Gyrotron traveling-wave device including quarter wavelength anti-reflective dielectric layer to enhance microwave absorption

Claim 2

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; and an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surfaces of said plurality of suppression rings, said anti-reflective layer being formed of a dielectric material having a dielectric constant determined according to the equation: ##EQU3## where ε layer is the dielectric constant of said coating layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said suppressor rings.

Claim 3

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; and an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surface of said plurality of suppression rings, said anti-reflective layer, being formed of a dielectric material having a dielectric constant determined according to the equation: ##EQU4## where ε layer is the dielectric constant of said coating layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said suppressor rings; and a plurality of parallel highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings.

Claim 4

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; and an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surface of said plurality of suppression rings, said anti-reflective layer, being formed of a dielectric material having a dielectric constant determined according to the equation: ##EQU4## where ε layer is the dielectric constant of said coating layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said suppressor rings; and a plurality of parallel highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings.

Claim 5

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; and an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surfaces of said plurality of suppression rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of anti-reflective layer, and m is a positive odd integer.

Claim 6

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; and an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surfaces of said plurality of suppression rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of anti-reflective layer, and m is a positive odd integer.

Claim 7

A drift tube a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surfaces of said plurality of suppression rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of anti-reflective layer, and m is a positive odd integer; and a plurality of parallel highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings.

Claim 8

A drift tube a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said suppressor rings to said medium and for reducing reflections of incident radiation from the surfaces of said suppressor rings located on the surfaces of said plurality of suppression rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of anti-reflective layer, and m is a positive odd integer; and a plurality of parallel highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings.

Claim 9

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface fo said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings; said anti-reflective layer having a dielectric constant determined according to the equation: ##EQU5## where ε layer is the dielectric constant of said anti-reflective layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said suppressor rings.

Claim 10

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising: a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface fo said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings; said anti-reflective layer having a dielectric constant determined according to the equation: ##EQU5## where ε layer is the dielectric constant of said anti-reflective layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said suppressor rings.

Claim 11

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising; a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of said anti-reflective layer, and m is a positive odd integer.

Claim 12

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising; a hollow waveguide positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings, said anti-reflective layer having a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said waveguide, n is the index of refraction of said anti-reflective layer, and m is a positive odd integer.

Claim 13

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising: a hollow wavegude positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings; and wherein: said suppressor rings are formed of Ceralloy™; said conductive rings are formed of copper; and said anti-reflective layer is formed of Macor™.

Claim 14

A drift tube for use between an electron gun and a cavity in a gyrotron traveling-wave device, comprising: a hollow wavegude positioned to surround an electron beam passing from said electron gun to said cavity, said waveguide enclosing a medium through which said electron beam travels; a plurality of parallel highly lossy dielectric suppressor rings surrounding said electron beam and located adjacent to the inner surface of said waveguide, said suppressor rings acting to absorb parasitic radiation produced by said electron beam; a plurality of highly conductive rings surrounding said electron beam and located in contact with the inner surface of said waveguide, said plurality of conductive rings being interspaced with said plurality of suppressor rings, said conductive rings acting to remove static charges from said plurality of suppressor rings; an anti-reflective dielectric layer located on the surfaces of said plurality of suppressor rings, said anti-reflective layer matching the impedance of said suppressor rings to said medium, said anti-reflective layer reducing reflections of incident radiation from the surface of said suppressor rings; and wherein: said suppressor rings are formed of Ceralloy™; said conductive rings are formed of copper; and said anti-reflective layer is formed of Macor™.

Claim 15

A cavity for use in a gyrotron traveling-wave device, comprising: a hollow tuned cavity structure including an input port and an output port, said cavity structure being positioned to receive an electron beam through its input port; at least one highly lossy dielectric suppressor ring surrounding said electron beam and located adjacent to the inner surface of said cavity structure in the vicinity of said output port, said at least one suppressor ring acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said at least one suppressor ring to a medium located within said cavity structure and for reducing reflections of incident radiation from the surfaces of said at least one suppressor ring, said anti-reflective layer located on the surface of said at least one suppressor ring, said anti-reflective layer being formed of a dielectric material, and said anti-reflective layer has a dielectric constant determined according to the equation: ##EQU6## where ε layer is the dielectric constant of said anti-reflective layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said at least one suppressor ring.

Claim 16

A cavity for use in a gyrotron traveling-wave device, comprising: a hollow tuned cavity structure including an input port and an output port, said cavity structure being positioned to receive an electron beam through its input port; at least one highly lossy dielectric suppressor ring surrounding said electron beam and located adjacent to the inner surface of said cavity structure in the vicinity of said output port, said at least one suppressor ring acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said at least one suppressor ring to a medium located within said cavity structure and for reducing reflections of incident radiation from the surfaces of said at least one suppressor ring, said anti-reflective layer located on the surface of said at least one suppressor ring, said anti-reflective layer being formed of a dielectric material, and said anti-reflective layer has a dielectric constant determined according to the equation: ##EQU6## where ε layer is the dielectric constant of said anti-reflective layer, ε medium is the dielectric constant of said medium, and ε substrate is the dielectric constant of said at least one suppressor ring.

Claim 17

A cavity for use in a gyrotron traveling-wave device, comprising: a hollow tuned cavity structure including an input port and an output port, said cavity structure being positioned to receive an electron beam through its input port; at least one highly lossy dielectric suppressor ring surrounding said electron beam and located adjacent to the inner surface of said cavity structure in the vicinity of said output port, said at least one suppressor ring acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said at least one suppressor ring to a medium located within said cavity structure and for reducing reflections of incident radiation from the surfaces of said at least one suppressor ring, said anti-reflective layer located on the surface of said at least one suppressor ring, said anti-reflective layer being formed of a dielectric material, and said anti-reflective layer has a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said cavity structure, n is the index of refraction of said anti-reflective layer, and m is a positive odd integer.

Claim 18

A cavity for use in a gyrotron traveling-wave device, comprising: a hollow tuned cavity structure including an input port and an output port, said cavity structure being positioned to receive an electron beam through its input port; at least one highly lossy dielectric suppressor ring surrounding said electron beam and located adjacent to the inner surface of said cavity structure in the vicinity of said output port, said at least one suppressor ring acting to absorb parasitic radiation produced by said electron beam; an anti-reflective layer for matching the impedance of said at least one suppressor ring to a medium located within said cavity structure and for reducing reflections of incident radiation from the surfaces of said at least one suppressor ring, said anti-reflective layer located on the surface of said at least one suppressor ring, said anti-reflective layer being formed of a dielectric material, and said anti-reflective layer has a thickness determined according to the equation: d=mλg/4n where d is the thickness of said anti-reflective layer, λ g is the waveguide wavelength of said cavity structure, n is the index of refraction of said anti-reflective layer, and m is a positive odd integer.