Free-electron laser inverse-Compton interaction x-ray source

Abstract

Free-electron lasers (FEL) and synchrotron sources of high brilliance x-rays have proven to be of tremendous value in basic and applied research. Inverse-Compton sources (ICS) can achieve brilliance matching the requirements of many applications pioneered at those FEL and synchrotron facilitiesincluding phase contrast imaging, macromolecular x-ray crystallography, and x-ray microscopy-but with size, cost, and complexity compatible with a small laboratory. The free-electron laser inverse-Compton interaction compact x-ray source at the University of Hawaii at Manoa is a unique approach to an ICS which employs an FEL as the laser source. We have measured a total average flux of 3.0 × 10 5 photons=second with an average brilliance of 2.0 × 10 7 photons=s mm 2 mrad 2 0.1% of bandwidth (BW) with a peak energy of 10.9 keV from the source. While these results are modest in comparison to the standards set by other IC sources, upgrades to the system have the potential to increase the total average flux to 9.2 × 10 11 photons=second with an average brilliance of 1.9 × 10 12 photons=s mm 2 mrad 2 0.1% BW: comparing more favorably to other sources. We discuss the scientific program, the progress made in design and development, and the achievements of the source to date. We also outline future upgrades and integration needed to yield an enabling source for emerging high brilliance x-ray applications.

A start-to-end optimisation of CLEAR for an inverse Compton scattering experiment, using RF-Track

“…The electron beam size was kept to a value lower than 10% of the beam pipe radius, except at the exit of the quadrupole doublet. This might lead to the production of secondary radiation, which can be mitigated by either scraping the electron beam with a set of collimators or installing polyethylene boards around the X-ray beamline, attenuating the secondary neutron radiation and enabling a clear path for the scattered photons [9]. A summary of the gamma-ray parameters is given in Table 1.…”

“…However, besides a significant footprint, these sources are also limited by a large emittance, which decreases the average brilliance of the scattered photon beam. Sources based on linear accelerators can offer high-quality beams for pulsed operation [8,9] in considerably smaller facility sizes. The low repetition rate of linacs can be compensated by using a burst mode-operated Fabry-Perot cavity, where Joule-level laser effective energies are stored [10].…”

Few-Cycle Infrared Pulse Evolving in FEL Oscillators and Its Application to High-Harmonic Generation for Attosecond Ultraviolet and X-ray Pulses

“…The Stanford FEL was operated at a quasi-CW mode and the external cavity worked in the steady-state mode, in which the injected pulse energy was balanced with the cavity loss. In normal-conducting-linac FELs, pulse stacking in the transient mode is suitable for maximizing the stored pulse energy [54]. In LEBRA-FEL, we will optimize the external cavity to realize FEL pulses for HHG experiments.…”