Patent ID: 7634059

Claim:
A downhole tool for use in a borehole or well, comprising: a) a housing having a longitudinal axis; b) an X-ray source located in said housing, said X-ray source including an X-ray tube which generates X-rays capable of exiting said housing; c) a photon detector located in said housing and axially displaced from said X-ray source relative to said longitudinal axis, said photon detector comprising a microchannel plate and an anode coupled to said microchannel plate; d) shielding between said X-ray source and said photon detector, said shielding substantially blocking X-rays from directly reaching said detector from said X-ray source, said shielding defining a cavity for said photon detector and conical chamber adjacent said cavity, said conical chamber terminating in a radially directed pinhole through which X-rays generated by said X-ray source and scattered outside of said housing can reach said photon detector, said conical chamber and said pinhole configured to function as a camera obscura; and e) means for rotating said housing so as to cause said radially directed pinhole to face different azimuthal directions.