(Sunday, 7/29/2018) 4:00 PM - 6:00 PM
Room: Davidson Ballroom B
Purpose: The emerging distributed x-ray sources enable new x-ray systems with improved performance. The use of stationary anode limits the power of distributed x-ray sources. The purposed of this study is to design and evaluate a tungsten-diamond transmission target for multi-pixel x-ray sources with improved focal spot power density.
Methods: A transmission target consisting of a thin layer of tungsten (W) deposited on a diamond substrate is proposed. The thickness of W in the transmission target was optimized using Geant4 Monte Carlo (MC) simulations. A transient thermal model was built in COMSOL Multiphysics finite element software. Finite element thermal simulations were performed to evaluate temperature distributions in the target under different power loadings. The maximum power that keeps the target temperature spikes under 3000°C was determined for different pulse widths. The x-ray fluence and thermal performance of the transmission target were compared to that of a traditional reflection target.
Results: A 5-6 μm W layer of the transmission target is suitable for the kVps ranged from 60-140 that are commonly used for human imaging. Results indicated that the x-ray fluence of the transmission target can be 20-30% greater than that of reflected x-rays with the same energy deposited to the target. The W-diamond transmission target is able to achieve high power operation under short pulse loadings. The W-diamond target enables as much as a four-fold higher power or 8 times higher power density than the traditional reflection target for the same temperature spikes.
Conclusion: Distributed x-ray sources with W-diamond transmission target are capable of producing higher x-ray flux and allows higher focal spot power density compared to traditional reflection targets.
Keywords
Not Applicable / None Entered.
Taxonomy
Not Applicable / None Entered.
Contact Email
