Papers by Keyword: Particle Detector

Abstract: High voltage Gas Insulated Switchgear (GIS) is prone to metallic particles. The particle void can reduce the dielectric strength of the insulation material of SF6 gas. This paper discusses the developed particle detector for GIS using a new approach by using image processing to reduce flashover phenomena occurring on energized GIS. The particle detector consists of borescope, laptop and a detection program. The program was coded using MATLAB using image processing algorithm. The in-lab test was conducted on the simulated GIS to see the effectiveness of the particle detector to detect small particles inside the narrow GIS enclosure. In real world application, the borescope will be inserted through GIS access hole before filling the enclosure with SF6 gas. This new approach is proposed to be conducted during the erection and commissioning of new GIS. This new approach looks promising because it can reduce flashover phenomena caused by existence of metallic particle and also reduces Greenhouse gas emission to the air.

Abstract: Defects in electron-irradiated 6H-SiC diodes have been studied by single alpha particle induced charge transient spectroscopy and deep level transient spectroscopy (DLTS) in order to identify critical defects responsible for the charge collection efficiency (CCE) decreased by high-energy electron irradiation. The defect X2 detected by the charge transient spectroscopy and the electron trap Ei detected by the DLTS had a similar activation energy of around 0.50 eV. In addition, the annealing at 200oC completely removed defects X2 and Ei, and restored the CCE. The defect X2 is attributed to the electron trap Ei, and responsible for the decreased CCE.

Abstract: The effect of electron irradiation on the charge collection efficiency of a 6H-SiC p+n diode has been studied. The diodes were irradiated with electrons of energies from 100 keV to 1 MeV. The charge collection efficiencies of the samples were measured for alpha particles before and after the electron irradiation. The electron irradiation at 100 keV does not affect the charge collection efficiency, while the electron irradiation at 200 keV or higher decreases the charge collection efficiency. The degree of the degradation of the diodes correlates with the energy of the electron irradiation.