US4392080A
Expired / Lapsed
US
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Means and method for the focusing and acceleration of parallel beams of charged particles
Assignee: United States Department of Energy
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Filing: 1980-05-23
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Granted: 1983-07-05
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Expires: 2000-05-23
Abstract
Abstract A novel apparatus and method for focussing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The quadrupole arrays may comprise electrodes which are shared by two or more quadrupoles. Such quadrupole arrays are particularly adapted to providing strong focussing forces for high current, high brightness, beams of charged particles, said beams further comprising a plurality of parallel beams, or beamlets, each such beamlet being focussed by one quadrupole of the array. Such arrays may be incorporated in various devices wherein beams of charged particles are accelerated or transported, such as linear accelerators, klystron tubes, beam transport lines, etc.
Inventors
- 👤 Alfred W. Maschke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:11
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/02; H01J23/08; H05; H05H; H05H9/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
34 words
A planar array of electrostatic quadrupoles including a plurality of electrodes suitable for applying strong focusing forces to a plurality of transversely spaced parallel beams of charged particles, said array forming a unitary structure.
Claim 2
Dependent Claim
34 words
A planar array of electrostatic quadrupoles including a plurality of electrodes suitable for applying strong focusing forces to a plurality of transversely spaced parallel beams of charged particles, said array forming a unitary structure.
Claim 3
Dependent Claim
26 words
The array of claim 1 wherein at least one of the electrodes of at least one of said quadrupoles is shared by two of said quadrupoles.
Claim 4
Dependent Claim
40 words
The array of claim 2, wherein said electrodes are substantially cylindrical in shape and have a diameter approximately equal to the diameter of an aperture of said quadrupoles, the axes of said cylinders being arranged essentially parallel to the beams.
Claim 5
Dependent Claim
45 words
The array of claim 2 wherein said electrodes have a length along an axis parallel to said beams proportional to the velocity of the particles and inversely proportional to the magnitude of the focusing forces, so as to maintain uniform focusing with increasing particle velocity.
Claim 6
Dependent Claim
85 words
A drift tube assembly comprising: (a) an array as claimed in claims 1, 2, 3, or 4, and (b) means for shielding said array from RF accelerating fields, said means having a plurality of apertures to allow the passage of a plurality of parallel beams of charged particles, said apertures being aligned with the apertures of the quadrupoles of said array whereby particles may be shielded from such RF field and subject to strong focusing by said quadrupoles as they pass through said drift tube.
Claim 7
Dependent Claim
55 words
An accelerating assembly comprising: (a) a linear uniformly separated series of axially spaced drift tube assemblies as described in claim 5, the quadrupole arrays of adjacent drift tube assemblies having reversed DC potentials with respect to each other; and (b) means for generating an RF accelerating field in the gaps between said drift tube assemblies.
Claim 8
Dependent Claim
62 words
An accelerating assembly as described in claim 6 wherein there is a 180 degree difference in the phase of said RF fields at successive gaps, and the length of said drift tube assemblies is such that the distance measured from the center of one gap to the center of the next is essentially equal an odd number of half particle wave lengths.
Claim 9
Dependent Claim
51 words
An accelerating assembly as claimed in claim 7, wherein the length of the electrodes measured in particle wave lengths, of said arrays of said drift tube assemblies is equal to a fraction ranging about from 0.2 to 0.4 multiplied by the length of said drift tube assembly plus one gap width.
Claim 10
Dependent Claim
95 words
A Linac, comprising: (a) an ion source; (b) an accelerating assembly as described in claim 8; (c) a low energy beam transport means for adapting the emittance of said source to the acceptance of said assembly, said transport means being positioned between said ion source and said accelerating assembly, (d) first power supply means for supply RF power to said accelerating assembly; (e) second power supply means for supply DC to the electrodes of said quadrupoles; and (f) vacuum means for maintaining said ion source, accelerating assembly and low energy beam tansport in a vacuum.
Claim 11
Dependent Claim
78 words
The Linac of claim 9 wherein said low energy beam transport means comprises a linear array of electrostatic quadrupoles, said quadrupoles being equal in length, aligned with said accelerating assembly and being separated from each other by a conductive plate having a plurality of apertures aligned with the apertures of said quadrupoles whereby said beams are provided with a preliminary focusing so as to adapt the emittance of said ion source to the acceptance of said accelerating array.
Claim 12
Dependent Claim
25 words
The Linac of claim 10 wherein said low energy beam transport quadrupoles are operated at a lower voltage than said quadrupoles of said accelerating assembly.
Claim 13
Dependent Claim
39 words
The Linac of claim 11 wherein a buncher means for pre-bunching the ions from said ion source into bunches suitable for acceleration by said accelerating assembly is positioned between said ion source and said low energy beam transport means.
Claim 14
Dependent Claim
64 words
The Linac of claim 12 wherein said buncher means comprises a conductive plate approximately one-half particle wave length in thickness and having a plurality of apertures aligned with the apertures of said quadrupoles, said plate being connected to a source of RF power equal in frequency to the frequency of the accelerating RF and having predetermined voltage and phase relation to said accelerating RF.
Claim 15
Dependent Claim
74 words
A Linac wherein the improvement comprises providing within each drift tube assembly means for generating field configurations suitable for applying strong focusing forces to a plurality of transversely spaced parallel beams of charged particles in one direction orthogonal to said beams and strong defocusing forces in the other orthogonal direction, said focusing and defocusing forces being reversed, in adjacent drift tube assemblies, whereby a plurality of parallel accelerating channels is formed within said Linac.
Claim 16
Dependent Claim
74 words
A Linac wherein the improvement comprises providing within each drift tube assembly means for generating field configurations suitable for applying strong focusing forces to a plurality of transversely spaced parallel beams of charged particles in one direction orthogonal to said beams and strong defocusing forces in the other orthogonal direction, said focusing and defocusing forces being reversed, in adjacent drift tube assemblies, whereby a plurality of parallel accelerating channels is formed within said Linac.
Claim 17
Dependent Claim
17 words
The Linac of claim 14 wherein said field configurations are provided by planar arrays of electrostatic quadrupoles.
Claim 18
Dependent Claim
17 words
The Linac of claim 15 wherein said arrays comprise an electrode shared by two of said quadrupoles.
Claim 19
Dependent Claim
54 words
The Linac of claims 14, 15, or 16 wherein the average accelerating field between drift tubes is equal to 0.2 times the equivalent maximum focussing field within said drift tubes and the normalized longitudinal acceptance and normalized transverse acceptance of said Linac are approximately equal, whereby the maximum brightness of said Linac is optimized.
Claim 20
Dependent Claim
56 words
Means for focusing and maintaining beams of charged particles in spaced apart parallel relationship to each other comprising an array of transversely spaced positive and negative electrodes forming a different electrostatic quadrupole for each beam wherein each of said quadrupoles includes an electrode which forms a part of another one of said quadrupoles in the array.
Claim 21
Dependent Claim
56 words
Means for focusing and maintaining beams of charged particles in spaced apart parallel relationship to each other comprising an array of transversely spaced positive and negative electrodes forming a different electrostatic quadrupole for each beam wherein each of said quadrupoles includes an electrode which forms a part of another one of said quadrupoles in the array.
Claim 22
Dependent Claim
104 words
A charged particle process comprising the steps of: (a) generating a plurality of spaced apart parallel beams of charged particles; (b) providing a focusing array of electrostatic fields transverse to the axes of said beams for applying strong focusing forces to the beams in one direction and strong defocusing forces to the beams in the orthogonal direction; (c) providing a second focusing array of electrostatic fields next adjacent to the first fields along the axes of said beams and orthogonal to the first fields for applying strong focusing and defocusing forces to the beams at right angles to the forces of the first array.
Claim 23
Dependent Claim
104 words
A charged particle process comprising the steps of: (a) generating a plurality of spaced apart parallel beams of charged particles; (b) providing a focusing array of electrostatic fields transverse to the axes of said beams for applying strong focusing forces to the beams in one direction and strong defocusing forces to the beams in the orthogonal direction; (c) providing a second focusing array of electrostatic fields next adjacent to the first fields along the axes of said beams and orthogonal to the first fields for applying strong focusing and defocusing forces to the beams at right angles to the forces of the first array.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |