This paper describes a solar reactor in which a ceramic crucible replaces the window. The crucible is made of SiC and combines two functions: heating surface and seating partition of the reaction volume. The reactor is irradiated from top using a beam down optics. The main design issues are the sealing of the reactor and the thermal stresses created in the crucible. Careful design of the temperature profile subsequent with stress analyses, especially on the crucible, which is exposed directly to the concentrated solar radiation, and the material of construction can solve mechanical failures of the crucible. The modeling validity was verified experimentally for different operating conditions, both without reaction and with the endothermic carboreduction of ZnO. (c) 2005 Elsevier Ltd. All rights reserved.