Neutron Production in Thick Targets Irradiated with High-Energy Ions

Figure 6

The original “two Cu disk experiments” in Berkeley showing the first evidence for unresolved problems [1, 2] in irradiations with 72 GeV ⁴⁰Ar at the Bevalac accelerator (LBNL) after 1980. 𝑅_𝑑 ratios for reaction products ^𝐴𝑍 measured in interactions of 72 GeV ⁴⁰Ar with two Cu disks are defined as: (activity of nuclide ^𝐴𝑍 downstream/activity of nuclide ^𝐴𝑍 upstream). The distance between the two Cu disks is 𝑑=0 cm for 𝑅₀ and 𝑑=20 cm for 𝑅₂₀. These ratios can be determined very accurately.