1. Looking Inside a Prototype Compact X-Ray Tube Comprising CNT-Based Cold Cathode and Transmission-Type Anode
- Author
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Hyoung-Koo Lee, Carlos Henry Castano Giraldo, David Pommerenke, Wesley Tucker, and Ashish V. Avachat
- Subjects
Radiation ,Materials science ,Nanotubes, Carbon ,business.industry ,X-Rays ,Biophysics ,Equipment Design ,X-ray tube ,030218 nuclear medicine & medical imaging ,Anode ,law.invention ,03 medical and health sciences ,Field electron emission ,0302 clinical medicine ,law ,030220 oncology & carcinogenesis ,Cathode ray ,Cold cathode ,Optoelectronics ,Radiology, Nuclear Medicine and imaging ,Focal Spot Size ,Electric current ,business ,Electrodes ,Electrostatic lens - Abstract
In this article, we offer a look inside our prototype compact X-ray tube by reporting on our findings when we experimentally studied it. We studied the prototype experimentally to characterize its primary components, i.e., carbon nanotube (CNT)-based cold cathode, electrostatic lens and transmission-type anode, and to validate our previous simulation studies. We characterized the CNT-based cold cathode by studying the relationship between the electron emission current and its control parameter, electron extraction voltage. This relationship, commonly known as the current-voltage characteristic, showed an exponential-like nature that is expected from the Fowler-Nordheim model for field emission. Next, we characterized the electrostatic lens by studying the effects of lens voltage on the focal spot size. Their relationship showed a "V" trend and corroborated that we can control the focal spot size by controlling the lens voltage. We then characterized the transmission-type anode of the prototype by studying its output X-ray energy spectra at different anode voltages. We could control the highest and the mean X-ray energies generated from the transmission-type anode using the anode voltage. For the same anode voltage and aluminum filtration, when we compared the Xray energy spectrum generated from the transmission-type anode with that of the conventional reflection-type anode, we observed that the two energy spectra agreed with each other.
- Published
- 2020