Generation of Soft X-Ray Radiation in a Compact Free-Electron Laser with Harmonic Multiplication
- Authors: Zhukovskii K.V.1
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Affiliations:
- Moscow State University
- Issue: Vol 64, No 3 (2019)
- Pages: 389-398
- Section: Optics
- URL: https://journals.rcsi.science/1063-7842/article/view/203106
- DOI: https://doi.org/10.1134/S1063784219030289
- ID: 203106
Cite item
Abstract
Single-pass free-electron lasers (FELs) with harmonic multiplication in the X-ray range are studied theoretically with the objective of producing intense radiation with the minimum possible FEL length, beam energy, and seed laser frequency. A cascade FEL with a two-frequency undulator for electron bunching at wavelengths of higher harmonics is proposed. The dynamics of radiation power in a FEL with harmonic multiplication cascades is investigated based on a well-proven phenomenological FEL model that covers all major losses for each harmonic in each FEL cascade. The effect of the beam quality on X-ray generation in a FEL is examined. It is demonstrated that electron beams with energy spread σe ≤ 0.0002 are required for efficient use of harmonics in a cascade X-ray FEL. The evolution of power of harmonics in several cascade FELs at wavelengths of ~2–3 nm with multiplication of seed harmonics at a wavelength of 13.51 nm (Mo/Si reflection peak) and 11.43 nm (MoRu/Be reflection peak) is studied. It is demonstrated that the power increases to ~1 GW at a FEL length up to 40 m. In addition, the operation of multicascade FELs with a seed F2 excimer 157-nm UV laser and harmonics of lasers with CO2 and C2H2 at 30 nm with a beam of electrons with an energy of ~0.6 GeV and a current of ~1 kА is studied. The power of the modeled X-ray radiation of these FELs at λ = 2.5 and 3.3 nm increases to ~0.5 GW at ~30 m.
About the authors
K. V. Zhukovskii
Moscow State University
Author for correspondence.
Email: zhukovsk@physics.msu.ru
Russian Federation, Moscow, 119991