1. A method to account for cross-talk among a plurality of coherent scatter detectors of a multi-detector inverse fan beam x-ray diffraction imaging (MD-IFB XDI) system, said method comprising:
emitting a plurality of primary beams simultaneously from an x-ray source, each primary beam of the plurality of primary beams is directed to a corresponding convergence point associated with a corresponding coherent scatter detector of the plurality of coherent scatter detectors, each primary beam is configured to interact with an object to produce a scatter radiation;
measuring a diffraction profile Xk at each coherent scatter detector Dk of the plurality of coherent scatter detectors, each diffraction profile Xk comprises a spectrum of a number of photons from the scatter radiation measured by the coherent scatter detector Dk, wherein each diffraction Xk includes a cross-talk component arising from at least the primary beam directed to the convergence point associated with at least a second of the plurality of coherent scatter detectors Dj;
generating, for each of a plurality of energy levels within the spectrum measured in the diffraction profile Xk, a correction factor for the cross-talk component based on the energy level and a scatter angle defined between the primary beam directed to the convergence point associated with the coherent scatter detector Dj and a scatter radiation path from that primary beam to the coherent scatter detector Dk; and
correcting each diffraction profile Xk corresponding to each coherent scatter detector Dk to remove the cross-talk component.
2. A method in accordance with claim 1, further comprising calculating a plurality of scatter angles by which scatter beams arising from primary beams directed to convergence points for the remaining coherent scatter detectors reaches each coherent scatter detector Dk.
3. A method in accordance with claim 1, further comprising assuming that above a highest energy value, Etop, of the spectrum measured in the diffraction profile Xk corresponding to a highest momentum transfer value, xtop, the cross-talk component is zero.
4. A method in accordance with claim 3, comprising wherein said generating a correction factor comprises using a momentum transfer xk, wherein:
x
k
=
E
k
hc
\xb7
sin
\u2061
(
\u03b8
2
)
wherein Ek is the energy level, h is Planck’s constant, c is the speed of light and \u03b8 is the scatter angle defined between the primary beam directed to the convergence point associated with the coherent scatter detector Dj and a scatter radiation path from that primary beam to the coherent scatter detector Dk.
5. A method in accordance with claim 3, wherein said generating a correction factor for each of a plurality of energy levels comprises starting at the energy level designated by Etop and successively decrementing the energy level to a next energy level, thereby generating a correction factor at each of the plurality of energy levels for each coherent scatter detector Dk using post-correction data from a higher energy level.
6. A method in accordance with claim 5, further comprising:
setting the correction factor to zero if the momentum transfer xk is greater than or equal to xtop; and
setting the correction factor to the value of the diffraction profile measured at the coherent scatter detector Dj evaluated at the momentum transfer value xk if the momentum transfer xk is less than or equal to xtop.
7. A method in accordance with claim 6, wherein said correcting each diffraction profile Xk comprises subtracting the correction factor from the value of the diffraction profile Xk evaluated at the momentum transfer value xk.
8. A method in accordance with claim 5, further comprising terminating the correction procedure when the energy level is decremented below a threshold value.
9. A method in accordance with claim 3, wherein
the x-ray source comprises a multi-focus x-ray source (MFXS) configured to emit radiation sequentially from a plurality of focus points denoted by F1, F2, . . . Fn with a running index i, said method further comprising:
activating each focus point Fi in a sequence, each activated focus point Fi emits the plurality of primary beams; and
measuring a diffraction profile Xk at each coherent scatter detector Dk of the plurality of coherent scatter detectors while each focus point Fi is activated, wherein said generating a correction factor for each of a plurality of energy levels further comprises looping through of the plurality of focus points.
10. A method in accordance with claim 3, further comprising:
initializing the correction factor to zero at the momentum transfer value, xtop, corresponding to the highest energy value, Etop, of the spectrum measured in the diffraction Profile Xk.
11. A method in accordance with claim 1, said at least second coherent scatter detector Dj comprises multiple coherent scatter detectors Dj with a running index and said generating a correction factor for each of a plurality of energy levels further comprises looping through each scatter detector Dj for each energy level.
12. A method in accordance with claim 1, wherein
said generating a correction factor further comprises the use of a weighting factor defined for the scatter radiation path from the primary beam directed to the convergence point associated with the coherent scatter detector Dj to the coherent scatter detector Dk.
13. A method in accordance with claim 12, wherein the weighting factor
accounts for at least one of (i) a reduction in solid angle that the coherent scatter detector Dk presents to the scatter radiation path and (ii) an increased attenuation associated with the scatter path.
14. A security detection system, comprising:
an x-ray source configured to emit radiation;
a multi-angle primary collimator configured to select from the radiation emitted a plurality of primary beams each directed to a corresponding convergence point of a plurality of convergence points, each primary beam is configured to interact with an object to produce a scatter radiation;
a plurality of coherent scatter detectors each associated with a corresponding one of the plurality of convergence points and each configured to measure a number and an energy of photons from the scatter radiation; and
a processor coupled in electrical communication with each said coherent scatter detector of the plurality of coherent scatter detectors, said processor configured to:
record a diffraction profile Xk at each said coherent scatter detector Dk of said plurality of coherent scatter detectors, each diffraction profile Xk comprises a spectrum of the number of photons from the scatter radiation measured by said coherent scatter detector Dk, wherein each diffraction profile Xk includes a cross-talk component arising from at least the primary beam directed to the convergence point associated with at least a second of said plurality of coherent scatter detectors Dj;
generate, for each of a plurality of energy levels within the spectrum measured in the diffraction profile Xk, a correction factor for the cross-talk component based on the energy level and a scatter angle defined between the primary beam directed to the convergence point associated with said coherent scatter detector Dj and a scatter radiation path from that primary beam to said coherent scatter detector Dk; and
correct each diffraction profile Xk corresponding to each coherent scatter detector Dk to remove the cross-talk component.
15. A security detection system in accordance with claim 14, wherein said x-ray source comprises a multi-focus x-ray source (MFXS) configured to emit radiation sequentially from a plurality of focus points denoted by F1, F2, . . . Fn with a running index i, and said processor is further configured to:
activate each said focus point Fi in a sequence, wherein said multi-angle primary collimator is configured to select from the radiation emitted the plurality of primary beams from said activated focus and
record a diffraction profile Xk at each said coherent scatter detector Dk of said plurality of coherent scatter detectors while each said focus point Fi is activated; and
loop through each diffraction profile Xk for each of the plurality of focus points when generating a correction factor for each of the plurality of energy levels.
16. A security detection system in accordance with claim 15, wherein said at least second coherent scatter detector Dj comprises multiple coherent scatter detectors Dj with a running index j, and said processor is further configured to loop through each scatter detector Dj for each energy level.
17. A security detection system in accordance with claim 14, wherein said processor is further configured to assume that above a highest energy value Etop of the spectrum measured in the diffraction profile Xk corresponding to a highest momentum transfer value xtop the cross-talk component is zero.
18. A security detection system in accordance with claim 17, wherein the correction factor is generated using a momentum transfer xk, wherein:
x
k
=
E
k
hc
\xb7
sin
\u2061
(
\u03b8
2
)
wherein Ek is the energy level, h is Planck’s constant, c is the speed of light and \u03b8 is the scatter angle defined between the primary beam directed to the convergence point associated with the coherent scatter detector Dj and a scatter radiation path from that primary beam to the coherent scatter detector Dk.
19. A security detection system in accordance with claim 18, wherein the correction factor for each of the plurality of energy levels is generated by starting at the energy level designated by Etop and successively decrementing the energy level to a next energy level, thereby generating a correction factor for each said coherent scatter detector Dk using post-correction data.
20. A security detection system in accordance with claim 19, wherein said processor is further configured to:
set the correction factor to zero if the momentum transfer xk is greater than or equal to xtop; and
set the correction factor to the value of the diffraction profile measured at said coherent scatter detector Dj evaluated at the momentum transfer value xk if the momentum transfer xk is less than or equal to xtop.
21. A security detection system in accordance with claim 19, wherein said processor is further configured to terminate the correction procedure when the energy level is decremented below a threshold energy level value.
22. A security detection system in accordance with claim 18, wherein said processor is further configured to correct each diffraction profile Xk by subtracting the correction factor from the value of the diffraction profile Xk evaluated at the momentum transfer value xk.
23. A security detection system in accordance with claim 14, wherein said processor is further configured to use a weighting factor in generating the correction factor, wherein the weighting factor is defined for the scatter radiation path from the primary beam directed to the convergence point associated with said coherent scatter detector Dj to said coherent scatter detector Dk.
24. A security detection system in accordance with claim 23, wherein the weighting factor accounts for at least one of (i) a reduction in solid angle that said coherent scatter detector Dk presents to the scatter radiation path and (ii) an increased attenuation associated with the scatter path.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A radial bearing, comprising: a bearing body, which includes a receiving space for a shaft to be arranged therein,
wherein the bearing body has an inner wall facing the receiving space, the inner wall including a plurality of transverse grooves running in an axial direction and separated from one another in a circumferential direction by a plurality of separating portions, and
a supply channel penetrating the bearing body provided in at least one separating portion of the plurality of separating portions, the at least one separating portion having at least one oil pocket spaced from the supply channel.
2. The radial bearing according to claim 1, wherein the at least one oil pocket is arranged offset from the supply channel at least one of in the axial direction and in the circumferential direction.
3. The radial bearing according to claim 2, wherein the at least one oil pocket is arranged offset from the supply channel of the at least one separating portion in a direction of rotation of the shaft relative to the circumferential direction.
4. The radial bearing according to claim 2, wherein the at least one separating portion includes two oil pockets arranged offset from the supply channel at least one of in the axial direction and in the circumferential direction.
5. The radial bearing according to claim 1, wherein the at least one oil pocket is arranged offset from the supply channel in a direction of rotation of the shaft in the circumferential direction.
6. The radial bearing according to claim 5, wherein the at least one oil pocket includes a pocket depth running along a radial direction, wherein the pocket depth follows at least one of an even and rising course along at least one of a longitudinal section running in the circumferential direction and a transverse section running in the axial direction.
7. The radial bearing according to claim 6, wherein the pocket depth of the at least one oil pocket includes at least one step.
8. The radial bearing according to claim 5, wherein the at least one separating portion includes the supply channel and at least two oil pockets arranged offset from the supply channel in the direction of rotation.
9. The radial bearing according to claim 8, wherein the at least two oil pockets include equal axial spacing from the supply channel.
10. The radial bearing according to claim 1, wherein the at least one oil pocket is formed at least in regions on at least one transverse groove.
11. The radial bearing according to claim 1, wherein the at least one separating portion includes the supply channel and at least two oil pockets.
12. The radial bearing according to claim 11, wherein the at least two oil pockets have a same axial spacing from the supply channel.
13. The radial bearing according to claim 1, wherein the at least one oil pocket has a pocket depth running along a radial direction, wherein the pocket depth of the at least one oil pocket follows at least one of an even and rising course at least one of along a longitudinal section running in the circumferential direction and along a transverse section running in the axial direction.
14. The radial bearing according to claim 13, wherein the pocket depth of the at least one oil pocket follows a stepped course.
15. The radial bearing according to claim 1, wherein the at least one separating portion includes at least two oil pockets which are arranged adjacent in the circumferential direction.
16. The radial bearing according to claim 1, wherein the at least one oil pocket is formed at least one of quadrangular, triangular and curved.
17. The radial bearing according to claim 1, wherein the bearing body is produced by processing a flat work piece, which is subsequently formed.
18. The radial bearing according to claim 1, wherein the bearing body is formed annular groove-free.
19. The radial bearing according to claim 1, wherein the at least one oil pocket includes a pocket depth running along a radial direction, wherein the pocket depth includes at least one step.
20. A radial bearing, comprising:
a bearing body having a receiving space for a shaft, the bearing body including an inner wall facing the receiving space, the inner wall including a plurality of transverse grooves running in an axial direction and separated from one another in a circumferential direction via separating portions; and
a supply channel penetrating the bearing body disposed in at least one separating portion, wherein the at least one separating portion includes two oil pockets spaced from the supply channel;
wherein the respective oil pockets include a pocket depth running along a radial direction, the pocket depth of the respective oil pocket following at least one of an even and rising course along at least one of a longitudinal section running in the circumferential direction and a transverse section running in the axial direction, wherein at least one pocket depth includes a step.