Generation of Cherenkov radiation in the soft x-ray region by 10-MeV electron accelerator

Ahmadi, A; Ahmadi, K; Khaleghi, Sh

Generation of Cherenkov radiation in the soft x-ray region by 10-MeV electron accelerator

Authors

A Ahmadi

K Ahmadi

Sh Khaleghi

Abstract

Cherenkov radiation is generated when relativistic charged particles move in a medium with refractive index larger than unity. Although, the refractive index is generally smaller than unity in X-ray region, in the vicinity of atomic absorption edges, the refractive index may exceed unity and Cherenkov radiation can be generated in soft X-ray region with a narrow band width. In this paper, the spectral-angular distribution of X-ray Cherenkov Radiation (XCR) and its properties are analyzed. It is shown that, by using electron accelerators which can produce 10 MeV electrons, with average current density 20 mA/mm2, and choosing different µm-thick foils, one can produce soft X-ray Cherenkov radiation source with intensity about 10-4 ph/el, and X-ray photon energy from 50 eV up to 1 keV. Some unique properties of XCR, such as narrow band width and high brightness, make XCR a novel soft X-ray source for applications in soft X-ray microscopy, photoelectron spectroscopy, analysis of trace elements and other research areas.

Keywords

electron accelerator

Cherenkov radiation

soft X-rays

1. P A Cherenkov, Phys. Rev., 52 (1937) 378.
2. G N Afanasiev, “Vavilov-Cherenkov and Synchrotron Radiation: Foundations and Applications”, Kluwer Academic Publishers, (2004) 491.
3. D T Attwood, “Soft X-rays and Extreme Ultraviolet Radiation: Principles and Applications”, Cambridge University Press, (2000), 503p.
4. V A Bazylev et al., Pisma Zh. Eksp. Teor. Fiz. 24 (1976) 406.
5. V A Bazylev et al., Sov. Phys. Usp. 25 (1982) 565.
6. W Knults et al., Appl. Phys. Lett. 83 (2004) 1050.
7. V I Vysotskii et al., J. Surf. Inves. X-ray, Synchrotron and Neutron Techniques, 7 1 (2013) 51.
8. W Knults et al., Appl. Phys. Lett. 79 (2001) 2099.
9. C T Chantler et al., http://physics.nist.gov/
10. B L Henke et al., https://henke. lbl. gov/ optical_ constants.