The use of mathematical modeling underlies many of the diverse uses involving ionizing radiation. The Ionizing Radiation Division in the Physics Laboratory at the National Institute of Standards and Technology (NIST) has been a pioneer in the development of codes widely used in such modeling. These codes are used in medical, industrial and radiation-protection applications. At NIST, Monte Carlo calculations for dosimetry are cross-checked with ionizing radiation measurements. NIST graphite-wall cavity-ionization chambers serve as the national standard for air-kerma (radiation exposure). Wall corrections obtained from Monte Carlo calculations will adjust air-kerma standards world-wide by up to about 1%. Accurate measurements and calculations of absorbed dose play a significant role in industry, ensuring adequate dose in radiation processing (medical device sterilization, bioagent deactivation, etc.). In medical applications, assessing dose rate accurately is critical to effective treatment planning and fulfilling regulatory constraints.
Recognizing this broad-based use of computational methods, a Measurement Program Descriptions has been modified to express current computational needs. In this area, one MPD is presented: