- 标题
- 摘要
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- 实验方案
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Imaging of plutonium particles using a CCD-camera-based alpha-particle imaging system
摘要： Measuring individual activities of Plutonium dioxide (PuO2) particles is extremely important for the internal exposure of a worker to these particles. For this purpose, a film-based autoradiographic camera, Imaging Plates, and a SiPM-based alpha particle imaging detector have been used in a site of nuclear facilities. However, there is a room for improvement regarding a spatial resolution or a quantification of activity. Recently, an alpha imaging system using a cooled CCD camera has been developed and used for detecting Pu contamination in a glove box. In this study, actual PuO2 particles were measured using the CCD-camera-based alpha-particle imaging system, and the system’s effectiveness was proven by comparing to conventional systems. An electron multiplying (EM) CCD Camera (ImagEM X2 C9100-23B, Hamamatsu, Japan) was used for alpha particle imaging in this study. A Pu sample was placed on top of the ZnS(Ag) scintillator, and produced scintillation light was captured using the CCD camera. The number of alpha particles on a 2-dimensional distribution image was measured to convert into activity. The frame rate for obtaining the image was set to 33.3 frames/s (at 30 ms intervals). This study showed that the CCD camera-based alpha-particle imaging system has some advantages compared to the conventional alpha particle imaging systems; 1) High spatial resolution, 2) Counting capability of individual alpha particles, 3) Real-time imaging.
关键词： EM-CCD camera,alpha particle,imaging,Plutonium dioxide particles
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 27th Asian Test Symposium (ATS) - Hefei, China (2018.10.15-2018.10.18)] 2018 IEEE 27th Asian Test Symposium (ATS) - Test Diagnosis of Digital Microfluidic Biochips Using Image Segmentation
摘要： Digital micro?uidic biochip has been developed as a promising alternative to the traditional approach of benchtop laboratory tests. Dependability is an important biochemical attribute for micro?uidic biochips that are used for safety-critical applications, such as point-of-care health assessment, air-quality monitoring, and food-safety testing. Therefore, the robust of?ine and online test techniques are required after manufacturing and during bioassay operations. In this work, we are presenting an image segmentation based testing methodology to detect the catastrophic faults and to locate the faulty cells. The design-for diagnosability scheme is proposed, and it is shown that faults can be located and tolerated by providing alternative paths in biochips. Moreover this testing method also facilitates the testing of a biochip with other bioassay operations running concurrently.
关键词： fault models,CCD,Biochip,electrowetting,image segmentation,test time
更新于2025-09-04 15:30:14
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Image-Forming System Design of Dynamic Targets Based on Reflecting Mirror Splicing
摘要： In this paper, the author designed an area-scan CCD reflecting mirror splicing image-forming system with area-scan CCD ICX415AL as its transducer module and this system can be used for tracking dynamic targets. By analyzing the theory of vignetting generating, the author made mathematic model of vignetting and confirmed the splicing and overlapping pixel number of the optical system. What’s more, the sequential circuit and driving power circuit of ICX415ALwas designed and the correlated noise in video signals was strained with CDS technology. Therefore, the signal-to-noise ratio (SNR) of the system was elevated. With FPGA as its core controlling module, this system postponed the splicing image-forming system to a period during which a line of CCD data are read, thus the need of real-time tracking was completely met.
关键词： dynamic targets,FPGA,area-scan CCD,reflecting mirror
更新于2025-09-04 15:30:14
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High resolution, high signal-to-noise crystal spectrometer for measurements of line shifts in high-density plasmas
摘要： The Orion high-resolution x-ray (OHREX) spectrometer has been a successful tool for measuring the shapes of density-broadened spectral lines produced in short-pulse heated plasmas at the Orion laser facility. We have recently out?tted the instrument with a charge-couple device (CCD) camera, which greatly increased the accuracy with which we can perform line-shift measurements. Because OHREX is located on the outside of the Orion target chamber, no provisions for the shielding of electromagnetic pulses are required. With the CCD, we obtained a higher signal-to-noise ratio than we previously obtained with an image-plate detector. This allowed us to observe structure in the image produced by the diffraction from the two OHREX crystals, which was highly reproducible from shot to shot. This structure will ultimately limit the accuracy of our spectroscopic measurements.
关键词： high-resolution x-ray spectrometer,CCD camera,signal-to-noise ratio,high-density plasmas,line shifts
更新于2025-09-04 15:30:14
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Error Analysis and Compensation in Images stitching for the Mechanically Stitched CCD Aerial Cameras
摘要： Image misalignment during image stitching is a common issue for the mechanically stitched CCDs in the aerial cameras due to the relative image motion between CCDs. In this paper, we analyze the error in imaging stitching for the mechanically stitched CCDs and propose a compensation method based on position and orientation system (POS). Firstly, the imaging relationship of overlapping pixels in mechanical stitching is analyzed. The imaging model of adjacent CCD is constructed according to the collinear equation. The effects of stitching staggered distance, carrier attitude change and flight speed on the image mosaic of overlapping areas are given. Monte Carlo algorithm is used to analyze the statistical value of image mosaic error in overlapping area under typical working conditions. Then, a geometric correction method based on POS recording of external orientation elements of adjacent CCD imaging is proposed. The overlapping area stitching error is reduced from 14.9 pixels to 0.4 pixels which meets the engineering requirements. The mechanical stitching mathematical model, analysis and correction method established in this paper have strong engineering and application significance for mechanical stitching of aerial cameras.
关键词： mechanically stitched CCD,aerial camera,POS-assisted geometric correction,error analysis
更新于2025-09-04 15:30:14