Hohlraums measuring 6 mm in diameter by 7 mm in height have been heated by x rays from a Z pinch. Over the measured x-ray input powers P of 0.7 to 13 TW, the hohlraum radiation temperature T increases from ~55 to ~130 eV, and is in agreement with the Planckian relation T~P1/4. The results suggest that indirect-drive inertial-confinement-fusion experiments involving National Ignition Facility relevant pulse shapes and <2 mm diameter capsules can be studied using this arrangement.