Table 5.

DosiRat relative sensitivity for the different beam qualities

Beam quality	225 kVp 0.3 mm Cu	100 kVp 2 mm Al	40 kVp 2 mm Al
Relative sensitivity to 225 kVp 0.3 mm Cu	100%	62%	45%
Beam mean energy $\overline{E}$ (keV)	85.4	47.0	27.3
$\mathit{CF}\left(\overline{E}\right)$	0.85	0.54	0.39
Relative CF to 225 kVp 0.3 mm Cu	100%	64%	46%

Al, aluminium; Cu, copper; CF, correction factor.

Beams mean energies computed by SpekCalc²⁷ were used to calculate a CF for each beam quality. The CF is defined as the mass energy-absorption ratio between polystyrene and air.