Automobile scanning system
First Claim
1. An apparatus for imaging an organic object contained within a metal enclosure, comprising:
- an x-ray source for producing an x-ray beam passing through said metal enclosure;
a first beam filter for creating a low-energy x-ray spectrum;
said first beam filter comprising an atomic element having a high k-edge energy;
a second beam filter for creating a high-energy x-ray spectrum;
a filter exchanger for alternately positioning said first beam filter and said second beam filter within said x-ray beam;
an x-ray detector for measuring an intensity of said x-ray beam exiting said metal enclosure;
a computer calculates a metal suppressed image from the x-ray beam intensity measurements using logarithmic subtraction;
whereby the image of said organic object is isolated from the interference of said metal enclosure.
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Accused Products
Abstract
A dual-energy x-ray imaging system searches a moving automobile for concealed objects. Dual energy operation is achieved by operating an x-ray source at a constant potential of 100 KV to 150 KV, and alternately switching between two beam filters. The first filter is an atomic element having a high k-edge energy, such as platinum, gold, mercury, thallium, lead, bismuth, and thorium, thereby providing a low-energy spectrum. The second filter provides a high-energy spectrum through beam hardening. The low and high energy beams passing through the automobile are received by an x-ray detector. These detected signals are processed by a digital computer to create a steel suppressed image through logarithmic subtraction. The intensity of the x-ray beam is adjusted as the reciprocal of the measured automobile speed, thereby achieving a consistent radiation level regardless of the automobile motion. Accordingly, this invention provides images of organic objects concealed within moving automobiles without the detritus effects of overlying steel and automobile movement.
138 Citations
21 Claims
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1. An apparatus for imaging an organic object contained within a metal enclosure, comprising:
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an x-ray source for producing an x-ray beam passing through said metal enclosure; a first beam filter for creating a low-energy x-ray spectrum;
said first beam filter comprising an atomic element having a high k-edge energy;a second beam filter for creating a high-energy x-ray spectrum; a filter exchanger for alternately positioning said first beam filter and said second beam filter within said x-ray beam; an x-ray detector for measuring an intensity of said x-ray beam exiting said metal enclosure; a computer calculates a metal suppressed image from the x-ray beam intensity measurements using logarithmic subtraction; whereby the image of said organic object is isolated from the interference of said metal enclosure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for searching an automobile for security threats, comprising:
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x-ray generating means for penetrating said automobile with x-ray radiation; switching filter means for changing said x-ray radiation between a low-energy spectrum and a high-energy spectrum, wherein said low-energy spectrum is substantially determined by the k-edge energy of a high atomic number element; x-ray detector means for converting the x-ray radiation that penetrates said automobile into a digitally represented signal; computer means for converting said digitally represented signal into a steel suppressed digital image of said automobile using logarithmic subtraction. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. An apparatus for searching an automobile for security threats, comprising:
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x-ray generating means for penetrating said automobile with x-ray radiation; switching filter means for changing said x-ray radiation between a low-energy spectrum and a high-energy spectrum, the switching filter means comprises rotating filter means, said rotating filter means comprising a low-energy filter material and a high-energy filter material, the low-energy filter material is selected from the group consisting of platinum, gold, mercury, thallium, lead, bismuth, and thorium; wherein said low-energy spectrum is substantially determined by the k-edge energy of a high atomic number element; x-ray detector means for converting the x-ray radiation that penetrates said automobile into a digitally represented signal; computer means for converting said digitally represented signal into a steel suppressed digital image of said automobile using logarithmic subtraction. - View Dependent Claims (19, 20, 21)
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Specification