US3736426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of and apparatus for inspecting crystals
Assignee: AT&T Inc
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Filing: 1972-03-01
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Granted: 1973-05-29
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Expires: 1992-03-01
Abstract
Abstract In order to determine the angular orientation of atomic planes in a crystal relative to a reference surface thereof, the crystal is inspected by an X-ray defraction technique in which a pair of X-ray beams are sequentially passed through the crystal from opposite directions while the crystal is rotated through a small arc and monitored for Bragg angle reflections. The two angles at which reflections occur are then averaged to determine an average Bragg angle of reflection. This technique compensates for the situation in which the atomic planes of the crystal are completely oblique to the reference surface by cancelling component vectors of reflection introduced by the complete obliqueness.
Inventors
- 👤 A Anderson
- 👤 R Grenier
- 👤 P Perri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:33
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/20; G01N23/207
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
In a method of measuring the axial orientation of atomic planes in a crystal relative to a reference surface of the crystal where the atomic planes may be completely oblique relative to the reference surface, comprising the steps of: rotating the crystal about an axis thereof through an arc, passing radiant energy through a reference surface of the crystal while the crystal is being rotated, determining the angle of rotation at which radiant energy is reflected through the reference surface of the crystal from the atomic planes, storing the determined angle, passing radiant energy through a surface of the crystal opposite the reference surface, determining the angle of rotation at which radiant energy is reflected through the opposite surface from the atomic planes, and averaging the angle at which radiant energy is reflected through the opposite surface with the stored angle to compensate for inaccuracies introduced into the measurements because of the complete obliqueness.
Claim 2
Dependent Claim
154 words
In a method of measuring the axial orientation of atomic planes in a crystal relative to a reference surface of the crystal where the atomic planes may be completely oblique relative to the reference surface, comprising the steps of: rotating the crystal about an axis thereof through an arc, passing radiant energy through a reference surface of the crystal while the crystal is being rotated, determining the angle of rotation at which radiant energy is reflected through the reference surface of the crystal from the atomic planes, storing the determined angle, passing radiant energy through a surface of the crystal opposite the reference surface, determining the angle of rotation at which radiant energy is reflected through the opposite surface from the atomic planes, and averaging the angle at which radiant energy is reflected through the opposite surface with the stored angle to compensate for inaccuracies introduced into the measurements because of the complete obliqueness.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the radiation employed is X-radiation.
Claim 4
Dependent Claim
120 words
In a method of determining the axial orientation of atomic planes in a crystal wherein the crystal is rotated through a sector intersected by an X-ray beam which is, in turn, monitored for reflections through one surface of the crystal from the atomic planes to determine the angle at which reflections occur, the improvement comprising the steps of: again rotating the crystal, impinging an additional X-ray beam through another surface of the crystal, monitoring the X-ray beam for reflections from the atomic planes through the other surface to determine the angle at which the reflections occur, and averaging the angles at which reflections occur through both the surfaces to determine the axial orientation of the atomic planes in the crystal.
Claim 5
Dependent Claim
120 words
In a method of determining the axial orientation of atomic planes in a crystal wherein the crystal is rotated through a sector intersected by an X-ray beam which is, in turn, monitored for reflections through one surface of the crystal from the atomic planes to determine the angle at which reflections occur, the improvement comprising the steps of: again rotating the crystal, impinging an additional X-ray beam through another surface of the crystal, monitoring the X-ray beam for reflections from the atomic planes through the other surface to determine the angle at which the reflections occur, and averaging the angles at which reflections occur through both the surfaces to determine the axial orientation of the atomic planes in the crystal.
Claim 6
Dependent Claim
109 words
In an apparatus for determining the angle of orientation of atomic planes in a crystal relative to a reference surface of the crystal, means for sequentially focusing oppositely directed X-ray beams for passage into the crystal, means for angularly displacing the crystal relative to the X-ray beams, means for detecting Bragg angle X-ray reflections from the crystal, means for determining the angular positions of the Rystal at which Bragg angle reflections occur from the crystal, and means for averaging the angular positions at which Bragg angle reflections occur to determine the angle of orientation of the atomic planes in the crystal relative to the reference surface of the crystal.
Claim 7
Dependent Claim
109 words
In an apparatus for determining the angle of orientation of atomic planes in a crystal relative to a reference surface of the crystal, means for sequentially focusing oppositely directed X-ray beams for passage into the crystal, means for angularly displacing the crystal relative to the X-ray beams, means for detecting Bragg angle X-ray reflections from the crystal, means for determining the angular positions of the Rystal at which Bragg angle reflections occur from the crystal, and means for averaging the angular positions at which Bragg angle reflections occur to determine the angle of orientation of the atomic planes in the crystal relative to the reference surface of the crystal.
Claim 8
Dependent Claim
29 words
The apparatus of claim 4 further including means responsive to said averaging means for directing the crystal to a selected location after the average angular position has been computed.
Claim 9
Independent Claim
132 words
An apparatus for determining the angle of orientation of atomic planes relative to an axis of a reference surface of a crystal comprising: means for passing sequentially a pair of X-ray beams through the crystal from generally opposite directions, means for oscillating the crystal about the axis while the X-ray beams are impinging thereon, means for detecting Bragg angle reflections from the crystal while the crystal is oscillating, means for determining when the reflections reach a predetermined level of intensity, means for computing the mean of the angles at which reflections occur from the crystal after the reflections reach a predetermined level of intensity, and means for averaging the mean angles after the angles are computed to determine the angle which the atomic planes make with the reference surface of the crystal.
Claim 10
Independent Claim
132 words
An apparatus for determining the angle of orientation of atomic planes relative to an axis of a reference surface of a crystal comprising: means for passing sequentially a pair of X-ray beams through the crystal from generally opposite directions, means for oscillating the crystal about the axis while the X-ray beams are impinging thereon, means for detecting Bragg angle reflections from the crystal while the crystal is oscillating, means for determining when the reflections reach a predetermined level of intensity, means for computing the mean of the angles at which reflections occur from the crystal after the reflections reach a predetermined level of intensity, and means for averaging the mean angles after the angles are computed to determine the angle which the atomic planes make with the reference surface of the crystal.
Claim 11
Dependent Claim
25 words
The apparatus of claim 6 further including means for rejecting the crystal if the Bragg angle reflections do not reach the predetermined level of intensity.
References Cited (Backward Citations)
US3448265A
Cited
US3649831A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |