Rational system of radiation dosimetry

Radiation doses are the most important subject to the sciences relating to the effects of ionizing radiation on matter. Since any science at all must stand on the quantitative description of causality, uses of physical quantities as the measures are indispensable. The current system of radiation dosimetry is built on the fundamental dose of the absorbed dose, which is defined as the 'energy imparted' density, and for practical convenience various weighted absorbed doses are introduced as subsidiary. However, it has been pointed out that these quantities lack adequacy inherently as a measure of causes, in addition to the insufficiency of the specification of the concept. Firstly, separation of the quantities of radiation field and of the dose is not possible, since both quantities are deeply related to the same microscopic constituents, i.e., electrons. Secondly, the value of the absorbed dose cannot be fixed at the moment of irradiation. Since the absorbed dose is a quantity of interaction product of radiation and matter, the values of the dose cannot be fixed instantaneously. Thirdly, it is not easy to envision the physical entity of the quantity from the definition. The form of existence of the 'imparted' energy is not clear in the current definition. These defects can not be removed as long as an interaction product is adopted as the dose quantity. In this paper, the authors present a prescription to solve these problems. (author)