Patent ID: 6518579
Filing Date: 2003-02-11
Classification: G01T

Abstract:
An apparatus for a non-destructive determination of an unknown depth of a radiological contamination having a depth distribution in a building medium, the building medium having a known attenuation coefficient, the radiological contamination being of a type which emits gamma radiation with at least two gamma rays of different energies per disintegration or a single gamma ray with at least one gamma-emitting progeny of different energies, but at an unknown rate, the apparatus comprising:collimator means for collimating the gamma radiation emitted from the contamination and at the surface of the medium; detector means having a gamma ray counting surface associated with the collimator means for simultaneously counting the collimated gamma radiation including the two gamma rays of different energies from the collimator means; computing means operatively connected to the detector means for applying a gamma penetration depth unfolding algorithm to the two gamma rays simultaneously counted using a data differentiation technique with a point kernel implementation to iterate the depth of the contamination; and a computer connected to the detector means and containing the computing means as a computer program.