We present a procedure to design a facet concentrator for laboratory-scale research on medium-temperature thermal processes. The facet concentrator approximates a parabolic surface with a number of flat square facets supported by a parabolic frame and having two edges perpendicular to the concentrator axis. The optimum size and position of each facet are found by employing Monte Carlo ray tracing analysis to achieve desired flux characteristics in the focal plane. A 164-facet concentrator with realistic specularly-reflecting surface and facet positioning accuracy will deliver up to 8.15 kW of radiative power over a 15 cm radius disk located in the focal plane, with average concentration ratio exceeding 100. (C) 2012 Elsevier Ltd. All rights reserved.