Fig. 1 (abstract A20).

This figure shows the distribution of the 32 spheres in the cylinder. The cylinder was 35 x 23 cm (D x L) and had a background concentration of 0.1 μCi/cc. Sixteen spheres (eight each) were organized in an octagon at radii of 7 cm and 14 cm at z = ±5.75 cm with respect to the axial center (dashed black line)