Diffractometer with multiple radiation detectors and calibration tool and calibration method

Abstract

Disclosed herein is a system comprising: an image sensor comprising M (Mgt; 1) a radiation detector, each of the M radiation detectors comprising a two-dimensional array of sensing elements; a radiation source; a calibration plate having N calibration patterns and configured to be located at a first position between the image sensor and the radiation source; and a controller configured to determine a relative position and orientation of each of the M radiation detectors based on an image captured by each of the M radiation detectors of the M images. The radiation source is configured to transmit a first radiation beam toward the calibration plate at a first position. The M radiation detectors are configured to capture M calibration pattern images of the N calibration patterns, respectively. The N calibration patterns of the calibration plate are at least two different pattern types.

Description

Background Art

[0001] A radiation detector is a device that measures properties of radiation. Examples of properties may include the spatial distribution of intensity, phase, and polarization of the radiation. The radiation measured by a radiation detector may be radiation that has passed through an object. The radiation measured by a radiation detector may be electromagnetic radiation, such as infrared light, visible light, ultraviolet light, X-rays, or gamma rays. The radiation may be of other types, such as alpha and beta rays. A diffractometer may have multiple radiation detectors, which may need to be calibrated for their relative positions and orientations. Summary of the invention

[0002] A system is disclosed herein, comprising: an image sensor, comprising M radiation detectors arranged in K rows, M being an integer greater than 1, and K being a positive integer, wherein each of the M radiation detectors comprises a two-dimensional array of sensing elements; a first radiation source; a calibration plate, (A) comprising N calibration patterns, and (B) configured to be located at a first position between the image sensor and the first radiation source, wherein the first radiation source is configured to send a first radiation beam from the first radiation source toward the calibration plate located at the first position, wherein the M radiation detectors are configured to respectively capture M calibration pattern images of the N calibration patterns based on an interaction between the first radiation beam and the N calibration patterns of the calibration plate, and wherein the N calibration patterns of the calibration plate are at least (A) a first pattern type and (B) a second pattern type; and a controller, configured to determine the relative position and orientation of each of the radiation detectors based on an image in the M images captured by each of the M radiation detectors.

[0003] In one aspect, the N calibration patterns of the calibration plate are arranged into K strips, and the K strips are respectively parallel to and correspond to K rows of radiation detectors; each of the K strips includes P rows and multiple columns of calibration patterns; and in each of the M images, at least one array consisting of P rows and Q columns of calibration patterns located within a strip of the K strips among the N calibration patterns is captured.

[0004] In one aspect, any array consisting of P rows and Q columns of calibration patterns located within any stripe of K stripes among the N calibration patterns is unique in terms of the arrangement of the first type of calibration patterns and the second type of calibration patterns in any array, where P and Q are positive integers.

[0005] In one aspect, P=Q=3.

[0006] In one aspect, the N calibration patterns of the calibration plate are respectively N circular holes of two different sizes corresponding to the first pattern type and the second pattern type on the calibration plate.

[0007] In one aspect, K>1.

[0008] In one aspect, the first radiation source includes a sample stage for holding the sample, and the system further includes a second radiation source configured to transmit a second radiation beam from the second radiation source to the sample, thereby causing the sample to transmit the first radiation beam.

[0009] In one aspect, the first radiation beam and the second radiation beam are X-ray beams.

[0010] In one aspect, the calibration plate is configured to be located in the second position such that the calibration plate does not block a path of a third radiation beam traveling from the first radiation source to the M radiation detectors of the image sensor.

[0011] In one aspect, the calibration plate is configured to rotate from a first position to a second position.

[0012] In one aspect, the calibration plate is configured to rotate from a first position to a second position about an axis of rotation that intersects the first radiation source.

[0013] In one aspect, the calibration plate has the shape of a curved surface of a cylinder, the axis of the cylinder intersecting the first radiation source.

[0014] A method is disclosed herein, comprising: sending a first radiation beam from a first radiation source toward a calibration plate located at a first position between an image sensor and the first radiation source, wherein the image sensor comprises M radiation detectors arranged in K rows, M is an integer greater than 1, and K is a positive integer, wherein each of the M radiation detectors comprises a two-dimensional array of sensing elements, and wherein the calibration plate comprises N calibration patterns; utilizing the M radiation detectors to respectively capture M calibration pattern images of the N calibration patterns based on an interaction between the first radiation beam and the N calibration patterns of the calibration plate, wherein the N calibration patterns of the calibration plate are at least (A) a first pattern type and (B) a second pattern type; and utilizing a controller to determine the relative position and orientation of each of the radiation detectors based on an image in the M images captured by each of the M radiation detectors.

[0015] In one aspect, the N calibration patterns of the calibration plate are arranged into K strips, which are respectively parallel to and correspond to K rows of radiation detectors; each of the K strips includes P rows and multiple columns of calibration patterns; and in each of the M images, at least one array consisting of P rows and Q columns of calibration patterns located within a strip of the K strips among the N calibration patterns is captured.

[0016] In one aspect, any array consisting of P rows and Q columns of calibration patterns located within any stripe of K stripes among the N calibration patterns is unique in terms of the arrangement of the first type of calibration patterns and the second type of calibration patterns in any array, where P and Q are positive integers.

[0017] In one aspect, P=Q=3.

[0018] In one aspect, the N calibration patterns of the calibration plate are respectively N circular holes of two different sizes corresponding to the first pattern type and the second pattern type on the calibration plate.

[0019] In one aspect, K>1.

[0020] In one aspect, the first radiation source includes a sample stage for holding the sample, and emitting the first radiation beam includes using a second radiation source to send a second radiation beam from the second radiation source to the sample, thereby causing the sample to transmit the first radiation beam.

[0021] In one aspect, the first radiation beam and the second radiation beam are X-ray beams.

[0022] In one aspect, the method further includes positioning the calibration plate in a second position after performing the capturing of the M images so that the calibration plate does not block a path of a third radiation beam traveling from the first radiation source to the M radiation detectors of the image sensor.

[0023] In one aspect, positioning the calibration plate includes rotating the calibration plate from a first position to a second position.

[0024] In one aspect, the calibration plate is rotated about an axis of rotation that intersects the first radiation source.

[0025] In one aspect, the calibration plate has the shape of a curved surface of a cylinder, the axis of the cylinder intersecting the first radiation source. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A radiation detector according to an embodiment is schematically shown.

[0027] Figure 2 A simplified cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0028] Figure 3 A detailed cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0029] Figure 4 A detailed cross-sectional view of a radiation detector according to an alternative embodiment is schematically shown.

[0030] Figure 5-Figure 6 Different views of an imaging system according to an embodiment are schematically shown.

[0031] Figure 7 A calibration tool for an imaging system according to an embodiment is shown.

[0032] Figure 8 A flow chart outlining a calibration operation for an imaging system is shown according to an embodiment. DETAILED DESCRIPTION

[0033] Radiation Detectors

[0034] As an example, Figure 1 The radiation detector 100 is schematically shown. The radiation detector 100 may include a two-dimensional array of pixels 150 (also referred to as sensing elements 150). The array may be a rectangular array (e.g. Figure 1 as shown), a honeycomb array, a hexagonal array, or any other suitable array. Figure 1 The array of pixels 150 in the example of FIG. 1 has 4 rows and 7 columns; however, in general, the array of pixels 150 may have any number of rows and any number of columns.

[0035] Each pixel 150 can be configured to detect radiation from a radiation source (not shown) incident thereon, and can be configured to measure the characteristics of the radiation (e.g., the energy, wavelength, and frequency of the particles). The radiation may include radiation particles such as photons (X-rays, gamma rays, etc.) and subatomic particles (alpha particles, beta particles, etc.). Each pixel 150 can be configured to count the number of radiation particles incident thereon over a period of time and whose energy falls into a plurality of energy bins. All pixels 150 can be configured to count the number of radiation particles incident thereon and falling into a plurality of energy bins over the same period of time. When the incident radiation particles have similar energies, the pixel 150 can be simply configured to count the number of radiation particles incident thereon over a period of time without measuring the energy of each radiation particle.

[0036] Each pixel 150 can have its own analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident radiation particle into a digital signal, or to digitize an analog signal representing the total energy of multiple incident radiation particles into a digital signal. The pixels 150 can be configured to operate in parallel. For example, when one pixel 150 measures an incident radiation particle, another pixel 150 may be waiting for the radiation particle to arrive. The pixels 150 do not have to be individually addressable.

[0037] The radiation detector 100 described herein may have applications such as: X-ray telescopes, X-ray mammography, industrial X-ray defect detection, X-ray microscopy or microradiography, X-ray casting inspection, X-ray nondestructive testing, X-ray weld inspection, X-ray digital subtraction angiography, etc. It may be appropriate to use such a radiation detector 100 instead of a photographic plate, photographic film, a photo-stimulated phosphor plate (PSP plate), an X-ray image intensifier, a scintillator, or another semiconductor X-ray detector.

[0038] Figure 2 Schematically illustrating the Figure 1 2-2. Specifically, the radiation detector 100 may include a radiation absorbing layer 110 and an electronic layer 120 (which may include one or more ASICs or application specific integrated circuits), and the electronic layer 120 is used to process and analyze the electrical signal generated in the radiation absorbing layer 110 by the incident radiation. The radiation detector 100 may or may not include a scintillator (not shown). The radiation absorbing layer 110 may include a semiconductor material such as silicon, germanium, GaAs, CdTe, CdZnTe or a combination thereof. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest.

[0039] As an example, Figure 3 Schematically shows Figure 1 Detailed cross-sectional view of the radiation detector 100 along line 2-2. Specifically, the radiation absorbing layer 110 may include one or more diodes (e.g., pin or pn) formed by one or more discrete regions 114 of the first doping region 111, the second doping region 113. The second doping region 113 may be separated from the first doping region 111 by an optional intrinsic region 112. The discrete regions 114 may be separated from each other by the first doping region 111 or the intrinsic region 112. The first doping region 111 and the second doping region 113 may have opposite types of doping (e.g., the first doping region 111 is p-type and the second doping region 113 is n-type; or the first doping region 111 is n-type and the second doping region 113 is p-type). Figure 3 In the example of , each discrete region 114 of the second doped region 113 forms a diode with the first doped region 111 and the optional intrinsic region 112. That is, in Figure 3 In the example of FIG. 1 , the radiation absorbing layer 110 has a plurality of diodes (more specifically, 7 diodes corresponding to Figure 1 The array has 7 pixels in one row 150, for simplicity, in Figure 3 Only two pixels 150 are marked in FIG. 1 . The plurality of diodes may have an electrical contact 119A as a shared (common) electrode. The first doped region 111 may also have a plurality of discrete portions.

[0040] The electronic layer 120 may include an electronic system 121 suitable for processing or interpreting signals generated by radiation incident on the radiation absorption layer 110. The electronic system 121 may include analog circuits such as filter networks, amplifiers, integrators, and comparators, or digital circuits such as microprocessors and memories. The electronic system 121 may include one or more ADCs (analog-to-digital converters). The electronic system 121 may include components shared by multiple pixels 150 or components dedicated to a single pixel 150. For example, the electronic system 121 may include an amplifier dedicated to each pixel 150 and a microprocessor shared between all pixels 150. The electronic system 121 may be electrically connected to the pixel 150 through the through hole 131. The space between the through holes may be filled with a filling material 130, which may increase the mechanical stability of the connection of the electronic layer 120 to the radiation absorption layer 110. Other bonding techniques may connect the electronic system 121 to the pixel 150 without using the through hole 131.

[0041] When radiation from a radiation source (not shown) strikes the radiation absorption layer 110 including the diode, the radiation particles may be absorbed and generate one or more carriers (e.g., electrons, holes) through a variety of mechanisms. The carriers may drift to one of the electrodes of the diodes under the action of an electric field. The electric field may be an external electric field. The electrical contact 119B may include a plurality of discrete portions, each of which is in electrical contact with the discrete region 114. The term "electrical contact" may be used interchangeably with the term "electrode". In one embodiment, the carriers may drift in a plurality of directions, and the carriers generated by a single radiation particle are substantially not shared by two different discrete regions 114 (here, "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these carriers flow to a discrete region 114 different from the discrete region to which the remaining carriers flow). The carriers generated by radiation particles incident around the footprint of one of the discrete regions 114 are substantially not shared by another of the discrete regions 114. A pixel 150 associated with a discrete region 114 may be an area around the discrete region 114 in which substantially all (more than 98%, more than 99.5%, more than 99.9%, or more than 99.99%) of the carriers generated by radiation particles incident therein flow toward the discrete region 114. That is, less than 2%, less than 1%, less than 0.1%, or less than 0.01% of the carriers flow out of the pixel 150.

[0042] Figure 4 Schematically illustrating an alternative embodiment Figure 1Detailed cross-sectional view of radiation detector 100 along line 2-2. More specifically, radiation absorbing layer 110 may include resistors of semiconductor materials such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof, but not diodes. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest. In one embodiment, Figure 4 The electronic layer 120 is similar in structure and function to Figure 3 The electron layer is 120.

[0043] When radiation strikes the radiation absorbing layer 110, which includes a resistor but does not include a diode, it can be absorbed and generate one or more carriers through a variety of mechanisms. One radiation particle can generate 10 to 100,000 carriers. The carriers can drift to the electrical contacts 119A and 119B under the action of the electric field. The electric field can be an external electric field. The electrical contact 119B can include multiple discrete portions. In one embodiment, the carriers can drift in multiple directions and make the carriers generated by a single radiation particle substantially not shared by two different discrete portions of the electrical contact 119B (here "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1% or less than 0.01% of these carriers flow to a discrete portion of the multiple discrete portions that is different from the discrete portion to which the remaining carriers flow). The carriers generated by radiation particles incident on the footprint of one of the discrete portions of the electrical contact 119B are substantially not shared by another of the discrete portions of the electrical contact 119B. A pixel 150 associated with a discrete portion of the electrical contact 119B may be an area around the discrete portion in which substantially all (more than 98%, more than 99.5%, more than 99.9%, or more than 99.99%) of the carriers generated by radiation particles incident therein flow toward the discrete portion of the electrical contact 119B. That is, less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of the carriers flow out of the pixel associated with the discrete portion of the electrical contact 119B.

[0044] Imaging System

[0045] Figure 5 and Figure 6 A top view and a perspective view of an imaging system 500 according to an embodiment are schematically shown, respectively. In an embodiment, the imaging system 500 may include an image sensor 510, a calibration tool 520, a sample stage 530, a radiation source 540, and a controller 550.

[0046] Image Sensor

[0047] In one embodiment, reference Figure 5 and Figure 6, the image sensor 510 may include M radiation detectors that may be arranged into K rows of radiation detectors, where M is an integer greater than 1, and K is a positive integer (e.g., Figure 5 and Figure 6 As shown, M=24, K=2). In one embodiment, the upper row of radiation detectors may include 12 radiation detectors 100a1-100a12, and the lower row of radiation detectors may include 12 radiation detectors 100b1-100b12.

[0048] exist Figure 5 In the (top view), 12 radiation detectors 100a1-100a12 (i.e., upper row) are shown, however, 12 radiation detectors 100b1-100b12 (i.e., lower row) are not shown because they are respectively located below the radiation detectors 100a1-100a12 and are therefore blocked and not visible.

[0049] exist Figure 6 In the (perspective view), regarding the upper row of radiation detectors, for the sake of simplicity, only two radiation detectors 100a1 and 100a2 are shown (i.e., the remaining 10 radiation detectors 100a3-100a12 are not shown). Regarding the lower row of radiation detectors, for the sake of simplicity, only radiation detector 100b1 is shown (i.e., the remaining 11 radiation detectors 100b2-100b12 are not shown).

[0050] In one embodiment, each of the 24 radiation detectors 100a1-100b12 of the image sensor 510 may be similar in structure and function to Figure 1-Figure 4 A radiation detector 100 is provided.

[0051] Calibration tool - calibration board

[0052] In one embodiment, reference Figure 5 and Figure 6 , the calibration tool 520 may include a calibration plate 525. In one embodiment, for a calibration operation of the 24 radiation detectors 100a1-100b12 of the image sensor 510, the calibration plate 525 may be positioned in a first position relative to the image sensor 510 and the sample stage 530, such that the calibration plate 525 is located between the image sensor 510 and the sample stage 530 (as shown).

[0053] Calibration pattern: 2 different sized holes arranged in a strip

[0054] In one embodiment, the calibration plate 525 may include N circular holes of two different sizes (large and small), where N is a positive integer (eg, N=435).

[0055] In one embodiment, the 435 holes of the calibration plate 525 may be arranged into K strips, which may be parallel to and correspond to the K rows of radiation detectors of the image sensor 510. Note that in the example described above, K=2. Therefore, the K strips include an upper strip and a lower strip, such as Figure 6 shown.

[0056] To illustrate, Figure 6 As shown, an area 527 of the calibration plate 525 is magnified in view. Figure 7 All 435 holes of calibration plate 525 are shown in FIG.

[0057] In one embodiment, reference Figure 5-Figure 7 , the upper strip may include a P×Q1 array consisting of P rows and Q1 columns of holes, and the lower strip may include a P×Q2 array consisting of P rows and Q2 columns of holes, where P, Q1, and Q2 are integers greater than 1 (for example, P=3, Q1=72, Q2=73, so that the total number of holes on the calibration plate 525 is N=3×72+3×73=435).

[0058] Any P×Q Array in a Strip is Unique In one embodiment, any P×Q array consisting of P rows and Q columns of holes in any strip can be unique for all 435 holes of the calibration plate 525 in terms of the arrangement of large holes and small holes in any P×Q array, where Q is a positive integer (e.g., P=Q=3). For P=Q=3, this means that any 3×3 array consisting of multiple holes in any strip is unique for all 435 holes of the calibration plate 525 in terms of the arrangement of large holes and small holes in any 3×3 array.

[0059] For example, the upper strip may include the following Q1=72 columns of 3 holes: 012345676543210246135753164203614725274163041526373624130516273437261506.

[0060] Note that each decimal digit of the 72-digit string represents the number of large holes in the corresponding column and its position in the column. For example, the fourth decimal digit "3" of the 72-digit string indicates that there are 2 large holes in the fourth column, and their positions are the first and second positions from the bottom up (such as Figure 6 527).

[0061] The lower strip may include 3 holes in the following Q2=73 columns: 0011223344556677665544332211002244661133557755331166442200336633007744114.

[0062] Note that each decimal digit of the 73-digit string represents the number of large holes in the corresponding column and its position in the column. For example, the sixth decimal digit "2" of the 73-digit string represents that there is 1 large hole in the sixth column, and their position is the second position from the bottom up (such as Figure 6 527 in the enlarged area 527).

[0063] Note that any combination of 3 consecutive numbers in the above 2 strings is unique among all possible combinations of 3 consecutive numbers in all 145 numbers of the two strings. In other words, any 3×3 array of holes in 3 rows and 3 columns in any strip is unique for all N=435 holes of calibration plate 525 in terms of the arrangement of large and small holes in any 3×3 array.

[0064] For example, refer to Figure 6 , the 3×3 array 525a1′ (ie, 123) is unique to the above 72-digit string and 73-digit string. In other words, searching for the combination “123” in the 72-digit string and the 73-digit string will only produce a single result.

[0065] As another example, the 3×3 array 525b1′ (ie, 112) is unique to the 72-digit string and the 73-digit string above. In other words, searching for the combination “112” in the 72-digit string and the 73-digit string will only produce a single result.

[0066] Each radiation detector captures in each image at least one P×Q array consisting of a plurality of holes located in a certain strip.

[0067] In one embodiment, a radiation beam 534 (eg, a diverging beam) may be sent from the sample stage 530 toward the calibration plate 525. Then, the 24 radiation detectors 100a1-100b12 of the image sensor 510 may respectively capture 24 hole images of the 435 holes of the calibration plate 525.

[0068] In one embodiment, at least one P×Q array consisting of P rows and Q columns of holes located in a stripe may be captured in each of the 24 images, where Q is a positive integer (eg, P=Q=3).

[0069] For example, refer to Figure 6, assuming that the radiation detector 100a1 captures in the image an area 525a1 of the calibration plate 525. Note that the radiation detector 100a1 captures in the image a 3x3 array 525a1' consisting of a plurality of holes located in the upper stripe.

[0070] For example, refer to Figure 6 , assuming that the radiation detector 100b1 captures in the image an area 525b1 of the calibration plate 525. Note that the radiation detector 100b1 captures in the image a 3×3 array 525b1 ′ consisting of a plurality of holes located in the lower stripe.

[0071] Sample stage and radiation source

[0072] In one embodiment, reference Figure 5 and Figure 6 , sample 532 (in Figure 5 shown in Figure 6 534. In one embodiment, a radiation source 540 may transmit a radiation beam 542 toward a sample 532, and the sample 532 may diffract or scatter the radiation beam 542, thereby generating a radiation beam 534.

[0073] In other words, the sample stage 530 and the sample 532 can act as a radiation source that sends a radiation beam (such as radiation beam 534) toward the calibration plate 525 located in the first position (ie, between the sample stage 530 and the image sensor 510).

[0074] refer to Figure 5 and Figure 6 Although radiation source 540 is shown as a point, radiation source 540 may have any size and shape (ie, radiation source 540 is not necessarily a point source).

[0075] In an embodiment, both radiation beam 542 and radiation beam 534 may be X-ray beams.

[0076] Controller - Calibration Operation

[0077] In one embodiment, reference Figure 5 and Figure 6 , the controller 550 may be electrically coupled to the image sensor 510. In one embodiment, the controller 550 may be configured to determine the relative position and orientation of each of the 24 radiation detectors 100a1-100b12 based on the at least one 3×3 array of multiple holes located in a strip captured by each of the radiation detectors in the image.

[0078] For example, the controller 550 can determine the relative position and orientation of the radiation detector 100a1 based on the 3×3 array 525a1′ composed of multiple holes located in the upper strip. Specifically, when the controller 550 receives an image (one of the 24 images mentioned above) taken by the radiation detector 100a1, the controller 550 can search for large holes and small holes in the image, and thereby accurately locate the 3×3 array 525a1′ composed of large holes and small holes in the image. Next, the controller 550 can convert the 3×3 array 525a1′ composed of multiple holes into a decimal combination “123”, and then search for the combination “123” in the above 72-digit string and the 73-digit string, and find the combination near the starting point of the 72-digit string. Based on the search result, the controller 550 can determine that the radiation detector 110a is located near the starting point of the upper row of radiation detectors. Also based on the arrangement of the apertures of the 3×3 array 525 a 1 ′ in the image captured by the radiation detector 100 a 1 , the controller 550 can determine the precise relative position and orientation of the radiation detector 100 a 1 .

[0079] As another example, the controller 550 may determine the relative position and orientation of the radiation detector 100b1 based on a 3×3 array 525b1 ′ composed of a plurality of apertures in the lower strip.

[0080] Flowchart outlining the calibration operation

[0081] Figure 8 The generalization according to the embodiment is shown Figure 5 — Figure 6 Flowchart 800 of a calibration operation of the imaging system 500 .

[0082] In step 810, operations may include sending a first radiation beam from a first radiation source toward a calibration plate located at a first position between an image sensor and the first radiation source. The image sensor includes M radiation detectors arranged in K rows, M is an integer greater than 1, and K is a positive integer. Each of the M radiation detectors includes a two-dimensional array of sensing elements. The calibration plate includes N calibration patterns.

[0083] For example, in the embodiments described above, reference Figure 5 and Figure 6 A first radiation beam 534 is sent from a first radiation source (sample stage 530 and sample 532) toward a calibration plate 525 located at a first position between the image sensor 510 and the first radiation source. The image sensor 510 includes 24 radiation detectors 100a1-100b12 arranged in 2 rows.

[0084] In step 820, the operation may include using M radiation detectors to respectively capture M calibration pattern images of N calibration patterns based on the interaction between the first radiation beam and the N calibration patterns of the calibration plate. The N calibration patterns of the calibration plate are at least (A) a first pattern type and (B) a second pattern type.

[0085] For example, in the embodiments described above, reference Figure 5 and Figure 6 , the 24 radiation detectors 100a1-100b12 respectively capture 24 hole images of the 435 holes based on the interaction between the first radiation beam 534 and the 435 holes. The 435 holes of the calibration plate 525 are at least (A) large hole type and (B) small hole type.

[0086] In step 830, operations may include determining, with a controller, a relative position and orientation of each of the M radiation detectors based on images captured by each of the M radiation detectors in the M images.

[0087] For example, in the embodiments described above, reference Figure 5 and Figure 6 , the controller 550 determines the relative position and orientation of the radiation detector 100a1 based on the image (one of the 24 images) taken by the radiation detector 100a1.

[0088] Other embodiments

[0089] Second Position of the Calibration Plate—Diffractometer

[0090] In one embodiment, reference Figure 5 and Figure 6 , the calibration plate 525 can be located in a second position (not shown) relative to the image sensor 510 and the sample stage 530 so that the calibration plate 525 does not block the path of the radiation beam traveling from the sample 532 on the sample stage 530 to the 24 radiation detectors 100a1-100b12 of the image sensor 510.

[0091] In one embodiment, the calibration plate 525 can be moved from a first position (eg, Figure 5 and Figure 6 For example, calibration plate 525 can be rotated 180 degrees around axis 536 from the first position to the second position.

[0092] In one embodiment, when the calibration plate 525 is in the second position, the imaging system 500 can operate as a diffractometer.

[0093] Shape of the calibration plate

[0094] In one embodiment, reference Figure 5 and Figure 6 , the calibration plate 525 may have a shape of a curved surface of a cylinder whose axis intersects with the sample stage 530 .

[0095] In one embodiment, the axis of the cylinder may be colinear with the axis 536 , and the calibration plate 525 rotates around the axis 536 from the first position to the second position.

[0096] Alternative Embodiments and Overview

[0097] In the embodiments described above, reference is made to Figure 5 and Figure 6 , calibration plate 525 includes N circular holes of 2 different sizes (large and small). Generally speaking, calibration plate 525 may include N calibration patterns of 2 different pattern types. For example, calibration plate 525 may include N holes of 2 different shapes (square and circular). For another example, calibration plate 525 may include N circular indentations of 2 different sizes (large and small).

[0098] In the embodiments described above, reference is made to Figure 5 and Figure 6 , the calibration plate 525 includes N calibration patterns of 2 different types (large holes and small holes). Alternatively, the calibration plate 525 may include N calibration patterns of 3 or more different pattern types. For example, the 3 different types can be square holes, triangular holes, and round holes. For another example, the 3 different types can be large holes, medium holes, and small holes.

[0099] While various aspects and embodiments are disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A system comprising: An image sensor comprising M radiation detectors arranged in K rows, M being an integer greater than 1, and K being a positive integer, wherein each of the M radiation detectors comprises a two-dimensional array of sensing elements; A first radiation source; a calibration plate, (A) comprising N calibration patterns, and (B) configured to be located at a first position between the image sensor and the first radiation source, wherein the first radiation source is configured to send a first radiation beam from the first radiation source toward the calibration plate located at the first position, wherein the M radiation detectors are configured to respectively capture M calibration pattern images of the N calibration patterns based on the interaction between the first radiation beam and the N calibration patterns of the calibration plate, and wherein the N calibration patterns of the calibration plate are at least (A) a first pattern type and (B) a second pattern type; and A controller is configured to determine a relative position and orientation of each of the M radiation detectors based on the image among the M images captured by each of the M radiation detectors.

2. The system according to claim 1, in, The N calibration patterns of the calibration plate are arranged into K strips, and the K strips are respectively parallel to and corresponding to the K rows of radiation detectors. Each of the K stripes includes P rows and multiple columns of calibration patterns, and In each of the M images, at least one array consisting of calibration patterns of P rows and Q columns located in a stripe of the K stripes among the N calibration patterns is captured.

3. The system of claim 2, wherein: Any array consisting of P rows and Q columns of calibration patterns among the N calibration patterns located in any stripe of the K stripes is unique in terms of the arrangement of the first type of calibration patterns and the second type of calibration patterns in any array, where P and Q are positive integers.

4. The system of claim 3, wherein: P=Q=3.

5. The system of claim 1, wherein: The N calibration patterns of the calibration plate are respectively N circular holes of two different sizes on the calibration plate corresponding to the first pattern type and the second pattern type.

6. The system of claim 1, wherein: K>1。 7. The system of claim 1, in, The first radiation source includes a sample stage for fixing a sample, and Wherein, the system further comprises a second radiation source, wherein the second radiation source is configured to transmit a second radiation beam from the second radiation source to the sample, thereby causing the sample to transmit the first radiation beam.

8. The system of claim 7, wherein: The first radiation beam and the second radiation beam are X-ray beams.

9. The system of claim 1, wherein: The calibration plate is configured to be located in a second position such that the calibration plate does not block a path of a third radiation beam traveling from the first radiation source to the M radiation detector of the image sensor.

10. The system of claim 9, wherein: The calibration plate is configured to rotate from the first position to the second position.

11. The system of claim 10, wherein: The calibration plate is configured to rotate from the first position to the second position about an axis of rotation that intersects the first radiation source.

12. The system of claim 1, wherein: The calibration plate has a shape of a curved surface of a cylinder, and an axis of the cylinder intersects the first radiation source.

13. A method comprising: sending a first radiation beam from a first radiation source toward a calibration plate at a first position between an image sensor and the first radiation source, The image sensor comprises M radiation detectors arranged in K rows, M is an integer greater than 1, and K is a positive integer, wherein each of the M radiation detectors comprises a two-dimensional array of sensing elements, and Wherein, the calibration plate includes N calibration patterns; using the M radiation detectors to respectively capture M calibration pattern images of the N calibration patterns based on the interaction between the first radiation beam and the N calibration patterns of the calibration plate, wherein the N calibration patterns of the calibration plate are at least (A) a first pattern type and (B) a second pattern type; and A relative position and orientation of each of the M radiation detectors is determined using a controller based on the image of the M images captured by each of the M radiation detectors.

14. The method according to claim 13, in, The N calibration patterns of the calibration plate are arranged into K strips, and the K strips are respectively parallel to and corresponding to the K rows of radiation detectors. Each of the K stripes includes P rows and multiple columns of calibration patterns, and In each of the M images, at least one array consisting of calibration patterns of P rows and Q columns located in a stripe of the K stripes among the N calibration patterns is captured.

15. The method of claim 14, wherein: Any array consisting of P rows and Q columns of calibration patterns among the N calibration patterns located in any stripe of the K stripes is unique in terms of the arrangement of the first type of calibration patterns and the second type of calibration patterns in any array, where P and Q are positive integers.

16. The method of claim 15, wherein: P=Q=3.

17. The method of claim 13, wherein: The N calibration patterns of the calibration plate are respectively N circular holes of two different sizes on the calibration plate corresponding to the first pattern type and the second pattern type.

18. The method of claim 13, wherein: K>1。 19. The method of claim 13, in, The first radiation source includes a sample stage for fixing a sample, and Wherein, sending the first radiation beam includes using a second radiation source to send a second radiation beam from the second radiation source to the sample, so that the sample sends the first radiation beam.

20. The method of claim 19, wherein: The first radiation beam and the second radiation beam are X-ray beams.

21. The method of claim 13, further comprising: After performing said capturing of said M images, said calibration plate is positioned in a second position such that said calibration plate does not block a path of a third radiation beam travelling from said first radiation source to said M radiation detectors of said image sensor.

22. The method of claim 21, wherein: Positioning the calibration plate includes rotating the calibration plate from the first position to the second position.

23. The method of claim 22, wherein: The calibration plate is rotated about an axis of rotation that intersects the first radiation source.

24. The method of claim 13, wherein: The calibration plate has a shape of a curved surface of a cylinder, and an axis of the cylinder intersects the first radiation source.

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