Radiation detection device

Abstract

A radiation detection system for detecting the presence and location of a radiation source includes an optical fiber bundle having fibers of different lengths, a radiation sensitive material, a stimulating source and an optical detector. The stimulating source stimulates the radiation sensitive material and the radiation sensitive material releases a light output, while the light output provides a readout signal for each fiber corresponding in intensity to the radiation received from the radiation source. The optical detector receives the readout signal such that the variations in intensity of the readout signals along the length of the bundle determine the presence and general location of the radiation source.

1 . A radiation detection system for enhancing detection signal to noise comprising:
 a first layer having at least one light source configured to stimulate light emission from a radiation sensitive energy storage material;   a second layer adjoining the first layer, the second layer comprising at least one radiation sensor having a first surface and a second surface, the at least one radiation sensor comprising a radiation sensitive material, wherein the radiation sensitive material stores energy corresponding to the radiation sensitive material's received radiation dose when it is exposed to radiation from a radiation source over a variable period of time;   wherein the at least one light source provides to the radiation sensitive energy storage material a stimulating light energy having a first wavelength where upon the radiation sensitive energy storage material releases at least a portion of the stored energy in the form of a light output having a second wavelength, wherein said light output provides a readout signal, wherein the readout signal is used to determine the energy and intensity of the radiation from the radiation source;   a third layer adjoining the second layer, the third layer comprising an optical detector configured to receive the readout signal and measure the intensity of the light output at the second wavelength, wherein the light output at the second wavelength corresponds in intensity to the intensity of the radiation from the radiation source; and   an optical filter positioned between the second and third layers, the optical filter configured to block the stimulating light energy provided by the at least one stimulating light source from interacting directly with the optical detector.   
   
   
       2 . The radiation detection system of  claim 1 , wherein the radiation sensitive material is an optically stimulated luminescent material. 
   
   
       3 . The radiation detection system of  claim 1 , wherein the at least one light source is one of a light emitting diode, a field emission display, an organic light emitting diode, a light emitting plasma discharge tube, a laser and a vacuum fluorescent tube. 
   
   
       4 . The radiation detection system of  claim 1 , wherein the first wavelength is longer than the second wavelength, wherein the first wavelength is in the infrared wavelength range and wherein the second wavelength is in the visible wavelength range. 
   
   
       5 . The radiation detection system of  claim 1 , wherein the first wavelength is in a shorter wavelength range than the second wavelength, wherein the first wavelength is in the ultraviolet wavelength range and wherein the second wavelength is in the visible wavelength range. 
   
   
       6 . The radiation detection system of  claim 1 , wherein the at least one light source is coupled to the first surface of the at least one radiation sensor. 
   
   
       7 . The radiation detection system of  claim 6 , wherein the at least one light source is coupled to the first surface of the at least one radiation sensor by means of one of a light pipe, a fiber optic plate, and a tapered fiber bundle. 
   
   
       8 . The radiation detection system of  claim 6 , wherein the optical detector is coupled to the at least one radiation sensor, wherein the optical detector comprises an optical sensor element having a third surface, wherein the third surface is coupled to the second surface of the at least one radiation sensor. 
   
   
       9 . The radiation detection system of  claim 8 , wherein the optical sensor element comprises a time integrating sensor, wherein the time integrating sensor is one of a charge coupled device and a complementary metal oxide semiconductor 
   
   
       10 . The radiation detection of system  claim 9 , wherein the optical detector is coupled to the at least one radiation sensor by means of one of a light pipe, a fiber optic plate, and a tapered fiber bundle. 
   
   
       11 . A radiation detection system for detecting the presence and location of a radiation source, the radiation detection device comprising:
 at least one bundle of optical fibers of different lengths, each fiber of the at least one bundle having a first end and second end, wherein the first ends share a common longitudinal location and the location of the second ends is determined by the length of each fiber, wherein each fiber comprises a radiation sensitive material, wherein the radiation sensitive material stores energy when it receives radiation from the radiation source;   at least one stimulating source for supplying stimulation to the radiation sensitive material, wherein the radiation sensitive material releases the stored energy corresponding to the radiation sensitive material's received radiation dose as a light output when it is exposed to the stimulating source, the light output providing a readout signal for each fiber, wherein the readout signal corresponds in intensity to the radiation received by each fiber from the radiation source, wherein the total energy of the radiation dose received by each fiber depends upon the fiber length;   at least one optical detector for receiving the readout signal, wherein the at least one optical detector is configured to detect variations in intensity of the readout signals along the length of the bundle and determine the general location of the radiation source based on the intensity of the readout signal from different members of the bundle having different lengths exposed to the radiation source.   
   
   
       12 . The radiation detection system of  claim 11 , wherein the radiation sensitive material is an optically stimulated luminescent material. 
   
   
       13 . The radiation detection system of  claim 11 , wherein the radiation sensitive material is a thermal luminescent detector material. 
   
   
       14 . The radiation detection system of  claim 11 , wherein the at least one stimulating source is coupled to the first ends of the bundle of optical fibers, wherein the at least one optical detector detects the light output at said first ends. 
   
   
       15 . The radiation detection system of  claim 11 , wherein the at least one stimulating source is coupled to the first ends of the bundle of optical fibers, wherein the at least one optical detector detects the light output at the second ends. 
   
   
       16 . The radiation detection system of  claim 11 , wherein each fiber comprises a core having an outer wall and an inner wall surrounding a transmission channel, wherein the inner wall is coated with a cladding layer of radiation sensitive material. 
   
   
       17 . The radiation detection system of  claim 16 , wherein the cladding layer interacts with a fluorescent dye material located within the core, wherein the fluorescent material absorbs a portion of the stimulated light output released from the radiation sensitive material and re-radiates light at a longer wavelength, wherein the re-radiated light is substantially trapped within each fiber and transmitted along the fiber to the at least one optical detector. 
   
   
       18 . The radiation detection system of  claim 16 , wherein the outer wall is coated with a reflective coating, wherein the reflective coating optically isolates each fiber and redirects a portion of the stimulated light output released from the radiation sensitive material back toward the transmission channel, wherein the redirected light output is transmitted to the at least one optical detector. 
   
   
       19 . The radiation detection system of  claim 11 , wherein each fiber comprises a hollow tube having an outer wall and an inner wall surrounding a transmission channel, wherein the inner wall is coated with a layer of radiation sensitive material, wherein the outer wall is coated with a reflective coating, wherein the reflective coating optically isolates each fiber and redirects the stimulated light output released from the radiation sensitive material back toward the transmission channel, wherein the redirected light output is transmitted to the at least one optical detector. 
   
   
       20 . The radiation detection system of  claim 19 , wherein the hollow tube is comprised of a glass substantially transparent in the stimulated wavelength region. 
   
   
       21 . The radiation detection system of  claim 19 , wherein the hollow tube is comprised of a polymer substantially transparent in the stimulated wavelength region. 
   
   
       22 . The radiation detection system of  claim 11 , wherein each fiber comprises a radiation sensitive material having particular sensitivity to specific radiation energies, wherein each fiber responds selectively to radiation in a specific range of energies. 
   
   
       23 . The radiation detection system of  claim 11 , wherein the at least one optical detector detects a readout signal during a data collection period, wherein the detection device comprises a controller for controlling the timing of the data collection period such that the detection of a readout signal having a radiation energy below a threshold results in extending the data collection period until the at least one optical detector detects a readout signal having a radiation energy above a threshold. 
   
   
       24 . The radiation detection device of  claim 11 , wherein the at least one optical detector comprises an array of individually readable light detectors arranged such that the individually readable light detectors are coupled to individual fibers, wherein the array comprises one of a charge coupled detector and a complimentary metal oxide semiconductor array. 
   
   
       25 . A radiation detection system for detecting the presence and location of a radiation source, the radiation detection device comprising:
 a two-dimensional array of optical fibers arranged in a generally planar area, wherein the fibers comprise a radiation sensitive material, wherein the radiation sensitive material stores energy when it is exposed to radiation from a radiation source;   at least one stimulating source for supplying stimulation to the radiation sensitive material, wherein the radiation sensitive material releases the stored energy in the form of a light output when it is exposed to the stimulating source;   at least one optical detector configured to examine the array of optical fibers that are optically stimulated and output a signal comprising an image of areas of the array of optical fibers exposed, wherein areas exposed to radiation produce a lighter image and areas not exposed to radiation produce a darker image, wherein the lighter and darker images combine to produce an image of the radiation source suitable for the identification of the energy and location of the radiation source.