Materials

Isotopes

Weight

Fraction

Density

(g/cm³)

Zones

Material 1

(plutonium metal)

Isotope 1 (²³⁹Pu)

9.3804 × 10⁻¹

19.6

Homogeneous sphere of radius $r_1=3.794\text{cm}$ , designated as “material 1” and assigned to zone 1

Isotope 2 (²⁴⁰Pu)

5.9411 × 10⁻²

Isotope 3 (⁶⁹Ga)

1.5152 × 10⁻³

Isotope 4 (⁷¹Ga)

1.0346 × 10⁻³

Material 2

(polyethylene)

Isotope 5 (C)

8.5630 × 10⁻¹

0.95

Homogeneous spherical shell of inner radius $r_1=3.794\text{cm}$ and outer radius $r_2=7.604\text{cm}$ , designated as “material 2” and assigned to zone 2

Isotope 6 (¹H)

1.4370 × 10⁻¹