Using the longitudinal space charge instability for generation of VUV and X-ray radiation

Abstract

Longitudinal space charge (LSC) driven microbunching instability in electron beam formation systems of X-ray FELs is a recently discovered effect hampering beam instrumentation and FEL operation. The instability was observed in different facilities in infrared and visible wavelength ranges. In this paper we propose to use such an instability for generation of VUV and X-ray radiation. A typical longitudinal space charge amplifier (LSCA) consists of few amplification cascades (drift space plus chicane) with a short undulator behind the last cascade. If the amplifier starts up from the shot noise, the amplified density modulation has a wide band, on the order of unity. The bandwidth of the radiation within the central cone is given by inverse number of undulator periods. A wavelength compression could be an attractive option for LSCA since the process is broadband, and a high compression stability is not required. LSCA can be used as a cheap addition to the existing or planned short-wavelength FELs. In particular, it can produce the second color for a pump-probe experiment. It is also possible to generate attosecond pulses in the VUV and X-ray regimes. Some user experiments can profit from a relatively large bandwidth of the radiation, and this is easy to obtain in LSCA scheme. Finally, since the amplification mechanism is broadband and robust, LSCA can be an interesting alternative to self-amplified spontaneous emission free electron laser (SASE FEL) in the case of using laser-plasma accelerators as drivers of light sources.

References in corpus (3)

• SASE FEL with energy-chirped electron beam and its application for generation of attosecond pulses
• Longitudinal Wake Field for an Electron Beam Accelerated through a Ultra-High Field Gradient
• Possible operation of the European XFEL with ultra-low emittance beams

Cited by in corpus (10)

• Terawatt attosecond X-ray source driven by a plasma accelerator
• Bunch Shaping in Electron Linear Accelerators
• Generation of attosecond soft x-ray pulses in a longitudinal space charge amplifier
• High-order harmonic generation enhanced by XUV light
• Attosecond pulses at kiloelectronvolt photon energies from high-order harmonic generation with core electrons
• Cooling Rate for Microbunched Electron Cooling without Amplification
• Plasma-Cascade Instability- theory, simulations and experiment
• Micro-bunching for generating tunable narrow-band THz radiation at the FAST photoinjector
• Stimulated coherent spontaneous emission in an FEL with `quiet' bunches
• 3D Theory of Microscopic Instabilities Driven by Space-Charge Forces