Patent ID: 7157719

Claim:
An neutron imaging apparatus for obtaining an image of a general shape of a neutron emitting source and a bearing of said source relative to the neutron imaging apparatus, the neutrons having a momentum, the apparatus comprising: I. A chamber containing a gas, said gas having: (a) a high probability of interacting with low energy neutrons, and (b) releasing collision products that maintain said neutron momentum, and generate ionization particles in said gas; II. a first electrode in the chamber, designed to provide an electronic signal indicative of the geometric impact location of ionization particles on the electrode; III. an electric field in said chamber designed to drift the ionization particles to the first electrode; IV. a means to read out the electronic signal from the first electrode indicating the location of the impact of the ionization and a time of impact of the ionization on the first electrode; V. a memory for storing a plurality of readout electronic signals representing the location and time of impact of a plurality of charged particles; and VI. a computer adapted to receive said plurality of electronic signals and programmed: (a) to analyze said plurality of electronic signals and impact times of a plurality of charged particles on the first electrode and to provide three dimensional vectors indicative of the neutron path directions in three dimensional space; and (b) to indicate the location of said source of neutrons relative to the imaging apparatus position by applying back projection algorithms which extend the neutron tracks to their point of origin.