Dear Dr. Ali Afshar Farniya ,

unlike CT-based traditional sources (that are intolerant of pressures greater than 10−9 Torr, and are degraded by exposure to air), some CNT x-ray source does not require ultra-high vacuum. For example, it is also possible operated at 10−6 to 10−7 Torr for over one year without any cathode failure. These cathode can even survive exposure to full atmospheric pressure for short durations, allowing for easy repair and replacement within the housing. By contrast, a CT source would be irreparably damaged if it were exposed to even low (10−7 Torr) vacuum. For traditional source, a turbopump is sufficient to maintain vacuum; a diffusion pump or an ion pump, which are more complex and less portable, are not required.

For more details, please see the source:

-Stationary Computed Tomography for Space and other Resource-constrained Environments

Avilash Cramer, Jake Hecla, Dufan Wu, Xiaochun Lai, Tim Boers, Kai Yang, Tim Moulton, Steven Kenyon, Zaven Arzoumanian, Wolfgang Krull, Keith Gendreau, and Rajiv Gupta

Sci Rep.; 8: 14195 (2018)

Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155104/

Best regards, Pierluigi Traverso

Dear Dr. Pierluigi Traverso

Thank you very much for your attention and your time.

Best regards,

A A F