Extremely bright coherent synchrotron radiation production in a diffraction-limited storage ring using an angular dispersion-induced microbunching scheme

Generation of extremely bright, coherent synchrotron radiation in a short wavelength range is of remarkable interest in the synchrotron light source community. In this paper, a novel technique is adopted to produce coherent radiation, which uses an angular dispersion mechanism to enhance the microbunching of electrons by introducing a slight energy modulation in the long straight section of the storage ring. For this purpose, a lattice design of an extreme low emittance storage ring with 3.5 GeV energy is presented in this paper, which employs a higher-order achromat concept. We show the design results of the multibend achromat lattice with an emittance of 20 pm rad and a circumference of 900 m. Numerical simulation results demonstrate that this angular dispersion-induced microbunching scheme can be used to generate coherent radiation near the soft x-ray region, the repetition rate can reach 10 kHz, and the spectral brightness can reach 2.3×10²⁴ photons s^-1 mm^-2 mrad^-2 (0.1% bandwidth)^-1.