Detection of Ionising Radiation

Abstract

A detector for detecting ionising radiation comprises a scintillator 10 selected to emit light in response to incidence thereon of radiation to be detected, at least one detector 16 for detecting said emitted light, and at least one optical waveguide 12 for transmitting said emitted light to said detector 16 . The optical waveguide typically comprises a flexible solid or hollow fibre that can be incorporated into a flexible mat or into a fibre-reinforced structure, so that the detector is integrated therewith.

1 . A detector for detecting ionising radiation, said detector comprising:
 a scintillator selected to emit light in response to incidence thereon of radiation to be detected;   at least one detector for detecting said emitted light, and   at least one optical waveguide for transmitting said emitted light to said detector.   
   
   
       2 . A detector according to  claim 1 , wherein said waveguide is an optical fibre and said scintillator is a solid scintillator element through which said optical fibre passes, whereby light emissions in said scintillator element are transmitted to said detector by said fibre. 
   
   
       3 . A detector according to  claim 1  or  claim 2 , wherein the refractive index of the scintillator element is less than that of the optical fibre. 
   
   
       4 . A detector according to  claim 2 , wherein at least part of the external surfaces of the scintillator element and the optical fibre are provided with a coating of reflective material. 
   
   
       5 . A detector according to  claim 4 , wherein said reflector material is selected from the group consisting of gold, silver, platinum, indium and aluminium. 
   
   
       6 . A detector according to  claim 2 , which includes a plurality of optical fibres passing through said scintillator elements and in optical contact therewith, and means for detecting said light emissions. 
   
   
       7 . A detector according to  claim 6 , wherein said optical fibres are disposed orthogonally in rows and columns. 
   
   
       8 . A detector according to  claim 6 , wherein said optical fibres are disposed orthogonally in three dimensions (X,Y,Z). 
   
   
       9 . A detector according to  claim 7 , wherein said optical fibres are arranged in stacked planes of rows and columns. 
   
   
       10 . A detector according to any of  claims 2 , wherein said optical fibre follows a helical or serpentine path through said scintillator elements. 
   
   
       11 . A detector according to any of  claims 2 , wherein said optical fibre is provided as a woven fabric element. 
   
   
       12 . A detector according to  claim 2 , wherein said scintillator element is of spherical shape, with said optical fibre wrapped into a ball configuration. 
   
   
       13 . A detector according to  claim 1 , wherein said at least one waveguide comprises a hollow optical fibre containing a scintillator material. 
   
   
       14 . A detector according to  claim 13 , wherein said scintillator material comprises a liquid, gel or solid. 
   
   
       15 . A detector according to  claim 14 , wherein said scintillator material is a liquid or gel, and including means for selectively introducing and withdrawing said scintillator material from said hollow fibre. 
   
   
       16 . A detector according to  claim 13 , wherein the light emissions are transmitted to said detector down the central space of a tube by total internal reflection off inner walls of said fibre. 
   
   
       17 . A detector according to  claim 16 , wherein at least part of the inner surface of the fibre is provided with a coating of reflective material. 
   
   
       18 . A detector according to any of  claim 13 , wherein the light emissions are transmitted to said detector through the fibre wall by total internal reflection within the fibre wall. 
   
   
       19 . A detector according to  claim 18 , wherein at least part of the external surface of the fibre is provided with a coating of reflective material. 
   
   
       20 . A detector according to  claim 17 , wherein the reflective material is selected from the group gold, silver, platinum, indium and aluminium. 
   
   
       21 . A detector according to  claim 13 , which includes a plurality of optical fibres passing through said scintillator elements and in optical contact therewith, and means for detecting said light emissions. 
   
   
       22 . A detector according to  claim 21 , wherein said optical fibres are disposed orthogonally in rows and columns. 
   
   
       23  A detector according to  claim 21 , wherein said optical fibres are disposed orthogonally in three dimensions (X,Y,Z). 
   
   
       24 . A detector according to  claim 21 , wherein said optical fibres are arranged in stacked planes of rows and columns. 
   
   
       25 . A detector according to  claim 13 , wherein said optical fibre follows a helical or serpentine path through said scintillator elements. 
   
   
       26 . A detector according to  claim 13 , wherein said optical fibre is provided as a woven fabric element. 
   
   
       27 . A detector according to  claim 13 , wherein said scintillator element is of spherical shape, with said optical fibre wrapped into a ball configuration. 
   
   
       28 . A detector according to  claim 1 , including means for detecting light emissions at opposite ends of said waveguide and means responsive to the timings of the light emissions to determine the location of the incident radiation along the length of the waveguide. 
   
   
       29 . A detector according to  claim 28 , including means for detecting the location of the incident radiation in two dimensions. 
   
   
       30 . A detector according to  claim 1 , including a moderator material to moderate the radiation incident on said scintillator material. 
   
   
       31 . A detector according to  claim 30 , wherein the moderator material is contained in a hollow fibre adjacent the scintillator material. 
   
   
       32 . A detector according to  claim 1 , wherein said scintillator material is responsive to at least one of alpha particles, beta particles (electrons), x-ray radiation, gamma radiation, neutrons, protons. 
   
   
       33 . A detector according to  claim 1 , including a plurality of respective scintillators or groups thereof and a plurality of associated waveguides, with each scintillator or group thereof being responsive to a selected radiation. 
   
   
       34 . A detector according to  claim 33 , wherein said scintillators or groups thereof are arranged in layers, with each layer being responsive to a predetermined radiation. 
   
   
       35 . A detector according to  claim 1 , including means for injecting light into the optical waveguide, and means for detecting and processing of the detected light signal to determine a condition of the optical fibre. 
   
   
       36 . A fibre composite structure including a matrix material, a plurality of structural fibres, and at least one optical waveguide embedded therein, with a scintillator in optical contact with said waveguide and selected to emit light in response to ionising radiation, and a detector for detecting light emissions transmitted from said scintillator by said waveguide. 
   
   
       37 . A fibre composite structure according to  claim 36 , which includes a plurality of scintillators and a plurality of optical waveguides embedded in said matrix. 
   
   
       38 . A flexible textile material comprising textile fibres and incorporating therein at least one optical waveguide, with a scintillator in optical contact with said waveguide and selected to emit light in response to ionising radiation, and a detector for detecting light emissions transmitted by said waveguide. 
   
   
       39 . A method of detecting and locating of the incidence of radiation along an elongate path or structure which comprises providing at least one elongate optical waveguide having disposed therealong at least one scintillator element, and a detector for detecting light emissions transmitted by said waveguide from said scintillator element or elements. 
   
   
       40 . A method of detecting and locating emission of radiation from a space which comprises surrounding at least part of said space with a plurality of fibres each having scintillator elements associated therewith and detecting emission of light from said scintillator elements at the ends of said fibres. 
   
   
       41 . A combination comprising a detector as claimed in  claim 1  combination with a radiation shield means, wherein the detector is operable to monitor and/or control the effectiveness of the radiation shield means. 
   
   
       42 . A combination according to  claim 41  wherein the shield means is adapted to allow the radiation shielding characteristics thereof to be adjusted. 
   
   
       43 . A combination according to  claim 42 , further comprising a processor responsive to the output of said detector to control the radiation shielding characteristics of the shield to at least reduce the transmission of radiation therethrough.