Aim To describe accumulating frames characteristics of CCD camera as a night vision detector. Methods Utilizing CCD external trigger, computer video capture card and image processing software, the image accumul...Aim To describe accumulating frames characteristics of CCD camera as a night vision detector. Methods Utilizing CCD external trigger, computer video capture card and image processing software, the image accumulation was made. Results The detection of the static object image whose illuminance on the CCD FPA(focal plane array) was less than 3 7×10 -5 lx was realized and the image's resolution of 300?TV lines was achieved. Conclusion This experimental system can provide a kind of night vision device capable of detecting the static object at low light level and with low cost compared to an image intensifier.展开更多
To control the steady-state operation of Tokamak plasma, it is crucial to accurately obtain its shape and position. This paper presents a method for use in rapidly detecting plasma configuration during discharge of th...To control the steady-state operation of Tokamak plasma, it is crucial to accurately obtain its shape and position. This paper presents a method for use in rapidly detecting plasma configuration during discharge of the Experimental Advanced Superconducting Tokamak device. First, a visible/infrared integrated endoscopy diagnostic system with a large field of view is introduced,and the PCO.edge5.5 camera in this system is used to acquire a plasma discharge image. Based on the analysis of various traditional edge detection algorithms, an improved wavelet edge detection algorithm is then introduced to identify the edge of the plasma. In this method, the local maximum of the modulus of wavelet transform is searched along four gradient directions, and the adaptive threshold is adopted. Finally, the detected boundary is fitted using the least square iterative method to accurately obtain the position of the plasma. Experimental results obtained using the EAST device show that the method presented in this paper can realize expected goals and produce ideal effects;this method thus has significant potential for application in further feedback control of plasma.展开更多
The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical co...The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical considerations pertinent to choosing the right CCD camera and unveiling the principles underlying multifarious parameters. Therefore, this analysis can be a valuable tool in scrutinizing each parameter and clarifying proper usage of a scientific CCD camera.展开更多
Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras （PCO SensiCam） situated detecting simultaneously the radiation of argon and nitrogen. The evaluation of image differen...Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras （PCO SensiCam） situated detecting simultaneously the radiation of argon and nitrogen. The evaluation of image differences between two records showed that the location of regions on plasma jet boundaries characterised by stronger nitrogen radiation changes with the plasma flow rate. Close-to-laminar flow results in a small mixing rate and consequently low nitrogen optical emission on plasma jet boundaries. The increase of the flow rate leads to the formation of a relatively thick and stable layer on the boundaries characterised by strong nitrogen radiation. Further enhancement of the flow rate results in the formation of unstable regions of excited nitrogen molecules moving along the jet.展开更多
The 2D CCD camera has been used to take photos during hydrogen multi-pellet injection in HL-1M tokamak. The hydrogen multi-pellet (2 × 1.0 mm, 3× 1.2 mm, 3×1.2 ~ 1.3 mm) is horizontally injected into ...The 2D CCD camera has been used to take photos during hydrogen multi-pellet injection in HL-1M tokamak. The hydrogen multi-pellet (2 × 1.0 mm, 3× 1.2 mm, 3×1.2 ~ 1.3 mm) is horizontally injected into plasma. The observation is performed above the injection path at a sight angle 13.4°，As the shape of cloud ablation varies so quickly, the key points of the experiment have to be the high temporal resolution of CCD and the determination of pellet radial location in plasma. A series of improvements have been made with the experiment setup, including camera parameter, control (NA, ROI) and trigger mode, so as to satisfy the experiment requirements. Thus very nice photos along with the satisfying experimental results are obtained such as: (1) single exposure time reduced to 100 us (2) multi-frame in one discharge (FPS≥ 40) (3)multi-exposure for one pellet so that further observation of the temporal process of pellet ablation may be possible. Through the data analysis on the spatial distibution of pellet ablation clouds in photos taken, the pellet dimensions, trajectory of the cloud and pellet velocity are obtained, and the physical mechanism of pellet-plasma interactions also analyzed. In particular, it is possible to provide an effective means for measuring q-profile of HL-1M plasma.展开更多
文摘Aim To describe accumulating frames characteristics of CCD camera as a night vision detector. Methods Utilizing CCD external trigger, computer video capture card and image processing software, the image accumulation was made. Results The detection of the static object image whose illuminance on the CCD FPA(focal plane array) was less than 3 7×10 -5 lx was realized and the image's resolution of 300?TV lines was achieved. Conclusion This experimental system can provide a kind of night vision device capable of detecting the static object at low light level and with low cost compared to an image intensifier.
基金supported by the National Natural Science Foundation of China(Nos.11105028 and 51505120)the National Magnetic Confinement Fusion Science Program of China(No.2015GB102004)
文摘To control the steady-state operation of Tokamak plasma, it is crucial to accurately obtain its shape and position. This paper presents a method for use in rapidly detecting plasma configuration during discharge of the Experimental Advanced Superconducting Tokamak device. First, a visible/infrared integrated endoscopy diagnostic system with a large field of view is introduced,and the PCO.edge5.5 camera in this system is used to acquire a plasma discharge image. Based on the analysis of various traditional edge detection algorithms, an improved wavelet edge detection algorithm is then introduced to identify the edge of the plasma. In this method, the local maximum of the modulus of wavelet transform is searched along four gradient directions, and the adaptive threshold is adopted. Finally, the detected boundary is fitted using the least square iterative method to accurately obtain the position of the plasma. Experimental results obtained using the EAST device show that the method presented in this paper can realize expected goals and produce ideal effects;this method thus has significant potential for application in further feedback control of plasma.
基金supported by the the National Major Technologies R&D Programme of China during the 10th Five-Year Plan Period(No.2001BA302B)the National Science Foundation for Distinguished Young Scholars(No.10225526)+1 种基金the Knowledge Innovation Programme of the Chinese Academy of Sciences(No.KSCX2-SW-324)the Foundation for University Key Teacher by the Ministry of Education(No.2005jq1135).
文摘The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical considerations pertinent to choosing the right CCD camera and unveiling the principles underlying multifarious parameters. Therefore, this analysis can be a valuable tool in scrutinizing each parameter and clarifying proper usage of a scientific CCD camera.
基金the Czech Science Foundation under the contract 202/05/0728
文摘Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras （PCO SensiCam） situated detecting simultaneously the radiation of argon and nitrogen. The evaluation of image differences between two records showed that the location of regions on plasma jet boundaries characterised by stronger nitrogen radiation changes with the plasma flow rate. Close-to-laminar flow results in a small mixing rate and consequently low nitrogen optical emission on plasma jet boundaries. The increase of the flow rate leads to the formation of a relatively thick and stable layer on the boundaries characterised by strong nitrogen radiation. Further enhancement of the flow rate results in the formation of unstable regions of excited nitrogen molecules moving along the jet.
文摘The 2D CCD camera has been used to take photos during hydrogen multi-pellet injection in HL-1M tokamak. The hydrogen multi-pellet (2 × 1.0 mm, 3× 1.2 mm, 3×1.2 ~ 1.3 mm) is horizontally injected into plasma. The observation is performed above the injection path at a sight angle 13.4°，As the shape of cloud ablation varies so quickly, the key points of the experiment have to be the high temporal resolution of CCD and the determination of pellet radial location in plasma. A series of improvements have been made with the experiment setup, including camera parameter, control (NA, ROI) and trigger mode, so as to satisfy the experiment requirements. Thus very nice photos along with the satisfying experimental results are obtained such as: (1) single exposure time reduced to 100 us (2) multi-frame in one discharge (FPS≥ 40) (3)multi-exposure for one pellet so that further observation of the temporal process of pellet ablation may be possible. Through the data analysis on the spatial distibution of pellet ablation clouds in photos taken, the pellet dimensions, trajectory of the cloud and pellet velocity are obtained, and the physical mechanism of pellet-plasma interactions also analyzed. In particular, it is possible to provide an effective means for measuring q-profile of HL-1M plasma.
