Spectrometer Crystal Analyzer Alignment Method
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Solution Overview
Problem
Existing x-ray spectrometers with curved crystal analyzers (CCAs) often require time-consuming and costly two-axis tilt corrections due to miscut errors, which add complexity and cost, necessitating efficient alignment methods.
Innovation Solution
A method involving rotating the crystal analyzer about an axis within the instrument plane and tilting or translating the detector to align the reciprocal lattice vector with the radiation source and detector, eliminating the need for two-axis tilt corrections by using one-axis rotations and translations to achieve proper alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two-axis tilt correction is used to align the CCA, then alignment precision is improved, but alignment time and device complexity increase
Solution Approach 1:
The patent extracts the alignment problem into two independent components: (1) positioning the reciprocal lattice vector within the instrument plane via rotation, and (2) aligning it with the source-detector line via tilting/translation. This separation eliminates the need for complex two-axis tilt correction while achieving the same alignment precision.
Solution Approach 2:
The alignment process is segmented into distinct steps: first rotating the CCA about an axis in the instrument plane to bring the reciprocal lattice vector into the plane, then separately tilting the CCA or translating the detector to achieve proper alignment with the source-detector line. This segmentation simplifies the overall alignment procedure.
2Measurement precision
If two-axis tilt correction is used to align the CCA, then alignment precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes the need for two-axis tilt correction mechanisms by extracting the alignment into simpler components: a single rotation to position the reciprocal lattice vector in the instrument plane, followed by a single tilt or translation to align with the source-detector line. This reduces mechanical complexity while maintaining precision.
Solution Approach 2:
The patent replaces complex mechanical two-axis tilt correction systems with simpler mechanical rotations combined with detector translations, reducing the need for complex motorized micrometers and multi-axis adjustment mechanisms.
3Measurement precision
If two-axis tilt correction is used, then alignment precision is improved, but ease of operation deteriorates
Solution Approach 1:
The alignment operation is divided into clear, sequential steps: rotate the CCA to bring the reciprocal lattice vector into the instrument plane, then tilt or translate to align with the source-detector line. This segmented approach is easier to operate than simultaneous two-axis tilt corrections.
Solution Approach 2:
The patent performs preliminary rotation to position the reciprocal lattice vector within the instrument plane before performing the final alignment tilt or translation. This preliminary action simplifies the subsequent alignment step and makes the overall operation easier to execute.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces alignment time and cost by allowing for quicker and more straightforward alignment of spectrometers, potentially eliminating the need for repeated alignment procedures with the same CCA, thus enhancing operational efficiency.
Implementation Method 1
The crystallographic orientation of the wafer surface is chosen so that the spacing between crystal planes nominally parallel to the surface is appropriate, via Bragg's law, to generate constructive interference of x-rays within the energy or wavelength range of interest.
Data Source
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AI summary
An example method for aligning a spectrometer is described herein. The spectrometer includes a radiation source, a crystal analyzer, and a detector that are all positioned on an instrument plane. The method includes rotating the crystal analyzer about an axis that is within the instrument plane and perpendicular to a rotation plane such that (i) a reciprocal lattice vector of the crystal analyzer is within the instrument plane or (ii) a component of the reciprocal lattice vector within the rotation plane is perpendicular to the instrument plane. An origin of the reciprocal lattice vector is located on the axis. The method further includes tilting the crystal analyzer or translating the detector such that the reciprocal lattice vector bisects a line segment that is bounded by the detector and the radiation source. Example spectrometers related to the example method are also disclosed.