Table 4.

The results of the GA for three, five, and seven-layer shields.

Shield types	Specifications	Layers
		1	2	3	4	5	6	7
Three-layers	Material	Tungsten	Lead	Tantalum
	Thickness (mm)	0.705	0.589	0.703
Five-layers	Material	Gold	Tantalum	Gold	Copper	Copper
	Thickness (mm)	0.478	0.509	0.211	0.302	0.500
Seven-layers	Material	Tantalum	Tungsten	Tantalum	Tantalum	Tungsten	Tungsten	Lead
	Thickness (mm)	0.400	0.352	0.0910	0.393	0.299	0.350	0.108