means for the magnetic deflection of the ion beam derived from said source and means for recording the deflected ion beam on a photographic plate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |