Longtao Yi

Property of slice square polycapillary x-ray optics

A geometrical description of square polycapillary x-ray optics and the basic theory of the transmission of x-rays are presented. A method of numerical calculation is developed based on ray-tracing theory. The method simulates the intensity distribution of x-rays propagating through slice square polycapillary x-ray optics. The simulation results are compared with the experimental results.

Vibration Sensor Approaches for the Monitoring of Sand Production in Bohai Bay

The real-time monitoring of sand production has always been an important issue during the process of oil production in offshore field. This paper illustrates a new alternative vibration sensor approach to monitor the sand production. A special broadband sensor was selected. Then the time-frequency analysis, characteristic sand frequency band filter method, and peak searching-denoising method were proposed to enhance the detection ability of sand vibration signals in strong background noises of crude oil flow. After that, visible differences in time-frequency domain and power spectrum between sand and nonsand production well can be observed. Four typical wells in Bohai oil production platform were selected to investigate the monitoring effects of sand production. The monitoring findings show that there exists a good correlation between the vibration power spectrum amplitude and the sand production volume, which is consistent with actual results.

Simulation of x-ray transmitted in the square polycapillary x-ray lens

To study the transmission property of the square polycapillary x-ray lens and verify its feasibility using in the x-ray pulsar navigation a geometrical description of it and the basic theory of the transmission of x-rays are presented. A method of numerical calculation is developed based on ray-tracing theory. The method simulates the intensity distribution and calculates the transmission efficiency of x-rays propagating through a square polycapillary lens. The transmission rule of the x-ray propagation in the x-ray lens can be got, after tracing a large number of x-ray beams. A program based on ray-tracing method was designed to simulate the transmission efficiency of an x-ray lens and the light spot gained from it. The transmission property of the square polycapillary x-ray lens is studied based on this program. And the study shows that the transmission property of the square polycapillary x-ray lens is good, and it has the potential of being used in the area of x-ray pulsar navigation.