Patent ID: 8247767

Claim:
A particle detection system, comprising: a first set of position sensitive charged particle detectors located on a first side of an object holding area to measure positions and directions of incident charged particles towards the object holding area; a second set of position sensitive charged particle detectors located on a second side of the object holding area opposite to the first side to measure positions and directions of outgoing charged particles exiting the object holding area; and a signal processing unit to receive data of measured signals of the incoming charged particles from the first set of position sensitive charged particle detectors and measured signals of the outgoing charged particles from the second set of position sensitive charged particle detectors, wherein the signal processing unit is configured to analyze scattering of the charged particles in the materials within the object holding area based on the measured incoming and outgoing positions and directions of charged particles to obtain a tomographic profile or the spatial distribution of scattering centers within the object holding area, wherein the signal processing unit is configured to reconstruct a trajectory of a charged particle through the object holding area, measure a momentum of an incoming charged particle based on signals from the first set of position sensitive charged particle detectors, measure a momentum of an outgoing charged particle based on signals from the second set of position sensitive charged particle detectors, and obtain a spatial distribution of a scattering density of the object holding area, and wherein the signal processing unit includes a mechanism to determine spatial distribution of the scattering density of the object holding area to obtain predetermined charged particle tomography data corresponding to scattering angles and estimated momentum of charged particles passing through the object holding area; to provide a probability distribution of charged particle scattering for use in an expectation maximization algorithm based on a statistical multiple scattering model; and to determine a substantially maximum likelihood estimate of the scattering density of the object holding area using the expectation maximization algorithm; wherein the first set of position sensitive charged particle detectors includes a first double-layer of drift tubes arranged in an X direction and a second double-layer of drift tubes arranged in a Y direction.