Yan Yiming

An investigation of X-ray fluorescence analysis with an X-ray focusing system (X-ray lens)

Abstract Divergent X-ray radiation has been focused into a small spot (diameter 500 μm) by an X-ray lens made of polycapillaries, increasing the power density by 10 4 times. The new X-ray lens has been applied to the XRF technique. Limits of detection of 10 −9 −10 −10 g have been obtained by means of the new technique with an X-ray tube of 2 W power.

Transmission Efficiency of X-Rays Through a Cylinder Capillary

A new model for calculating the transmission efficiency of x-rays through a cylinder capillary is proposed. The model is based on some reasonable physical and mathematical assumptions. The calculation results given by the model have satisfactory intrinsic consistency and can get quite a good fit to the experimental results.

The Evaluation of Neutron Resonance Parameters

The neutron resonance parameters as well as the thermal neutron cross sections of more than fifty nuclides have been evaluated for CENDL. From the recommended resolved resonance parameters, the average resonance parameters have been estimated and recommended. Some characteristics of the average parameters have been studied. Efforts are being made to compare the cross sections calculated on the basis of the evaluated parameters with the measured ones and to obtain the residual cross sections.