Converting conventional electron accelerators to high peak brilliance Compton light sources

• Main Authors: I. V. Pogorelsky, M. Polyanskiy, T. Shaftan
• Format: Article
• Language: English
• Published: American Physical Society 2020-12-01
• Series: Physical Review Accelerators and Beams
• Online Access: http://doi.org/10.1103/PhysRevAccelBeams.23.120702

Several proposals have been put forward for converting electron accelerators to inverse Compton scattering (ICS) gamma sources. Typical approaches suggest combining near-IR solid-state lasers operating continuously at a multimegahertz repetition rate with e-beams when setting their interaction point inside a field-enhancement, Fabry-Perot optical cavity. We introduce here an alternative method of pairing particle accelerator beams with trains of long-wave-infrared, λ_{L}≈9–11  μm pulses from a picosecond CO_{2} laser of a novel architecture operating in a repetitive pulse-burst mode. Because of a considerable increase in the laser energy per pulse, combined with an order-of-magnitude higher number of laser photons per joule of laser energy, our approach allows us to increase the ICS peak flux and brilliance by 4 orders of magnitude compared to previous proposals while maintaining high (10^{11}–10^{12}  ph/s) average flux. This outcome is supported by the examples of the DAΦNE and CBETA accelerator facilities, where 10^{20}–10^{21}  ph/(s·mm^{2}·mrad^{2}·0.1%BW) peak brilliances at 50–1000 keV photon energy range can be achieved and is comparable or exceeds the capabilities of contemporary synchrotron light sources at hard x rays. Such high-brightness ICS sources will find applications in pump-probe and other ultrafast studies that require building up meaningful datasets on a single x-ray pulse.