In this third part of a multi-paper series, we present quantitative image reconstruction results from aerial measurements of eight different surrogate distributed gammaray sources on flat terrain. We show that our qua...
详细信息
Molten salt has attracted the attention of researchers, especially as a coolant because of its characteristics. This study aimed to analyse the transient and steady-state of the natural circulation system in the molte...
详细信息
Smart windows have energy-saving potential in buildings in tropical climates. Characterized by high solar radiation, humidity, and temperature, tropical climates demand innovative solutions for energy-efficient buildi...
详细信息
The detection and localization of radiological and nuclear materials at standoff distances of 20 m or more in urban and cluttered environments remains a challenge in nuclear security and proliferation detection. Previ...
详细信息
ISBN:
(数字)9798350388152
ISBN:
(纸本)9798350388169
The detection and localization of radiological and nuclear materials at standoff distances of 20 m or more in urban and cluttered environments remains a challenge in nuclear security and proliferation detection. Previous approaches have explored large-area radiation imaging methodologies based on planar arrangements of detectors with passive masks, leading to limited field-of-view (FOV) and efficiency. We have developed the Cylindrical Active Mask Imaging System (CAMIS) which consists of $128(10 \mathrm{cm}) 3 \mathrm{NaI}(\mathrm{Tl})$ detectors arranged in a cylindrical configuration providing gamma-ray imaging capabilities with a 360 o azimuthal FOV. We have mounted this system within an electric van to detect and localize radioactive sources more than 100 meters away. Complemented with a multi-beam rotating LiDAR system, multiple large FOV optical cameras, and several contextual sensor data streams, this system will allow for the localization of these sources in dense urban landscapes. This system will also provide more detailed and sensitive mapping of background radiation fluctuations in the environment than previous large mobile radiation detection platforms. We present initial results in the detection and localization of sources in standoff distances of more than 100 m using a fully mobile platform
This study explores the calculation of Reference Discontinuity Factors (RDFs) using Serpent, focusing on the methodology and potential pitfalls. In two-step reactor analyses, consistently generated RDFs are crucial fo...
With advances in single sided handheld backscatter imaging and their incorporation into security applications, detector characterization is essential to operator feedback, image enhancement, and decision making. While...
详细信息
ISBN:
(数字)9798350388152
ISBN:
(纸本)9798350388169
With advances in single sided handheld backscatter imaging and their incorporation into security applications, detector characterization is essential to operator feedback, image enhancement, and decision making. While a well-trained operator has the ability to discern contraband materials during inspections, understanding the limits of an imager’s resolution at varying distances inform additional inspections or advise threat scenarios. This research characterizes the detector response of a Nighthawk handheld backscatter imaging device developed by Viken Detection in laboratory conditions utilizing High-Density Polyethylene (HDPE) phantoms. The Nighthawk uses a collimated millimeter-sized pencil x-ray beam that scans 150 times per second laterally along a fan arc to generate a series of 1D linear images and then compile to a 2D image of the phantom. Sampling occurred using line pair bar slits of different interval frequencies and the straight edges of the HDPE phantoms at different separation distances from the NightHawk front surface ranging from 10 centimeters to 1 meters. The Nighthawk was placed on a moving table while phantom was kept stationary to maintain consistent scan speed during image capture. Image processing relied on analyzing the contrast visibilities of line pair phantoms and edge responses of a slanted edge phantom. The slanted edge image allowed over-sampling a sharp edge and then an Edge Spread Function and Modulation Transfer Function were derived to characterize system resolutions at different imaging distances.
We have built a scalable mixed-signal readout circuit for a 3D position sensitive PET detector that achieves ~100 ps FWHM CTR. For this work we used individual 3×3×3 mm3 and 3×3×10 mm3 LGSO crystal...
In DFT calculation, a basis set is an important factor in determining the quality of results, especially for hyperfine interaction where changes in the local geometry and electronic structure can have a big impact. Th...
详细信息
Developing high sensitivity multiparametric medical imaging tools constitutes one of the main research topics in radionuclide *** time-of-flight positron emission tomography (TOF-PET) scanners have shown potential in ...
We have designed a novel electronic readout with 24:1 multiplexing ratio of the timing channels that achieves 100 ps coincidence time resolution. The detector layer units comprise 2×4 arrays of 3×3×10 m...
暂无评论