Term of radiation dosimetry. The quality factor was introduced to define the dose equivalent based on the fact that the probability of stochastic radiation effects not only depends on the absorbed dose but also on the radiation type. The quality factor considers the influence of the different energy distribution – which varies according to the different types of rays – in the cellular area in the irradiated body. Quality factor Q is a function of the unrestricted linear energy transfer L. The following relation has been fixed between the quality factor and the unrestricted linear energy transfer L:

Unrestricted linear energy transfer L in water, (keV µm -1)

Q (L)

L 10


10 < L < 100

0.32 L – 2.2

L 100


Relation between the linear energy transfer and the quality factors