Patent ID: 6528795
Filing Date: 2003-03-04
Classification: G01T

Abstract:
A device for determining the photon energy E1 and direction cone angle of incident gamma ray with two Compton scattering interactions and one subsequent interaction, comprising:a first radiation detector for receiving an incident gamma ray having an unknown photon energy E1 and an unknown direction, for scattering a photon energy E2 in a first Compton scattering interaction at a first scatter angle &thgr;1, and for providing a first output corresponding to the first Compton scattering interaction; a second radiation detector for receiving photon energy E2 and scattering some photon energy E3 in a second Compton scattering interaction at a second scatter angle &thgr;2, and for providing a second output corresponding to the second Compton scattering interaction; a third radiation detector for receiving photon energy E3, and interacting with photon energy E3 in a third interaction, and for providing a third output corresponding to the third interaction; and a processor for receiving and processing said first, second, and third outputs and for calculating said photon energy E1 and direction cone angle of said incident gamma ray based on said outputs, said first and second radiation detectors being sensitive to the position and energy of incident gamma ray and said third radiation detector being sensitive to at least the position of incident gamma ray, and wherein said calculating of said photon energy E1 and direction cone angle of said incident gamma ray does not require absorption and measurement of the entire or substantially all the energy E1 in said device.