Ray-tracing model and Monte Carlo simulation for the design of the concentrating solar simulator reflector

Solar simulators are common laboratory devices to artificially reproduce the Sun emission spectrum. Their use in optic tests allows to study the effect of the solar radiation on both materials and components. This paper focuses on the effective design of the ellipsoidal reflector for concentrating solar simulators. A ray-tracing analytic model integrated to Monte Carlo simulation is proposed as an effective approach to optimize the reflector geometric configuration and to maximize the target incident radiation level and flux distribution. The developed model reproduces the ray trajectories from the source to the target and it includes the physical and optic phenomena affecting the light rays, e.g. absorption, deviation, reflection, distortion, etc. A realistic case study for the effective design of the ellipsoidal reflector for a single source small scale simulator, integrating a commercial xenon short arc lamp, is proposed to both validate and apply the proposed approach. Several scenarios are tested and the main obtained evidences are summarized.