The object of this investigation was to determine the optimum receiver configuration to be used in an absolute, high radiation flux, calorimeter.

Three receivers of different configuration were designed, fabricated, and tested in an arc-image furnace. The results proved conclusively that the optimum receiver configuration was cylindrical with a radial entrance.

The receiver was employed in determining that the performance of the calorimeter is independent of cooling water flow rates.

The calorimeter was also used to study the flux distribution of the arc-image furnace in the Mechanical Engineering Department. The radiation flux at the optimum point of the arc-image furnace, as measured by the calorimeter, was determined to be 1.35 x 10⁶ Btu/hr-ft². Considering the area of the calorimeter aperture, this radiation flux corresponds to an equivalent blackbody temperature of 5300°K.