The irradiation effect of DC-DC power converter under x-ray
The irradiation response of DC-DC power converter was studied using X-ray source with whole and local irradiation method. It was indicated that the irradiation response of the different part of circuit was represented different effect. The VDMOSFET of DC-DC power converter was tremendous irradiation affected, and PWM and Shottky diode was exiguous affected, and the trend of DC-DC power converter optical-coupler parameters affected by optical-coupler was reversely with other part of DC-DC circuits.
Total dose effects on power-MOSFET switching converters
Abstract Power MOSFETs have important applications in space systems, particularly in dc/dc power conversion. Transistors used in the space environment are subject to the effects of exposure to the natural radiation environment in space. Among the effects of ionizing radiation are shifts in threshold voltage and reduction of carrier mobility. In this work, the total-ionizing-dose-induced degradation of two switching power converters is examined. The MOSFETs for two switching converters were irradiated with a 60 Co source and their performance was evaluated in buck and boost converters. The experimental results agree well with values obtained from SPICE simulations.
Detection of Fractures Based on Directional Filtering in Image Logging
According to the feature of the direction of fractures in image logging, a method of fracture detection in image logging based on directional filtering is presented in this paper. The fracture image is filtered by the corresponding filter based on the local direction of fractures, which enhances the fracture traces in the direction of fractures in image logging. The final fracture traces are extracted by the combination of the results of both directional filtering and the threshold segmentation. Experimental results show this method effectively detect the fractures in image logging.