US3732488A — Electron spin inductors at microwaves

Claim 1

Independent Claim 277 words

In a spin induction spectrometer for magnetic resonance measurements on a spin sample: a. means defining a bimodal resonant composite microwave structure including therein at least one intrinsically bimodal cavity of square cross-section; b. said intrinsic bimodal cavity having aperture means permitting a spin sample to be introduced therein; c. an external source of microwave energy and an external microwave detecting device; d. said intrinsic bimodal cavity supporting two modes degenerate in frequency, the first of said modes being excited by the external microwave energy and used for stimulating the spins and the second of said modes excited by the microwave energy irradiated by the stimulated spins at resonance, said first mode being polarized and orthogonal to said second mode, said second mode also being polarized and decoupled from said first mode; e. said microwave structure having further aperture means acting as a polarized coupling device such that said external source of microwave energy is coupled only to said first mode, and additional aperture means acting as a second polarized coupling device coupling the second mode to said external microwave detecting device, said further and additional aperture means having respective polarization planes orthogonal and thereby being decoupled from each other; f. said intrinsic bimodal cavity supporting the oscillation of any integral number of half wavelengths in each of the two modes, the two said modes forming pairs of decoupled degenerate orthogonal modes; g. said intrinsic bimodal cavity being oriented in an external static magnetic field such that throughout the volume occupied by the spin sample the direction of said static magnetic field is perpendicular to the two orthogonal microwave magnetic field vectors of the said two modes.

Claim 2

Dependent Claim 277 words

In a spin induction spectrometer for magnetic resonance measurements on a spin sample: a. means defining a bimodal resonant composite microwave structure including therein at least one intrinsically bimodal cavity of square cross-section; b. said intrinsic bimodal cavity having aperture means permitting a spin sample to be introduced therein; c. an external source of microwave energy and an external microwave detecting device; d. said intrinsic bimodal cavity supporting two modes degenerate in frequency, the first of said modes being excited by the external microwave energy and used for stimulating the spins and the second of said modes excited by the microwave energy irradiated by the stimulated spins at resonance, said first mode being polarized and orthogonal to said second mode, said second mode also being polarized and decoupled from said first mode; e. said microwave structure having further aperture means acting as a polarized coupling device such that said external source of microwave energy is coupled only to said first mode, and additional aperture means acting as a second polarized coupling device coupling the second mode to said external microwave detecting device, said further and additional aperture means having respective polarization planes orthogonal and thereby being decoupled from each other; f. said intrinsic bimodal cavity supporting the oscillation of any integral number of half wavelengths in each of the two modes, the two said modes forming pairs of decoupled degenerate orthogonal modes; g. said intrinsic bimodal cavity being oriented in an external static magnetic field such that throughout the volume occupied by the spin sample the direction of said static magnetic field is perpendicular to the two orthogonal microwave magnetic field vectors of the said two modes.

Claim 3

Dependent Claim 216 words

A microwave composite structure as recited in claim 1 wherein said structure; a. comprises one unimodal section supporting only said first resonant mode and said intrinsic bimodal cavity of square cross-section supporting said first and second modes, said unimodal section being coupled to said intrinsic bimodal cavity through a common opening therebetween, said unimodal section forming a common composite resonant cavity for said first mode with said intrinsic bimodal cavity; b. said unimodal section forming said first polarized coupling device for said first mode of said intrinsic bimodal cavity; c. said unimodal section including aperture means coupling the external source of microwave energy to said first mode, the microwave energy propagating from said unimodal section to said intrinsic bimodal cavity; d. said structure including means for adjusting the microwave polarization plane of said unimodal section with respect to the polarization plane of the second mode of said intrinsic bimodal cavity, said means for adjusting being disposed between said unimodal section and said intrinsic bimodal cavity for decreasing the coupling between said two modes, said means for adjusting comprising means for mutually rotating the two respective microwave supportive structures about a binary symmetry axis of the cavity parallel to the intersection of the polarization planes of said first and second orthogonal modes of said intrinsic bimodal cavity.

Claim 4

Dependent Claim 197 words

A microwave composite structure as recited in claim 1 wherein said structure: a. comprises a unimodal section supporting only one resonant mode and said intrinsic bimodal cavity of square cross-section supporting said first and second modes, said unimodal section being coupled to said intrinsic bimodal section through an opening therebetween, said unimodal section forming a common composite resonant cavity for said second mode with said intrinsic bimodal section; b. said unimodal section forming said polarized coupling device relative to said second mode of then intrinsic bimodal cavity; c. said unimodal section including aperture means for coupling only said second mode whose microwave energy comes from the stimulated spins to an external microwave detector; d. said structure including means disposed between said unimodal section and said intrinsic bimodal cavity for decreasing the coupling between said first and second modes, said means disposed between adjusting the microwave polarization plane of said unimodal section with respect to the polarization plane of the first mode of said intrinsic bimodal cavity through a mutual rotation of both said sections about an axis defined by the intersection of the polarization planes of said first and second orthogonal modes of said intrinsic bimodal cavity.

Claim 5

Dependent Claim 147 words

A microwave composite structure as recited in claim 1, wherein said additional aperture means acting as said second polarized coupling device includes a pair of elongated slots in the walls of said intrinsic bimodal cavity, said slots being elongated in a direction parallel to the magnetic lines of said second mode, signal combining means having three ports with two of said ports being connected to respective ones of said pair of slots for producing a combined output at the third port corresponding to a vector sum of the spin resonance signals extracted via said pair of slots from said second mode, said slots being placed in selected positions of selected cavity walls such that the directions of the vectors of the microwave magnetic fields of the first and second mode at their positions have the same and opposite symmetry characteristics, respectively, with respect to the third port.

Claim 6

Dependent Claim 151 words

A microwave composite structure as recited in claim 2, wherein said structure comprises: a. a plurality of intrinsic bimodal cavities each capable of supporting said first and second modes, and a single unimodal section supporting only one mode coinciding with the first mode of said structure and coupled to each of said intrinsic bimodal cavities through common openings therebetween, said unimodal section forming a common composite resonant cavity for said first mode with all of the said intrinsic bimodal cavities; b. said single unimodal section including aperture means coupling the external source of microwave energy to said first mode; c. each aperture means of said intrinsic bimodal cavities capable of permitting respective spin samples to be introduced into them; d. each aperture means of said intrinsic bimodal cavities acting as respective second polarized coupling devices such that each of their second modes may be coupled to the respective external microwave detector.

Claim 7

Dependent Claim 275 words

In a spin induction spectrometer for magnetic resonance measurements on a spin sample: a. means defining a bimodal composite resonant microwave structure, including therein at least one multimode cylindrical cavity; and b. polarized coupling devices means for allowing exchange of microwave energy with an outside microwave generator and a detector respectively of only two orthogonal degenerate modes of the said multimode cavity such that with regard to microwave energy transfer in either way the multimode cavity serves as an overall bimodal cavity with well defined orthogonal degenerate modes; c. said first polarized coupling device being used to excite only the first mode of said overall bimodal cylindrical cavity this mode being used for stimulating the spins by coupling the external microwave energy to it; d. said second polarized coupling device being used for coupling only the second mode of said overall bimodal cylindrical cavity excited by the microwave energy irradiated by the stimulated spins at resonance to an external microwave detector; e. said overall bimodal cylindrical cavity having aperture means such that a spin sample may be introduced into it; f. said first mode being orthogonal to said second mode and thereby being decoupled therefrom; g. said two coupling devices being polarized at right angles and thereby being mutually decoupled therefrom; h. said overall bimodal cylindrical cavity being so oriented in an external static magnetic field such that throughout the volume occupied by said spin sample the direction of said static magnetic field is perpendicular to both orthogonal microwave magnetic field vectors of the two said modes; i. said two modes being pairs of decoupled degenerate orthogonal modes oscillating for any number of half wavelengths.

Claim 8

Dependent Claim 275 words

In a spin induction spectrometer for magnetic resonance measurements on a spin sample: a. means defining a bimodal composite resonant microwave structure, including therein at least one multimode cylindrical cavity; and b. polarized coupling devices means for allowing exchange of microwave energy with an outside microwave generator and a detector respectively of only two orthogonal degenerate modes of the said multimode cavity such that with regard to microwave energy transfer in either way the multimode cavity serves as an overall bimodal cavity with well defined orthogonal degenerate modes; c. said first polarized coupling device being used to excite only the first mode of said overall bimodal cylindrical cavity this mode being used for stimulating the spins by coupling the external microwave energy to it; d. said second polarized coupling device being used for coupling only the second mode of said overall bimodal cylindrical cavity excited by the microwave energy irradiated by the stimulated spins at resonance to an external microwave detector; e. said overall bimodal cylindrical cavity having aperture means such that a spin sample may be introduced into it; f. said first mode being orthogonal to said second mode and thereby being decoupled therefrom; g. said two coupling devices being polarized at right angles and thereby being mutually decoupled therefrom; h. said overall bimodal cylindrical cavity being so oriented in an external static magnetic field such that throughout the volume occupied by said spin sample the direction of said static magnetic field is perpendicular to both orthogonal microwave magnetic field vectors of the two said modes; i. said two modes being pairs of decoupled degenerate orthogonal modes oscillating for any number of half wavelengths.

Claim 9

Dependent Claim 36 words

A microwave composite structure as recited in claim 6, wherein said two polarizing coupling devices comprise two thin rectangular irises placed on the cavity walls, said irises determining unequivocally the bimodal character of said cylindrical cavity.

Claim 10

Dependent Claim 184 words

A microwave composite structure as recited in claim 6, wherein saiD structure: a. comprises one unimodal section supporting only one resonant mode and one said overall bimodal cylindrical cavity, said unimodal section being coupled to said overall bimodal cylindrical cavity through a common opening therebetween to form a common composite resonant cavity for one mode which coincides with said first mode of said overall bimodal cavity; b. said unimodal section forming said first polarized coupling device for said first mode of said overall bimodal cylindrical cavity; c. said unimodal section including aperture means coupling the external source of microwave energy to its mode, the microwave energy propagating from said unimodal section to said overall bimodal cylindrical cavity; d. said structure including means disposed between said unimodal section and said overall bimodal cylindrical cavity for reducing the coupling between said two modes at minimum, said means disposed between adjusting the microwave polarization plane of said unimodal section with respect to the polarization plane of the second mode of said overall cylindrical bimodal cavity through their mutual rotation about the cylindrical axis of said cylindrical cavity.

Claim 11

Dependent Claim 176 words

A microwave composite structure as recited in claim 6, wherein said structure: a. comprises one unimodal section supporting only one resonant mode and one said overall bimodal cylindrical cavity, said unimodal section being coupled to said cylindrical cavity through a common opening therebetween and forming a common composit resonant cavity for a single mode which coincides with said second mode of said overall bimodal cavity; b. said unimodal section forming said second polarized coupling device for said second mode of said overall bimodal cylindrical cavity, c. said unimodal section including aperture means for coupling its mode excited by the polarized radiation emitted by the stimulated spins to an external microwave detector; d. said structure including means disposed between said unimodal section and said overall bimodal cylindrical cavity for decreasing the coupling between said two modes, said means disposed between adjusting the microwave polarization plane of said unimodal section with respect to the polarization plane of the second mode of said overall bimodal cylindrical cavity through their mutual rotation about the cylindrical axis of said cylindrical cavity.

Claim 12

Dependent Claim 141 words

A microwave composite structure as recited in claim 6, wherein said polarized device includes a pair of elongated slots in the walls of said overall bimodal cylindrical cavity, said slots being elongated in a direction parallel to the magnetic lines of said second mode, signal combining means having three ports with two of said ports being connected to respective ones of said pair of slots for producing a combined output at the third port corresponding to a vector sum of the spin resonance signals extracted via said pair of slots from said second mode, said slots being placed in selected positions of selected cavity walls such that the directions of the vectors of the microwave magnetic fields of the first and second mode at their present positions have the same and opposite symmetry characteristics, respectively, with respect to the third port.

Claim 13

Dependent Claim 152 words

A microwave composite structure as recited in claim 8, wherein said structure comprises: a. a plurality of overall bimodal cylindrical cavities each capable of supporting said first and second modes, and a single unimodal section supporting only one mode coinciding with the first mode of said structure and coupled to each of said overall bimodal cavities through common openings therebetween said unimodal section forming a common composite resonant cavity for said first mode with all the said overall bimodal cylindrical cavities; b. said single unimodal section including aperture means coupling the external source of microwave energy to said first mode; c. said overall bimodal cylindrical cavity having aperture means such that respective spIn samples may be introduced into them; d. said overall bimodal cylindrical cavities each having aperture means acting as respective second polarized coupling devices such that each of their second modes may be coupled to the respective external microwave detector.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-05-07	1976-11-06	1977-05-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-05-07	1980-11-06	1981-05-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-05-07	1984-11-06	1985-05-08	$7700.00	Window Closed / Lapsed

Electron spin inductors at microwaves

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