Coherent Rayleigh-Brillouin scattering: influences of intermolecular potentials and chirp rates

Abstract: Chirped coherent Rayleigh-Brillouin scattering (CRBS) is a flow diagnostic technique that offers high signal-to-noise ratios and nanosecond temporal resolution. To extract information of dilute gas flow, experimental spectra must be compared with theoretical predictions derived from the Boltzmann equation. In this work, we develop a MATLAB code that deterministically solves the Boltzmann equation to compute CRBS spectra, enabling each line shape to be obtained in about one minute. We find that the CRBS spectrum is highly sensitive to the intermolecular potential, and that rapid chirping generates fine ripples around the Rayleigh peak along with spectral asymmetries.