Thesis Title
Tungsten Target Characterization and Optimization for High Specific Power X-ray Tubes
Introduction
In X-ray tubes, the target is the component hit by the high-energy electron beam, generating X-rays useful for medical, industrial, or scientific imaging. The target is usually composed of tungsten, this is due to its properties such as: high atomic number, high melting point (3422 °C), good thermal conductivity, and high density. Therefore, the characterization of targets in X-ray tubes is crucial for the life of the tube. The most crucial factors are: the composition of the target, its geometry, and the power density. This thesis aims at the characterization of the thermal properties of an X-ray tube with a tungsten-copper interface, through the development of a physical model by simulations. With the ultimate goal of optimizing such a system for a commercial tube.
Research Objectives
- Make an initial study of the state of the art regarding the topic of tungsten and tungsten/copper heat dissipation and tungsten target optimization techniques
- Physical modeling of an X-ray tube for studying the heat dissipation of the electron beam on the target and the anode
- Creation of an experimental set-up for the evaluation of temperature and their gradients
- Experimentally validate the results obtained with physical models and simulations
- Finding the optimal configuration for the target and tungsten/copper interface to be implemented on a commercial X-ray tube
- Test the feasibility of making tungsten targets through coatings
Methodology
The research activity will be based on the combination of theoretical, simulation, experimental tests and analysis tools. Advanced simulation programs (COMSOL Multiphysics, MATLAB, Geant4) will be used for the creation of a physical model useful for the study of heat dissipation in an X-ray tube. Experimental tests will be carried out to validate the reliability of the simulations. Advanced measurement and analysis equipment will be used to obtain precise information.
Expected Contributions
This thesis we expect to obtain an optimization design for heat dissipation within an X-ray tube, resulting in implementation within a commercial tube.
Preliminary Bibliography
[1] Nadella, Naresh & Khounsary, Ali. (2015). X-ray tube thermal management. 95900H. 10.1117/12.2196264. [2] Kandlakunta Praneeth, Thomas Allan, Tan Yuewen, Khan Rao, Zhang Tiezhi. Design and numerical simulations of W-diamond transmission target for distributed x-ray sources. IOP Publishing. 2019. 10.1088/2057-1976/aae55f. https://dx.doi.org/10.1088/2057-1976/aae55f. [3] Tan, Y, Chen, Q, Zhou, S, Henriksen, EA, Zhang, T. Design and optimization of thin-film tungsten (W)-diamond target for multi-pixel X-ray sources. Med Phys. 2022; 49: 5363–5373. https://doi.org/10.1002/mp.15722.