Method and apparatus for the detection and imaging of heavy metals

Claim 2

An automatic method of detaching in sequentially inspected objects a target article made of or containing an elemental or compounded target metal of the kind capable of producing with impinging X-ray radiation within the range of 60-160 KeV a detachable photoelectric interaction, said method comprising the steps of providing a radiation generating assembly comprising a 110-160 KeV X-ray source in association with collimating and filtering means, which filtering means are designed to successively generate several energy bins during each one of repeating cycles; generating with such assembly a collimated X-ray beam consisting of repeating cycles each comprising several energy bins centered around the K-energy of said target meal; placing at a distance from said radiation generating assembly and in the region flushed by said collimated X-ray beam a linear array of slid state, spectroscopy grade detectors in association with signal counting, processing and imaging means; providing object carrier means intermediary between said radiation generating assembly and linear array of solid state, spectroscopy grade detectors; placing objects on said object carrier means; arranging for said energy generating assembly on the one hand and said object carrier means on the other hand to be displaced relative to each other at a relative velocity so adjusted that during each one of predetermined pixels commensurate with the expected smallest size of said target article the full energy range of one of said repeating cycles impinges a full cross-section of an inspected object without any mutual dislocation of said radiation generating assembly and linear array of solid state detectors; whereby successive electrical signals are produced in said linear array of spectroscopy grade detectors; using said electrical signals for recording for each pixel the intensity of transmitted radiation of selected energy bands; determining for each pixel the ratios between the transmitted radiation in said selected energy bands; and processing the resulting data to produce an image of any detected target article.

Claim 3

The method of claim 1, wherein the relative displacement between the radiation generating assembly and the object carrier means is brought about by moving the object carrier means.

Claim 4

The method of claim 1, wherein the relative displacement between the radiation generating assembly and the object carrier means is brought about by moving synchronically the radiation generating assembly and linear array of solid stat detectors.

Claim 5

The method of claim 1, wherein the relative displacement between the object carrier means and the radiation generating assembly is continuous.

Claim 6

The method of claim 1, wherein the relative displacement between the object carrier means and the radiation generating assembly is intermittent.

Claim 7

An automatic method of detecting in sequentially inspected objects a target article made of or containing an elemental or compounded target metal of the kind capable of producing with impinging X-radiation within the range of 60-160 KeV a detectable photoelectric interaction, said method comprising the steps of providing a radiation generating assembly comprising a 110-160 KeV X-ray source in association with collimating and filtering means, which filtering means are designed to generate during each of said cycles one single, energy bin; generating with such assembly a collimated X-ray beam consisting of repeating cycles each comprising one single energy bin having a flux centered around the K-edge energy of said target metal; placing at a distance from the radiation generating assembly and in a region flushed by said collimated X-ray beam a linear array of solid state, spectroscopy grade detector in association with signal counting, processing and imaging means, which detectors are arranged in such a way as to differentiate between simultaneous different radiation flux attenuations within predetermined energy ranges of said single energy bin; providing object carrier means intermediary between said radiation generating assembly and linear array of solid state, spectroscopy grade detectors; placing objects on said object carrier means; arranging for said radiation generating assembly on the one hand and said object carrier means on the other hand to be displaced relative to each other at a relative velocity so adjusted that during each one of predetermined pixels commensurate with the expected smallest size of said target article, the full energy range of one of said repeating cycles impinges a full cross-section of an inspected object without any mutual dislocation between said radiation generating assembly and linear array of solid state detectors, whereby successive electrical signals are produced in said linear array of spectroscopy grade detectors; using said electrical signals for recording for each pixel the intensity of transmitted radiation of selected energy bands; determining for each pixel the ratios between the transmitted radiation in said selected energy bands; and processing the resulting data to produce an image of any detected target article.

Claim 8

An automatic method of detecting in sequentially inspected objects a target article made of or containing an elemental or compounded target metal of the kind capable of producing with impinging X-radiation within the range of 60-160 KeV a detectable photoelectric interaction, said method comprising the steps of providing a radiation generating assembly comprising a 110-160 KeV X-ray source in association with collimating and filtering means, which filtering means are designed to generate during each of said cycles one single, energy bin; generating with such assembly a collimated X-ray beam consisting of repeating cycles each comprising one single energy bin having a flux centered around the K-edge energy of said target metal; placing at a distance from the radiation generating assembly and in a region flushed by said collimated X-ray beam a linear array of solid state, spectroscopy grade detector in association with signal counting, processing and imaging means, which detectors are arranged in such a way as to differentiate between simultaneous different radiation flux attenuations within predetermined energy ranges of said single energy bin; providing object carrier means intermediary between said radiation generating assembly and linear array of solid state, spectroscopy grade detectors; placing objects on said object carrier means; arranging for said radiation generating assembly on the one hand and said object carrier means on the other hand to be displaced relative to each other at a relative velocity so adjusted that during each one of predetermined pixels commensurate with the expected smallest size of said target article, the full energy range of one of said repeating cycles impinges a full cross-section of an inspected object without any mutual dislocation between said radiation generating assembly and linear array of solid state detectors, whereby successive electrical signals are produced in said linear array of spectroscopy grade detectors; using said electrical signals for recording for each pixel the intensity of transmitted radiation of selected energy bands; determining for each pixel the ratios between the transmitted radiation in said selected energy bands; and processing the resulting data to produce an image of any detected target article.

Claim 9

The method of claim 6, wherein the relative displacement between the radiation generating assembly and the object carrier means is brought about by moving the object carrier means.

Claim 10

The method of claim 6, wherein the relative displacement between the radiation generating assembly and the object carrier means is brought about by moving synchronically and radiation generating assembly and linear array of solid state detectors.

Claim 11

The method of claim 6, wherein the relative displacement between the object carrier means and the radiation generating assembly is continuous.

Claim 12

The method of claim 6, wherein the relative displacement between the object carrier means and the radiation generating assembly is intermittent.

Claim 15

The apparatus of claim 11, wherein said object carrier means is a conveyor belt.

Claim 16

The apparatus of claim 11, comprising means for synchronically, continuously or intermittently moving the radiation generating means and linear array of solid state, spectroscopy grade detectors.

Claim 19

The apparatus of claim 14, wherein said object carrier means is a conveyor belt.

Claim 20

The apparatus of claim 14, comprising means for synchronically, continuously or intermittently moving the radiation generating means and linear array of solid state, spectroscopy grade detectors.