Determination of Doping Concentration of ICF Shells by an Improved Equivalent Absorption Method Based on Real-Time X-Ray Imaging

Abstract

Noncontact radiography is developed to determine the doping concentration of inertial confinement fusion shells based on an improved equivalent absorption method by real-time X-ray imaging. Elements of high atomic number (high-Z)/middle atomic number (mid-Z) are doped into the shells to prevent hot electrons from preheating the fuel and to restrain the growth of hydromechanic instability. In this paper, an improved equivalent absorption model is developed to determine doping concentration by real-time X-ray imaging. Compared to contact radiography (CR) with film imaging, this technique can be used to obtain doping concentrations at different angles as a supplement to the CR method, even if the dynamic range of a charge-coupled device is less than film imaging. Experiments are carried out to determine the doping concentrations of Ge-doped and Si-doped shells. Uncertainties of the results are analyzed, and the expanded uncertainties are approximated to 0.1 at. % (K = 2, confidence factor). The experimental results show that there is a high level of agreement between this method and energy dispersive spectroscopy with the modified model.

Keywords:

• ICF shells
• real-time X-ray imaging
• equivalent absorption
• doping concentration

Acknowledgment

This work was supported by the National Natural Science Foundation of China (11504350).