Table 1.

X‐ray beam parameters used for measurements

Tube Potential	Beam Current
(kV)	(mA)	Inherent Filtration	Half‐value Layer
60	14.7	1.0 mm Al	1.3 mm Al
120	10.2	$0.5\text{mm}\text{Al}+0.10\text{mm}\text{Cu}$	4.9 mm Al
160	7.7	$1.5\text{mm}\text{Al}+0.15\text{mm}\text{Cu}$	8.0 mm Al (0.5 mm Cu)
220	12.8	$1.0\text{mm}\text{Al}+0.25\text{mm}\text{Cu}+0.45\text{mm}\text{Sn}$	2.2 mm Cu