Definition:  energy transmitted by ionizing radiation to the matter in a given volume such that: ε = R_{1} – R_{2} + ∑Q where  R_{1} is the radiant energy incident on the volume, i.e. the sum of the energies, excluding rest energies, of all those directly and indirectly ionizing particles which enter the volume,
 R_{2} is the radiant energy emerging from the volume, i.e. the sum of the energies, excluding rest energies, of all those directly and indirectly ionizing particles which leave the volume, and
 ∑Q is the sum of all changes of the rest mass energy of atomic nuclei and elementary particles in any nuclear transformations which occur in the volume; a positive sign is used when the change is a decrease and a negative sign when the change is an increase
Note 1 to entry: The energy imparted is a stochastic quantity, identical to the integral absorbed dose in that volume, and expressed in joules (J). Note 2 to entry: This entry was numbered 3931460 in IEC 60050393:2003.
