Related papers: Tapering studies for Terawatt level X-ray FELs wit…
We study high efficiency, multi-terawatt peak power, few angstrom wavelength, X-ray Free Electron Lasers (X-ray FELs). To obtain these characteristics we consider an optimized undulator design: superconducting, helical, with short period…
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…
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…
An important goal for any advanced X-ray FEL is an option for providing Fourier-limited X-ray pulses. In this way, no monochromator is needed in the experimental hall. Self-seeding is a promising approach to significantly narrow the SASE…
Simple formulas for optimization of VUV and X-ray SASE FELs are presented. The FEL gain length and the optimal beta-function are explicitly expressed in terms of the electron beam and undulator parameters. The FEL saturation length is…
Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate…
We describe a future possible upgrade of the European XFEL consisting in the construction of an undulator beamline dedicated to life science experiments. The availability of free undulator tunnels at the European XFEL facility offers a…
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…
Multidimensional optimization schemes for TW hard X-Ray free electron lasers are applied to the cases of transversely uniform and parabolic electron beam distributions and compared to examples of transversely Gaussian beams. The…
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…
The possibility of constructing terawatt (TW) x-ray free-electron lasers (FELs) has been discussed using novel superconducting helical undulators [5]. In this paper, we consider the conditions necessary for achieving powers in excess of 1…
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 review the theory of FEL oscillators operating with tapered undulators. We consider the case of a uniform tapering and introduce a parameter which characterizes the effect of the tapering on the gain and on the saturation intensity. We…
This paper discusses the potential for enhancing the capabilities of the European FEL in the soft X-ray regime. A high longitudinal coherence will be the key to such performance upgrade. In order to reach this goal we study a very compact…
The output SASE characteristics of the baseline European XFEL, recently used in the TDRs of scientific instruments and X-ray optics, have been previously optimized assuming uniform undulators without considering the potential of undulator…
The generation of frequency-tunable, narrow-bandwidth and carrier-envelope-phase stable THz pulses with fields in the MV/cm regime that can be appropriately timed to the femtosecond X-ray pulses from free-electron-lasers is of highest…
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…
In this paper we discuss the design choices and construction strategy of the tapered undulator system designed for a high energy extraction efficiency experiment in the ultraviolet region of the electromagnetic spectrum planned for…
We demonstrate that the output radiation characteristics of the European XFEL sources at nominal operation point can be easily made significantly better than what is currently reported in the TDRs of scientific instruments and X-ray optics.…
Modern laser plasma accelerators (LPAs) often require plasma waveguides tens of cm long to propagate a high-intensity drive laser pulse. Tapering the longitudinal gas density profile in 10 cm scale gas jets could allow for single stage…