Patent ID: 7655935

Claim:
A radiation surrogate for weapons-grade plutonium, comprising in combination the radioisotopes: Ba-133 having an activity of between 5 and 5.5 μCi, Cf-252 having an activity of between about 4 and about 5 μCi, Cs-137 having an activity of between about 10.2 and about 10.4 μCi, Gd-153 having an activity of between about 350 and about 550 μCi, Lu-177m having an activity between about 40 and about 50 μCi, Sn-113 having an activity between about 13.5 and about 30 μCi, and Zr-95 having an activity between about 1 and about 6 μCi; wherein said combination of radioisotopes is substantially surrounded by tungsten foil.