Patent ID: 8000440

Claim:
A target composition determination apparatus comprising, an x-ray emission element configured to concurrently transmit x-ray photons with a plurality of different energy levels spanning the x-ray spectrum at a target; an x-ray detection element configured to receive x-ray photons which have interacted with the target and to determine the energy levels of each of said received x-rays, said x-ray detection element being configured to generate at least one output signal indicative of the number of x-rays which have interacted with the target and the energy levels determined for each of said x-rays, wherein the output signal or signals of the x-ray detection element are batched over a pre-selected time period to define the physical resolution of the target composition apparatus when the target is moved relative to the apparatus; and a processing element configured to: receive said output signal or signals; select output signal or signals having energy levels of greatest significance; apply at least one multivariate calibration prepared for a particular class of targets to data relating to the number of x-rays which have interacted with the target and the energy levels determined for each of said x-rays as derived from the selected signal or signals, to determine the presence of at least one component material within the target, wherein the multivariate calibration correlates the data, its variances and co-variances against one or more of: previously identified material levels, the presence of an unknown material, or the presence of an undesirable material; and indicate the presence of at least one component material within the target.