Rights statement: This is an author-created, un-copyedited version of an article accepted for publication/published in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1748-0221/14/02/P02007
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Gamma-ray modulation properties of tungsten coded apertures for a novel mixed-field imaging system
AU - Cieslak, Michal
AU - Akurugoda Gamage, Kelum
AU - Glover, Robert
AU - Taylor, Charles James
N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1748-0221/14/02/P02007
PY - 2019/2/8
Y1 - 2019/2/8
N2 - An investigation into the gamma-ray modulation properties of a tungsten coded aperture, whose design is based on the mathematical principles of Modified Uniformly Redundant Arrays (MURA), has been performed. Due to the small size of the individual cells, the aperture was built using additive manufacturing methods. The gamma-ray field was produced by a 137-Cs radioactive isotope at Lancaster University, UK. An organic plastic scintillator sample, which is capable of pulse shape discrimination, has been used to detect the gamma-ray field modulated by a tungsten aperture. Prior to the investigation of the aperture modulation properties, energy calibration of the scintillator was performed. Its pulse shape discrimination capabilities were verified using a 252-Cf fission source. In this study, each of 169 coded aperture cells were investigated by collimating the modulated gamma-ray field of 137-Cs through a 25.4 mm thick lead supporting plate. The supporting plate has one opening in the centre, of the same dimensions as the single aperture cell, i.e. 2.5 mm by 2.5 mm. The number of pulses detected for every aperture location were recorded in an array. The array was subsequently used to create a two-dimensional image of the source, which was encoded through the coded aperture pattern. Finally, the image was decoded using deconvolution techniques to reveal the actual source location. The new results obtained in this study indicate that sufficient gamma-ray modulation properties of the aperture can be determined, despite the relatively small footprint and thickness of the coded aperture.
AB - An investigation into the gamma-ray modulation properties of a tungsten coded aperture, whose design is based on the mathematical principles of Modified Uniformly Redundant Arrays (MURA), has been performed. Due to the small size of the individual cells, the aperture was built using additive manufacturing methods. The gamma-ray field was produced by a 137-Cs radioactive isotope at Lancaster University, UK. An organic plastic scintillator sample, which is capable of pulse shape discrimination, has been used to detect the gamma-ray field modulated by a tungsten aperture. Prior to the investigation of the aperture modulation properties, energy calibration of the scintillator was performed. Its pulse shape discrimination capabilities were verified using a 252-Cf fission source. In this study, each of 169 coded aperture cells were investigated by collimating the modulated gamma-ray field of 137-Cs through a 25.4 mm thick lead supporting plate. The supporting plate has one opening in the centre, of the same dimensions as the single aperture cell, i.e. 2.5 mm by 2.5 mm. The number of pulses detected for every aperture location were recorded in an array. The array was subsequently used to create a two-dimensional image of the source, which was encoded through the coded aperture pattern. Finally, the image was decoded using deconvolution techniques to reveal the actual source location. The new results obtained in this study indicate that sufficient gamma-ray modulation properties of the aperture can be determined, despite the relatively small footprint and thickness of the coded aperture.
KW - scintillators
KW - gamma detectors
KW - neutron detectors
KW - image processing
KW - scintillation
KW - light emission processes
U2 - 10.1088/1748-0221/14/02/P02007
DO - 10.1088/1748-0221/14/02/P02007
M3 - Journal article
VL - 14
JO - Journal of Instrumentation
JF - Journal of Instrumentation
SN - 1748-0221
M1 - P02007
ER -