The Directly Irradiated Annular Pressurized Receiver (DIAPR) is a volumetric (directly-irradiated) windowed cavity receiver, designed for operation at a pressure of 10–30 bar, exit gas temperature of up to 1,300°C, and aperture radiation flux of up to 10 MW/m2. This paper presents test results obtained under various irradiation conditions and flow rates. Inlet aperture flux was up to 5 MW/m2; exit air temperatures of up to 1,200°C were obtained, while operating at pressures of 17–20 bar. Estimated receiver efficiency in these tests was in the range of 0.7–0.9. The absorber and window temperatures were 200–400°C below the permitted maximum, indicating that higher air exit temperatures are possible.