Gray (unit) Gray (unit) The gray (symbol: Gy) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose which measures the energy deposited in a unit mass at a certain position, and of the radiation quantity kerma, which is the amount of energy that is transferred from photons to electrons per unit mass at a certain position. The corresponding cgs unit to the gray is the rad (equivalent to
National Energy Research Scientific Computing Center National Energy Research Scientific Computing Center The National Energy Research Scientific Computing Center, or NERSC, is a high performance computing (supercomputer) user facility operated by Lawrence Berkeley National Laboratory for the United States Department of Energy Office of Science. As the mission computing center for the Office of Science, NERSC houses high performance computing and data systems used by 7,000 scientists at national laboratories and universities around the country. NERSC's newest and largest supercomputer is Cori, which was ranked 5th on the TOP500 list of world's fastest supercomputers in November 2016. NERSC is located on the main Berkeley Lab campus