Table 2.

Results of Genetic Algorithm for three, five, and seven-layer shields.

Shield types	Specifications	Layers
		1	2	3	4	5	6	7
Three-layers	Material	Gold	Tungsten	Aluminium
	Thickness (mm)	1.345	0.338	0.300
Five-layers	Material	Gold	Gold	Tungsten	Titanium	Titanium
	Thickness (mm)	0.205	0.851	0.729	0.190	0.010
Seven-layers	Material	Tungsten	Tantalum	Gold	Tantalum	Tungsten	Titanium	Aluminium
	Thickness (mm)	0.350	0.193	0.478	0.474	0.270	0.179	0.029