Apparatus and method for detecting gamma ray radiation

Abstract

An apparatus for detecting gamma ray (GR) radiation having a plurality of detector cells arranged in an array is disclosed. Each cell includes a housing having an aperture, the housing comprising a GR absorbing material, and a GR detector disposed within the housing such that external gamma rays are received at the GR detector via the aperture. The apertures of each cell are aligned.

1 . An apparatus for detecting gamma ray (GR) radiation, comprising:
 a plurality of detector cells arranged in an array, each cell comprising:   a housing having an aperture, the housing comprising a GR absorbing material; and   a GR detector disposed within the housing such that external gamma rays are received at the GR detector via the aperture;   wherein the apertures of each cell are aligned.   
   
   
       2 . The apparatus of  claim 1 , wherein:
 the GR detector comprises a detector crystal and a light detection device, the detector crystal disposed proximate the aperture for receiving the gamma rays.   
   
   
       3 . The apparatus of  claim 2 , wherein:
 the photo-multiplier tube is disposed distant from the aperture.   
   
   
       4 . The apparatus of  claim 1 , wherein:
 the plurality of detector cells are arranged end-to-end in a repeat pattern.   
   
   
       5 . The apparatus of  claim 1 , wherein:
 the GR absorbing material comprises Lead or Tungsten.   
   
   
       6 . The apparatus of  claim 1 , wherein:
 the plurality of detector cells is five detector cells.   
   
   
       7 . The apparatus of  claim 1 , wherein:
 the housing is configured to provide both vertical and azimuthal shielding of gamma rays while allowing absorption of gamma rays via the aperture.   
   
   
       8 . The apparatus of  claim 1 , further comprising:
 a radiation source capable of producing a radiation region of influence;   wherein the entire array or part thereof of detector cells is disposed within the region of influence.   
   
   
       9 . The apparatus of  claim 8 , wherein:
 the radiation source comprises a pulse neutron generator, a gamma ray generator, a radioactive material, or any combination comprising at least one of the foregoing.   
   
   
       10 . The apparatus of  claim 1 , wherein:
 the apertures of each cell are aligned with a defined spacing for high resolution GR detection.   
   
   
       11 . The apparatus of  claim 1 , wherein:
 each cell comprises two opposing apertures.   
   
   
       12 . A method for evaluating a characteristic of a region, comprising:
 disposing proximate the region an apparatus for detecting gamma ray (GR) radiation, the apparatus comprising a plurality of detector cells arranged in an array, each cell comprising a housing having an aperture, the housing comprising a GR absorbing material, and a GR detector disposed within the housing such that external gamma rays are received at the GR detector via the aperture, wherein the apertures of each cell are aligned with a defined spacing for high resolution GR detection;   receiving gamma rays at the apparatus via the plurality of apertures; and   analyzing the received gamma rays to provide high resolution measurement of the characteristic of the region.   
   
   
       13 . The method of  claim 12 , wherein:
 the high resolution measurement comprises a high resolution formation parameter measurement.   
   
   
       14 . The method of  claim 12 , wherein:
 the analyzing enables detecting the presence of laminations within the region.   
   
   
       15 . The method of  claim 12 , further comprising:
 subjecting the region to radiation capable of producing a radiation region of influence, the entire array of detector cells being disposed within the region of influence;   wherein the receiving gamma rays comprises receiving inelastic gamma rays generated by neutron collisions arising from the subjecting the region to radiation.   
   
   
       16 . The method of  claim 15 , wherein:
 the subjecting the region to radiation comprises subjecting the region to radiation via the apparatus comprising a radiation source.   
   
   
       17 . The method of  claim 16 , wherein:
 the radiation source comprises a pulse neutron generator, a gamma ray generator, a radioactive material, or any combination comprising at least one of the foregoing.   
   
   
       18 . The method of  claim 12 , wherein each detector cell of the apparatus comprises two opposing apertures, the method further comprising:
 rotating the array of detector cells relative to a stratigraphic bed;   receiving double count rates of gamma rays arising from each of the two opposing apertures; and   analyzing the received gamma rays to determine the strike azimuth of the stratigraphic bed.