Development of Triple-Axis Spectrometer Device in HANARO: Numerical Simulation Results on Mirror-Type Collimators

The performance of Ni total-reflection combining Si-wafer collimators (RCs) was examined using a Monte Carlo simulation program. Two RCs were aligned in series to simulate diffraction measurements. The distinct total reflection component appeared in narrow regions in space and angular divergence. The diffraction intensity increased by ~40% as compared with conventional collimators. According to the simulation, the intensity gain was achieved without losing angular resolution. The reason of this promising outcome is discussed from the viewpoint of echoing and canceling out the transverse displacement, which results in spatial focusing.