Patent ID: 8884234

Claim:
An apparatus for determining a direction of travel of a neutron emitted from a source, the apparatus comprising: a chamber containing (i) nuclei that recoil upon interaction with an incoming neutron along a path direction of travel of the incoming neutron from a source of the neutron to the chamber and (ii) atoms capable of being ionized by the recoiled nuclei thereby releasing electrons; an electron-interaction material disposed at the chamber and configured to receive electrons released by the ionized atoms and to emit photons upon the interaction with the received electrons along the path direction; an imager configured to form an image of photons emitted by the electron-interaction material, wherein the image comprises the path direction of travel of the incoming neutron; an orientation sensor configured to sense an azimuthal orientation direction of the imager in order to relate the path direction of travel of the incoming neutron to the azimuthal orientation direction of the imager; and a processor configured to receive the image and the azimuthal orientation direction of the imager and to determine the direction of travel of the neutron emitted from the source using the path direction in the image directly and the azimuthal orientation direction.