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Title: Radiation detector based on a matrix of crossed wavelength-shifting fibers

Abstract

A radiation detection system comprising a detection grid of wavelength shifting fibers with a volume of scintillating material at the intersecting points of the fibers. Light detectors, preferably Silicon Photomultipliers, are positioned at the ends of the fibers. The position of radiation is determined from data obtained from the detection grid. The system is easily scalable, customizable, and also suitable for use in soil and underground applications. An alternate embodiment employs a fiber grid sheet or layer which is comprised of multiple fibers secured to one another within the same plane. This embodiment further includes shielding in order to prevent radiation cross-talk within the grid layer.

Inventors:
; ; ;
Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1351071
Patent Number(s):
9,618,630
Application Number:
15/008,499
Assignee:
JEFFERSON SCIENCE ASSOCIATES, LLC TJNAF
DOE Contract Number:
AC05-06OR23177
Resource Type:
Patent
Resource Relation:
Patent File Date: 2016 Jan 28
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 36 MATERIALS SCIENCE

Citation Formats

Kross, Brian J., Weisenberger, Andrew, Zorn, Carl, and Xi, Wenze. Radiation detector based on a matrix of crossed wavelength-shifting fibers. United States: N. p., 2017. Web.
Kross, Brian J., Weisenberger, Andrew, Zorn, Carl, & Xi, Wenze. Radiation detector based on a matrix of crossed wavelength-shifting fibers. United States.
Kross, Brian J., Weisenberger, Andrew, Zorn, Carl, and Xi, Wenze. Tue . "Radiation detector based on a matrix of crossed wavelength-shifting fibers". United States. doi:. https://www.osti.gov/servlets/purl/1351071.
@article{osti_1351071,
title = {Radiation detector based on a matrix of crossed wavelength-shifting fibers},
author = {Kross, Brian J. and Weisenberger, Andrew and Zorn, Carl and Xi, Wenze},
abstractNote = {A radiation detection system comprising a detection grid of wavelength shifting fibers with a volume of scintillating material at the intersecting points of the fibers. Light detectors, preferably Silicon Photomultipliers, are positioned at the ends of the fibers. The position of radiation is determined from data obtained from the detection grid. The system is easily scalable, customizable, and also suitable for use in soil and underground applications. An alternate embodiment employs a fiber grid sheet or layer which is comprised of multiple fibers secured to one another within the same plane. This embodiment further includes shielding in order to prevent radiation cross-talk within the grid layer.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Apr 11 00:00:00 EDT 2017},
month = {Tue Apr 11 00:00:00 EDT 2017}
}

Patent:

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  • A novel detector element structure and method for its use is provided. In a preferred embodiment, one or more inorganic scintillating crystals are coupled through wavelength shifting optical fibers (WLSFs) to position sensitive photomultipliers (PS-PMTs). The superior detector configuration in accordance with this invention is designed for an array of applications in high spatial resolution gamma ray sensing with particular application to SPECT, PET and PVI imaging systems. The design provides better position resolution than prior art devices at a lower total cost. By employing wavelength shifting fibers (WLSFs), the sensor configuration of this invention can operate with a significantmore » reduction in the number of photomultipliers and electronics channels, while potentially improving the resolution of the system by allowing three dimensional reconstruction of energy deposition positions. 11 figs.« less
  • A novel detector element structure and method for its use is provided. In a preferred embodiment, one or more inorganic scintillating crystals are coupled through wavelength shifting optical fibers (WLSFs) to position sensitive photomultipliers (PS-PMTs). The superior detector configuration in accordance with this invention is designed for an array of applications in high spatial resolution gamma ray sensing with particular application to SPECT, PET and PVI imaging systems. The design provides better position resolution than prior art devices at a lower total cost. By employing wavelength shifting fibers (WLSFs), the sensor configuration of this invention can operate with a significantmore » reduction in the number of photomultipliers and electronics channels, while potentially improving the resolution of the system by allowing three dimensional reconstruction of energy deposition positions.« less
  • Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Details about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred KURARAY, Y-11, multiclad, 1.2mm outer diameter wavelength shifting fibers each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers have a response within 1% of the overall mean.
  • We are developing a PET detector with depth of interaction (DOI) sensitivity for breast and small animal imaging. The detector uses layers of high density scintillators sandwiched between orthogonal ribbons of wavelength shifting optical fibers. The fibers are coupled to microchannel plate (MCP) based, position sensitive photomultiplier tubes (PSPMTs) containing a crossed delay line readout anode. Preliminary measurements have been made using blue-green waveshifting fiber ribbons coupled to LSO. The measured photoelectron yield due to wavelength shifted light from the fibers is sufficient to ensure a Poisson probability of only 1.0% that no photoelectron is generated in a given MCPmore » PSPMT. Measurement of internally reflected scintillation light permits energy resolution of better than 25% at 511 keV. Optical fiber readout of high density inorganic crystals provides significantly larger detective area per unit phototube area than do one-to-one coupling schemes using PSPMTs. The use of the MCP PSPMT solves problems that have prevented other types of PSPMTs from being used in such a configuration, namely poor resolution at the low light output level of the optical fibers.« less
  • The chemical compatibility of wave length shifting fibers with several liquid scintillators has been investigated. Based on systematic characterization of the behavior of the BC-517 family, a time of life of 70{endash}450 years was estimated for the polystyrene based wave length shifting fiber in BC-517P scintillator. WLS (wavelength shifting) fibers irradiated continuously to a dose of 6.4 Mrads (at .377Mrad/hr of Co-60) were observed to decrease from 100% to 5% transmission; however, after 100 hours of annealing, the transmission increased to 90%. Geant simulations of a simplified calorimeter located behind a BaF2 electromagnetic calorimeter for the GEM detector at SSCmore » showed that the constant term in the energy resolution will change from 1.8 to 2.9 in five years at 10{star}{star}34 luminosity for psuedorapidity eta=3.« less