相关论文: Fel Oscillators with Tapered Undulators: Inclusion…

The problem of an efficiency increase of an FEL amplifier is now of great practical importance. Technique of undulator tapering in the post-saturation regime is used at the existing x-ray FELs LCLS and SACLA, and is planned for use at the…

We analyze the dynamics of Free Electron Laser (FEL) devices, operating with a bunched beam exhibiting a longitudinal phase space correlation. We show that the presence of an energy-position correlation term is responsible for very…

A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate…

We study the tapering optimization scheme for a short period, less than two cm, superconducting undulator, and show that it can generate 4 keV X-ray pulses with peak power in excess of 1 terawatt, using LCLS electron beam parameters. We…

High conversion efficiency between electrical and optical power is highly desirable both for high peak and high average power radiation sources. In this paper, we discuss a new mechanism based on stimulated superradiant emission in a…

In a free-electron laser equipped with variable-gap undulator modules, the technique of undulator tapering opens up the possibility to increase the radiation power beyond the initial saturation point, thus enhancing the efficiency of the…

Laser wakefield accelerators (LWFAs) are attractive compact drivers for free-electron lasers (FELs) because they can generate femtosecond electron beams with high peak current over centimeter-scale acceleration distances. However, their…

XFELs provide X-ray pulses with unprecedented peak brightness and ultrashort duration. They are usually driven by planar undulators, meaning that the output radiation is linearly polarized. For many experimental applications, however,…

We analyze the behavior of Free Electron Laser (FEL) oscillators operating in the deep saturated regime and point out the formation of sub-peaks of the optical pulse. They are very stable configurations, having a width corresponding to a…

It is reported that [Z. Huang et al., Phys. Rev. Lett. 109, 204801 (2012)], high-gain free-electron laser (FEL) can be generated by transverse-dispersed electron beams from laser-plasma accelerators (LPAs) using transverse-gradient…

Baseline design of a typical X-ray FEL undulator assumes a planar configuration which results in a linear polarization of the FEL radiation. However, many experiments at X-ray FEL user facilities would profit from using a circularly…

Recent theoretical and experimental studies have shown that Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) with a planar undulator holds a potential for generation of relatively strong coherent radiation at the third…

By utilizing higher harmonics of undulator radiation, harmonic lasing is helpful in the development of compact x-ray free electron lasers (FELs), i.e. reducing its costs and sizes. Harmonic lasing of FELs have been experimentally…

Recent progress in short wavelength free-electron lasers extending from the extreme ultraviolet through the x-ray regime have opened new avenues for industrial and research applications. A high-gain/low-Q oscillator, i.e., a regenerative…

Free-electron lasers (FELs) have been designed to operate over virtually the entire electromagnetic spectrum from microwaves through x-rays and in a variety of configurations including amplifiers and oscillators. Oscillators can operate in…

Influence of a linear energy chirp in the electron beam on a SASE FEL operation is studied analytically and numerically using 1-D model. Explicit expressions for Green's functions and for output power of a SASE FEL are obtained for…

Terawatt x-ray free-electron lasers (XFELs) require high current densities with strong transverse focusing. The implications on harmonic generation are discussed using the MINERVA simulation code which self-consistently includes harmonic…

We put forward a method to optimize the step-tapering amplitude of undulator strength and initial energy detuning of electron beam with the goal of maximizing the saturation power of high-gain FELs, based on the physics of longitudinal…

The low-gain free-electron laser (FEL) oscillators are cutting-edge tools to produce fully coherent radiation in the spectral region from terahertz to vacuum ultraviolet, and potentially in hard X-ray. In this paper, it is proposed to…

In this paper, we describe a way to automatically adjust the quadrupole focusing along the undulator to avoid the instabilities, taking into account energy change and undulator focusing. The procedure is more generalized and applicable to…