Abstract
Fine time-resolved analysis of matter—i.e., spectroscopy and photon scattering—in the linear response regime requires fs-scale pulsed, high repetition rate, fully coherent X-ray sources. A seeded Free Electron Laser (FEL) driven by a Linac based on Super Conducting cavities, generating 10 8 – 10 10 coherent photons at 2–5 keV with 0.2–1 MHz of repetition rate, can address this need. Three different seeding schemes, reaching the X-ray range, are described hereafter. The first two are multi-stage cascades upshifting the radiation frequency by a factor of 10–30 starting from a seed represented by a coherent flash of extreme ultraviolet light. This radiation can be provided either by the High Harmonic Generation of an optical laser or by an FEL Oscillator operating at 12–14 nm. The third scheme is a regenerative amplifier working with X-ray mirrors. The whole chain of the X-ray generation is here described by means of start-to-end simulations.
Highlights
Fine analyses of matter, based on techniques such as ultrafast coherent-X-ray spectroscopy, inelastic photon scattering and with applications extending from the life sciences to material physics, are currently performed with two main types of X-ray sources: synchrotron radiation (SR) sources and Free Electron Lasers (FELs) driven by linear electron accelerators (Linacs) in the self-amplified spontaneous emission (SASE) mode
We show a comparison between three different methods for producing truly coherent X-ray pulses conceived for the MariX project: (i) a harmonic cascade seeded by the harmonics of an IR laser, generated in gas; (ii) a similar cascade, but seeded by an ultraviolet
Among all the methods for producing coherent X-ray radiation, here we analyze the cascaded harmonic generation alimented by a seed obtained with High Harmonic Generation (HHG) in gases (Section 2.2) and by the radiation produced by a FEL oscillator (Section 2.3)
Summary
Fine analyses of matter, based on techniques such as ultrafast coherent-X-ray spectroscopy, inelastic photon scattering and with applications extending from the life sciences to material physics, are currently performed with two main types of X-ray sources: synchrotron radiation (SR) sources and Free Electron Lasers (FELs) driven by linear electron accelerators (Linacs) in the self-amplified spontaneous emission (SASE) mode. Successfully done at FERMI in the XUV-soft X-rays range, should be ideally extended to X-ray energies These demanding requests about pulse structure, intensity, repetition rate, reduced jitter and true coherence, able to cover the range in time resolution and average photon flux between SR and current. The FEL source MariX here described is a compact infrastructure, suitable to be constructed in medium size research centers and university campuses It is tailored for time-resolved spectroscopic applications with coherent X-rays, where the individual pulses should not exceed the linear response regime and space charge effects.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
