V. N. Vyuginov1, A. D. Grigoriev2

1,2 Saint-Petersburg Electrotechnical University (St.-Petersburg, Russia)

X-ray irradiation is widely used for healing cancerous tissues. Simultaneously X-ray distracts healthy tissues on their way. Electromagnetic waves of extremely high frequencies (EHF) efficiently interact with cell’s membranes if the wave frequency coincides with the resonance frequency of the membrane oscillations. Unfortunately, the small skin depth of the waves limits healing by this method to only skin and underskin organs. The EHF frequency-modulated X-rays can probably efficiently interact with cell membranes if their resonance frequency is equal to the modulation frequency. The necessary irradiation dose can be substantionally decreased in this case, and healthy tissues damage can be minor.

Analysis of the possibility of constructing an X-ray tube with EHF modulation of an electron beam. A 2-cavity klystron section, working in a self-generating regime, is used for this purpose.

The vector finite element method is used to simulate electromagnetic fields in klystron cavities. Approximate analytical methods examine electronic processes in the tube.

It is shown that a medical X-ray tube with typical parameters permits embedding in its vacuum envelope the klystron section, working in a self-oscillation regime. At accelerating voltage 15 kV and beam current 0.15 The amplification of the two-cavity section is 16 dB. Hence, feedback through the hole in the common wall can provide a self-oscillation regime of the section. Simulation of the klystron cavities and defining their form dimensions was done.

It is shown that it is possible to design an X-ray tube with modulation of radiation intensity. The modulation frequency is 35 GHz.

Resonance interaction between radiation and tissue cells increases efficiency and lowers the necessary irradiation dose, decreasing damage to healthy tissues.

Vyuginov V.N., Grigoriev A.D. An X-ray tube with extremely-high frequency intensity modulation. Nanotechnology: development and applications – XXI century. 2021 V. 13. № 4. P. 40–45. DOI: https://doi.org/10.18127/j22250980-202104-04 (in Russian)

1. Devyatkov N.D., Golant M.B., Beckij O.V. Millimetrovye volny i ih rol' v processah zhiznedeyatel'nosti. M.: Radio i svyaz'. 1991. 168 s. (in Russian).
2. Beckij O.V., Kotrovskaya T.I., Lebedeva N.N. Millimetrovye volny v biologii i medicine. Trudy III Vserossijskoj konferencii «Radiolokaciya i radiosvyaz'». IRE RAN. 2009. S. 146–150 (in Russian). 
3. Apparat spinor (CEM TECH) – chto eto? https://spinor-m.ru (in Russian).
4. Patent № 2 453 348 C2 (RU). Ustrojstvo rentgenovskogo oblucheniya patologicheskogo materiala/ O.I. Stolyarov, G.G. Bogdanov. 2009 (in Russian).
5. Grigor'ev A.D., Salimov R.V., Tihonov R.N. Modelirovanie antenn sotovyh telefonov metodom vektornyh konechnyh elementovyu // Radiotekhnika i elektronika. 2012. T. 57. № 3. S. 261–270 (in Russian).
6. Branch G.M. Jr. Electron Beam Coupling in Interaction Gaps of Cylindrical Symmetry. IRE Trans. ED. 1961. № 5. P. 193–206.
7. Grigor'ev A.D., Ivanov V.A., Molokovskij S.I. Mikrovolnovaya elektronika / Pod red. A.D. Grigor'eva. SPb.: Lan'. 2016. 496 s. (in Russian).