The present invention pertains to a non-rotating method for non-intrusively
determining the density of a point embedded within an object, without
necessarily obtaining a full image for the entire object. The method
consists of passing a X-ray beam through a point within an object and
measuring Compton scatterings from the point from a first and second
energy bands within the energy spectrum of the X-ray beam, along a first
and second angles from the X-ray beam. Using the kinetics of Compton
scattering at a specific angle, four equations are formulated with four
measurements and four unknowns; the radiation attenuation factor along the
object between the X-ray source and the point, the radiation attenuation
factor between the point and each of the detectors and the density of the
object at the point. The four equations are solved simultaneously to
determined the four unknowns. There is also provided a matrix inversion
process to facilitate the solution of the equations.