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MO‐AB‐BRA‐08: A Modular Multi‐Source X‐Ray Tube for Novel Computed Tomography Applications
Author(s) -
Walker B,
Radtke J,
Petry G,
Swader R,
Chen G,
Eliceiri K,
Mackie T
Publication year - 2016
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4957160
Subject(s) - scanner , optics , beamline , physics , modular design , vacuum tube , beam (structure) , particle accelerator , computer science , electrical engineering , engineering , operating system
Purpose: To develop and build a practical implementation of an x‐ray line source for the rapidly increasing number of multi‐source imaging applications in CT. Methods: An innovative x‐ray tube was designed using CST Particle Studio, ANSYS, and SolidWorks. A slowly varying magnetic field is synchronized with microsecond gating of multiple thermionic electron sources. Electrostatic simulations were run to optimize the geometry of the optics and prevent electrode arcing. Magnetostatic simulations were used for beam deflection studies and solenoid design. Particle beam trajectories were explored with an emphasis on focusing, acceleration, deflection, and space charge effects. Thermal constraints were analyzed for both transient and steady‐state regimes. Electromagnetic simulations informed the design of a prototype unit under construction. Results: Particle tracking simulations for a benchtop system demonstrate that three 80 keV electron beams are able to be finely controlled and laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field in the hundreds of gauss. The beams are pulsed according to scanning sequences developed for implementation in a mock stationary CT scanner capable of a 30 ms temporal resolution. Beam spot diameters are approximately 1 mm for 30 mA beams and the stationary target stays well within thermal limits. The relevant hardware and control circuits were developed for incorporation into a physical prototype. Conclusion: A new multi‐source x‐ray tube was designed in a modular form factor to push the barriers of high‐speed CT and spur growth in emerging imaging applications. This technology can be used as the basis for a stationary high‐speed CT scanner, a system for generating a virtual fan‐beam for dose reduction, or for reducing scatter radiation in cone‐beam CT utilizing a tetrahedron beam CT geometry. A 2.4 kW benchtop system is currently being built to show proof of concept for the tube. Support for this research was provided by the University of Wisconsin Madison, Office of the Vice Chancellor for Research and Graduate Education with funding from the Wisconsin Alumni Research Foundation.