APPARATUS AND METHOD FOR RADIATION DETECTION
Embodiments of the invention provide a radiation detector, comprising a convertor comprising an inorganic scintillator for absorbing incident neutrons and outputting photons, a light collecting body arranged in relation to a wavelength shifting fibre for receiving photons from the convertor and directing the photons to the wavelength shifting fibre, and one or more photo-detectors arranged to receive photons from the wavelength shifting fibre and output electrical signals in response thereto.
1 . A radiation detector, comprising:
a convertor comprising an inorganic scintillator for absorbing incident neutrons and outputting photons;
a light collecting body arranged in relation to a wavelength shifting fibre for receiving photons from the convertor and directing the photons to the wavelength shifting fibre; and
one or more photo-detectors arranged to receive photons from the wavelength shifting fibre and output electrical signals in response thereto.
2 . The radiation detector of claim 1 , comprising a light reflecting layer arranged around the body to inwardly reflect photons toward the wavelength shifting fibre.
3 . The radiation detector of claim 1 , wherein the wavelength shifting fibre is arranged in a channel through the body.
4 . The radiation detector of claim 3 , wherein the wavelength shifting fibre is arranged in the channel such that a gap exists between an outer periphery of the fibre and an interior surface of the channel.
5 . The radiation detector of claim 1 , wherein the inorganic scintillator is zinc sulphide.
6 . The radiation detector of claim 1 , comprising a first photo-detector arranged at a first end of the fibre and a second photo-detector arranged at a second end of the fibre.
7 . The radiation detector of claim 6 , comprising a control unit arranged to determine a position of the radiation detection based upon a relative timing of signals from the first and second photo-detectors.
8 . The radiation detector of claim 1 , wherein the body is arranged in relation to a plurality of wavelength shifting fibres arranged in non-parallel orientations.
9 . The radiation detector of claim 1 , wherein the body has an axial cross section shape selected from semi-circular, parabolic, triangular or rectangular.
10 . The radiation detector of claim 1 , wherein the convertor is a layer arranged upon a generally planar surface of the body.
11 . The radiation detector of claim 1 , comprising a second body arranged in relation to a second wavelength shifting fibre, wherein the bodies are interposed by the convertor layer.
12 . The radiation detector of claim 1 , wherein the body comprises a an organic scintillator.
13 . The radiation detector of claim 12 , wherein the plastic scintillator comprises POP and POPOP.
14 . The radiation detector of claim 12 , wherein the plastic scintillator is arranged for emitting photons in response to charged particles.
15 . The radiation detector of claim 12 , wherein the charged particles result from an inverse beta decay reaction; optionally the charged particles are positrons.
16 . The radiation detector of claim 14 , wherein the charged particles are muons.
17 . The radiation detector of claim 12 , wherein a control unit is arranged to determine radiation detection according to a temporal relationship of a prompt response and a delayed response.
18 . The radiation detector of claim 17 , wherein the control unit is arranged to determine the radiation detection according to the prompt response, the delayed response and a predetermined time threshold.
19 . A detector assembly comprising a plurality of radiation detectors according to claim 1 .
20 . The detector assembly of claim 19 , wherein the plurality of radiation detectors are arranged generally side-by-side.
21 . The detector assembly of claim 19 , wherein the plurality of radiation detectors are arranged in stacked relation.
22 . The detector assembly of claim 19 , when dependent upon claim 17 , wherein the control unit is arranged to determine the radiation detection, at least in part, upon a distance or/and direction between a detector outputting the prompt response and a detector outputting the delayed response.
23 . The detector assembly of claim 22 , wherein the control unit is arranged to determine an initial direction of travel of incident radiation based upon a location of detection of the prompt response and the delayed response.
24 . The detector assembly of claim 19 , when dependent upon claim 8 or any claim dependent thereon, wherein a control unit is arranged to determine a location of radiation detection based upon an output of a plurality of photo-detectors arranged responsive to non-parallel fibres.
25 . The detector assembly of claim 19 , comprising a moderator for moderating incident neutrons.
26 . The detector assembly of claim 25 , wherein the detectors are arranged along a major planar surface of the moderator.