Time-Encoded Gamma-Ray Imaging Using a 3-D Position-Sensitive CdZnTe Detector Array

Brown, Steven T.; Goodman, David A.; Chu, Jiyang; Williams, Bennett; Williamson, Matthew J.; He, Zhong

doi:10.1109/tns.2019.2953182

Cited by 5 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Section 4 presents 3D source distribution estimation via a depth-refocusing technique. Although the depth-refocusing technique was previously used by Brown et al [6], we expand the technique and demonstrate it for extended sources distributed in 3 dimensions. This work is concluded with the 3D estimation of spatially extended special nuclear material from an experiment conducted at Idaho National Laboratory (INL).…”

Section: Jinst 16 P03013mentioning

confidence: 99%

“…The Mira system facilitates the movement of the mask [6]. It has two stepper motors to translate the mask horizontally and vertically, or the x and ŷ direction (see coordinate systems in figure 1).…”

Section: Mira the Time Encoding Imaging Systemmentioning

confidence: 99%

“…This work uses the digital OrionUM system that is capable of superior position resolution when compared to its analog predecessor used in the original prototype of the TEI system [6,16]. To demonstrate the benefit of implementing subpixel estimation, a 63 μCi 57 Co source was imaged with and without subpixel approximation.…”

Section: Implementation Of Subpixel Estimationmentioning

confidence: 99%

“…Estimation of depth in the image space, or 3D imaging, via the use of a coded aperture system has been accomplished in optical and gamma-ray cameras [6,[23][24][25]. Referencing (3.3), the magnification also depends on the 𝐴 distance or the source-to-mask distance.…”

Section: D Estimation Of Gamma-ray Sources Via Depth Refocusingmentioning

confidence: 99%

“…Time-encoded imaging (TEI) is an extension of coded aperture imaging, in that it uses a coded aperture to spatially encode the source, but also contains a temporal encoding component [5,6]. It can be accomplished via a space-and-time changing mask [7], self modulation [8], or a mobile coded mask [9].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Time encoded imaging of extended gamma-ray sources in 3D using the OrionUM pixelated CdZnTe with subpixel estimation and depth of interaction corrections

Shy¹,

Petryk²,

Chen³

et al. 2021

J. Inst.

View full text Add to dashboard Cite

Nuclear holdup, or the accumulation of material in processing equipment, is important to localize, identify, and quantify for economic reasons and criticality safety. As a part of the quantification process is to estimate the geometric distribution of the material, high-resolution 3D images are desired. To image gamma-ray material in 3D, we propose a time-encoded imaging technique that uses a mobile coded aperture to modulate the gamma-ray signal spatially and temporally. In the process, we investigate means to improve upon the image resolution. Naturally, the quality of the reconstructed image is dependent on the size of the aperture and the fidelity of the recorded projection, among other factors. The major degradation in the recorded projection originates from the poor position reconstruction of the gamma-ray interaction location within the detector. By utilizing the subpixel capabilities of the OrionUM pixelated CdZnTe system, the position of each gamma interaction can be estimated with a resolution of 500 μm full-width-at-half-maximum (FWHM) for a 120 keV gamma ray. With subpixel estimation, the average FWHM of a double-Gaussian fit improves by almost 10% when imaging two 57Co sources placed 1 cm apart. Next, by applying a collimator verified depth of interaction correction scheme, the image resolution improves by 7.5% and 12.3% for the FWHM and the full-width-at-tenth-maximum respectively for the studied source configuration. Finally, the estimation of the 3D distribution of a gamma-ray source is demonstrated via a depth refocusing technique. This technique is shown on spatially extended special nuclear material measured at Idaho National Laboratory and estimates the material's out of plane angle to within 20% of the true angle.

show abstract

Section: Jinst 16 P03013mentioning

confidence: 99%

Section: Mira the Time Encoding Imaging Systemmentioning

confidence: 99%

Section: Implementation Of Subpixel Estimationmentioning

confidence: 99%