NON DESTRUCTIVE QUANTITATIVE DOPANT PROFILING TECHNIQUE BY X RAY RADIOGRAPHY : DOPANT MODEL - METHOD CAPABILITY

Laser targets specifications have stringent dimensional accuracy requirements on target components, especially on compositional levels of silicon and oxygen. A charge-coupled-device - based X-ray radiography instrument is used in target metrology where sample density precludes the use of optical techniques. In this work, we present a dopant model using an X-ray digital radiographic system. This model comes from an X-ray transmission method for dimension measurement. It links the transmitted X-ray energy to the gray level on the image through each point of the microshell. The complete X-ray radiography system has to be well known to use this method, that is to say the X-ray spectrum, the sensor response, the linearity of the sensor, and so on… The complete system is modelled with CIVA software. Experimental results on plastic samples agree with theoretical results. The method sensitivity is studied by comparing modelled images of microshell with varying parameters. The conclusion is that the X-ray digital radiographic system has a sensitivity enough to detect 4 % at. of oxygen and 0,5 % at. of silicon.