Table 6.

Results of linear least-squares fits of percent penetration versus half-value layer in Fig. 4.

	0.30 mm Pb		0.35 mm Pb		0.40 mm Pb		0.45 mm Pb
Fit parameter1	P2	S	P	S	P	S	P	S
a	4.1379	4.0423	3.3287	3.0510	2.6795	2.3230	2.1685	1.7910
b	−6.9008	−8.2676	−6.2649	−6.5778	−5.4607	−5.1950	−4.6721	−4.1135
			0.50 mm Pb
Fit parameter1			P				S
a			1.7698				1.4015
b			−3.9705				−3.2846

¹y = ax + b.

²P = primary [Fig. 4a], S = scattered [Fig. 4b].