All types of ionizing rays cause the same primary physical processes of ionizationAbsorption or emission of electrons by atoms or molecules, w... or excitement of atoms or molecules in the irradiated material. This is independent of whether they are of natural or artificial origin. If the radiationEnergy dispersion through matter or space. In atomic physics... exposures are indicated in sievertSpecial unit name for the organ dose and the effective dose;..., they are directly comparable, irrespective whether natural or artificial, internal or external radiationEnergy dispersion through matter or space. In atomic physics... exposure is involved.