Roentgen (unit) absorbed dose in a wide range of matter. When measuring absorbed dose in a human due to external exposure, the SI unit the gray, or the related non-SI rad are used. From these can be developed the dose equivalents to consider biological effects from differing radiation types and target materials. These are equivalent dose, and effective dose for which the SI unit sievert or the non-SI rem are used. The following table shows radiation quantities in SI and non-SI units: Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays
Harley A. Wilhelm Mallinckrodt, Union Carbide and DuPont began producing uranium by the Ames process, and Ames phased out its own production by early 1945. The Ames Laboratory also produced of extremely pure cerium for the cerium sulphide crucibles used by the plutonium metallurgists. Fears that world supplies of uranium were limited led to experiments with thorium, which could be irradiated to produce fissile uranium-233. A calcium reduction process was developed for thorium, and produced some . After World War II, Spedding and Wilhelm founded the Institute of Atomic Research and the Ames Laboratory of the Atomic Energy Commission. Wilhelm became its associate