Patent US3872349A successfully refreshed from Google Patents.
US3872349A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for generating radiation
Assignee: Fusion Systems Corp
•
Filing: 1973-08-22
•
Granted: 1975-03-18
•
Expires: 1993-08-22
Abstract
Abstract An improved structure for a microwave generated plasma light source for emitting radiation in the ultraviolet and visible portions of the spectrum. Microwave energy generated by a microwave source is coupled to a plasma forming medium which is confined in a longitudinally extending tube. The tube is surrounded along its length by a microwave chamber, a portion of which comprises a means for reflecting the emitted radiation and a portion of which comprises a mesh-like member which is substantially transparent to the emitted radiation, but which is relatively opaque to the microwave energy. The microwave energy may be fed to the microwave chamber either from the end thereof, or from the top or sides if the microwave sources is housed in a waveguide located on the top or sides of the chamber. The plasma forming medium is confined at a relatively high pressure and the microwave energy is coupled thereto at a high enough power density to create electron densities in the plasma in excess of the cutoff density. Electrons are excited by the transformation of waves and wave absorption and collide with the heavy particles of the plasma which emit ultraviolet and visible radiation upon de-excitation.
Inventors
- 👤 Donald M Spero
- 👤 Bernard J Eastlund
- 👤 Michael G Ury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:12
CPC Classifications
H; H01; H01J; H01J65/00; H01J65/04; H01J65/042; H01J65/044; Y; Y10; Y10S; Y10S422/00; Y10S422/906
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
169 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending nonresonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending elliptically shaped reflecting member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending plane member joined to said elliptically shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said elliptical reflecting member through said transparent member and out of said chamber.
Claim 2
Dependent Claim
169 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending nonresonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending elliptically shaped reflecting member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending plane member joined to said elliptically shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said elliptical reflecting member through said transparent member and out of said chamber.
Claim 3
Dependent Claim
21 words
The light source of claim 1 wherein said longitudinally extending envelope is located approximately along the focus of said elliptical reflector.
Claim 4
Dependent Claim
216 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending nonresonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending shaped reflecting member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending member joined to said shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said reflecting member through said transparent member and out of said chamber, said means for coupling comprising at least a microwave guiding enclosure in which said microwave energy generating means is located, one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling microwave energy to the interior of said chamber.
Claim 5
Dependent Claim
216 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending nonresonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending shaped reflecting member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending member joined to said shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said reflecting member through said transparent member and out of said chamber, said means for coupling comprising at least a microwave guiding enclosure in which said microwave energy generating means is located, one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling microwave energy to the interior of said chamber.
Claim 6
Dependent Claim
21 words
The light source of claim 3 wherein said enclosure comprises a waveguide and said portion comprises one side of said waveguide.
Claim 7
Dependent Claim
47 words
The light source of claim 4 wherein said microwave chamber is secured to an annular flange at each longitudinal end thereof to form an enclosure which prevents the escape of microwaves, and at least a pair of support bars are connected between said flanges for structural rigidity.
Claim 8
Dependent Claim
50 words
The light source of claim 5 wherein holding brackets for supporting said longitudinally extending envelope are secured in holes in said flanges, said envelope being formed with mounting extensions at each end thereof which extend parallel to said axis of said envelope and which are supported by said holding brackets.
Claim 9
Dependent Claim
32 words
The light source of claim 4 wherein said energy generating means is located near one end of said waveguide and said at least a slot antenna is located near said other end.
Claim 10
Dependent Claim
17 words
The light source of claim 7 wherein said at least a slot antenna comprises two slot antennae.
Claim 11
Dependent Claim
27 words
The light source of claim 7 wherein said waveguide is situated so that the long dimension thereof is parallel to the longitudinal direction of said reflecting member.
Claim 12
Dependent Claim
39 words
The light source of claim 9 wherein three sides of said waveguide are comprised of three longitudinally extending members at right angles to each other, and the fourth side is comprised of said curved portion of said reflecting member.
Claim 13
Dependent Claim
67 words
The light source of claim 10 wherein said at least a waveguide comprises two of said waveguides which are situated parallel to each other at different portions across the periphery of said reflecting member, the microwave energy generating means in one of said waveguides being located near the opposite end from the end that the microwave energy generating means in the other of said waveguides is located.
Claim 14
Dependent Claim
27 words
The light source of claim 7 wherein said waveguide is situated so that the long dimension thereof is perpendicular to the longitudinal direction of said reflecting member.
Claim 15
Dependent Claim
21 words
The light source of claim 12 wherein the cross-section of said waveguide is concentric with said portion of said reflecting member.
Claim 16
Dependent Claim
211 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending non-resonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending shaped reflecting member which is opaque to micRowaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending member joined to said shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said reflecting member through said transparent member and out of said chamber, said means for coupling comprising a rectangular to circular waveguide transition section, the output of said generating means being coupled to the rectangular portion of the section and the circular portion being connected to an end of said microwave chamber for coupling energy into said chamber.
Claim 17
Dependent Claim
211 words
A microwave generated plasma light source for emitting a longitudinally extending sheet of light of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending non-resonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending shaped reflecting member which is opaque to micRowaves but is light reflective on its inside surface for reflecting light emitted by said envelope and a second longitudinally extending member joined to said shaped reflecting member along the bottom of said reflecting member to form said chamber, said second member being substantially opaque to microwaves but substantially transparent to said emitted light, whereby light emitted along the entire length of said envelope is reflected as a sheet of light by said reflecting member through said transparent member and out of said chamber, said means for coupling comprising a rectangular to circular waveguide transition section, the output of said generating means being coupled to the rectangular portion of the section and the circular portion being connected to an end of said microwave chamber for coupling energy into said chamber.
Claim 18
Dependent Claim
22 words
The light source of claim 4 wherein said reflecting member is elliptically shaped and said second member is a plane mesh-like member.
Claim 19
Dependent Claim
29 words
The light source of claim 4 wherein said reflecting member is parabolically shaped, the cross-section of said envelope is semi-circular and said second member is a plane mesh-like member.
Claim 20
Dependent Claim
34 words
The light source of claim 4 wherein said reflecting member is semi-circular in shape, said second member is a mesh-like member which is semi-circular in shape and the cross-section of said envelope is circular.
Claim 21
Dependent Claim
153 words
A microwave generated plasma light source of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending non-resonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending cylindrical member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope having an annular cross-section whereby emitted light is reflected into the annulus of said envelope, said means for coupling comprising at least a microwave guiding enclosure in which said microwave energy generating means located one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling microwave energy to the interior of said chamber.
Claim 22
Dependent Claim
153 words
A microwave generated plasma light source of arbitrary length comprising means for generating microwave energy, means for coupling said generated microwave energy to a discharge unit, said discharge unit comprising a longitudinally extending non-resonant microwave chamber of an arbitrary length which encloses a sealed plasma-forming medium containing envelope which extends in said longitudinal direction in said chamber, said chamber being comprised of a first longitudinally extending cylindrical member which is opaque to microwaves but is light reflective on its inside surface for reflecting light emitted by said envelope having an annular cross-section whereby emitted light is reflected into the annulus of said envelope, said means for coupling comprising at least a microwave guiding enclosure in which said microwave energy generating means located one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling microwave energy to the interior of said chamber.
Claim 23
Dependent Claim
186 words
A microwave generated plasma light source of arbitrary length comprising means for generating microwave energy, means for coupling and generated energy to a discharge unit, said discharge unit comprising a microwave chamber which encloses a sealed plasma forming medium-containing envelope, said chamber being comprised of a first reflecting member having the shape of a parabolic surface of revolution, and a second plane mesh-like member which contacts said first member, said first member being opaque to microwaves but being reflective on its inside surface for reflecting said emitted light and said mesh-like member being substantially opaque to microwaves but substantially transparent to said emitted light, said sealed container being located at or near the focus of said parabolic surface and the longitudinal axis of said sealed envelope being parallel to the axis of revolution of said parabolic reflector, said means for coupling comprising at least a microwave guiding enclosure in which said energy generating means is located, one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling energy to the interior of said chamber.
Claim 24
Dependent Claim
186 words
A microwave generated plasma light source of arbitrary length comprising means for generating microwave energy, means for coupling and generated energy to a discharge unit, said discharge unit comprising a microwave chamber which encloses a sealed plasma forming medium-containing envelope, said chamber being comprised of a first reflecting member having the shape of a parabolic surface of revolution, and a second plane mesh-like member which contacts said first member, said first member being opaque to microwaves but being reflective on its inside surface for reflecting said emitted light and said mesh-like member being substantially opaque to microwaves but substantially transparent to said emitted light, said sealed container being located at or near the focus of said parabolic surface and the longitudinal axis of said sealed envelope being parallel to the axis of revolution of said parabolic reflector, said means for coupling comprising at least a microwave guiding enclosure in which said energy generating means is located, one wall of said enclosure comprising a portion of said reflecting member, said portion having at least a slot antenna therein for coupling energy to the interior of said chamber.
Claim 25
Dependent Claim
20 words
The light source of claim 4 wherein said reflecting member has a cooling slot therein running longitudinally along said member.
Claim 26
Dependent Claim
48 words
The light source of claim 4 wherein said envelope has mounting extensions formed thereon oriented in a direction perpendicular to said longitudinal direction, said reflecting member having mounting holes therein and said exTensions being secured in said holes to effect the mounting of said envelope in said chamber.
Claim 27
Dependent Claim
77 words
The light source of claim 4 wherein said reflecting member is a curved reflecting member and said second member is made of mesh-like material which is substantially opaque to microwaves and substantially transparent to said emitted radiation, said chamber further being sealed at each end thereof by a member of said mesh-like material, whereby the bottom and ends of said chamber are microwave opaque and emitted light transparent to facilitate end by end placement of said sources.
Claim 28
Dependent Claim
48 words
A plurality of light sources as recited in claim 22 placed with the mesh-like material at the right longitudinal end of one light source flat against the mesh-like material at the left longitudinal end of the adjacent light source to form a continuous straight row of light sources.
Claim 29
Dependent Claim
49 words
A plurality of light sources as recited in claim 23 wherein the mesh-like material at each longitudinal end forms a plane member and wherein said plane members of each light source are at an angle of other than 90* with respect to the longitudinal axis of the light sources.
Claim 30
Dependent Claim
155 words
A high efficiency high power microwave generated plasma light source for emitting radiation in the ultraviolet range comprising a plasma-forming medium confined in a longitudinally extending cylindrical container having a diameter much greater than twice the classical skin depth at a pressure of from 1 mm Hg to 2 atm., microwave energy source means for generating energy in the microwave range, means for coupling said microwave energy to said medium in said container so that the power density existing in said medium is at least 50 watts/cm3 whereby electrons having densities far in excess of the cut-off density are created in said medium and anomalous absorption of said energy occurs at skin depths greater than C/ omega p where C is the speed of light and omega p is the plasma frequency, which electrons collide with heavy particles of said medium to cause said heavy particles to become collisionally excited and to emit said radiation.
Claim 31
Dependent Claim
155 words
A high efficiency high power microwave generated plasma light source for emitting radiation in the ultraviolet range comprising a plasma-forming medium confined in a longitudinally extending cylindrical container having a diameter much greater than twice the classical skin depth at a pressure of from 1 mm Hg to 2 atm., microwave energy source means for generating energy in the microwave range, means for coupling said microwave energy to said medium in said container so that the power density existing in said medium is at least 50 watts/cm3 whereby electrons having densities far in excess of the cut-off density are created in said medium and anomalous absorption of said energy occurs at skin depths greater than C/ omega p where C is the speed of light and omega p is the plasma frequency, which electrons collide with heavy particles of said medium to cause said heavy particles to become collisionally excited and to emit said radiation.
References Cited (Backward Citations)
US3313979A
Cited
US3431461A
Cited
US3280364A
Cited
US3378723A
Cited
US3374393A
Cited
US3434071A
Cited
US3541372A
Cited
US3648100A
Cited
US3641389A
Cited
US3609448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |