Spallation neutron sources: Basics, state of the art, and options for future development

Fabrication of a tantalum-clad tungsten target for LANSCE

“…An alternate target material or alloy of improved properties may be selected. However, all such options bring with them so severe a penalty to the spallation yield as to render them infeasible; even a solid tantalum target, as used by the KEK Neutron Science Laboratory (KENS) in Japan for many years prior to 2000 due to its superior corrosion performance and dense atomic nucleus, will suffer over a 15% yield penalty compared to a equivalent volume of tungsten [2]. The alternative approach is to retain tungsten to occupy the vast majority of the target volume while cladding the targets with a material more resistant to corrosion.…”

Radionuclides, 2. Radioactive Elements and Artificial Radionuclides

“…The result of this process is generally an active nucleus that decays further throughg emission and b þ decay. The spallation reaction is basically endothermic [28], and it can only occur when the incident particles have energies > 100 MeV. Production of radionuclides at very large accelerators (LAMPF, BLIP) occurs by spallation.…”

Evaluation of reactivity monitoring techniques at the Yalina – Booster subcritical facility

“…There it was stated that spallation reactions are produced by high energy particles (100 MeV -10 GeV range), usually protons, impinging on heavy nuclei. The process is accompanied by the emission of a large number of light particles, neutrons among them, in a number that depends on the energy of the incident proton beam and the composition of the target [38,219]. Concerning the dependence of the neutron yields with the incident proton energy, it has been found that the number of neutrons per incident proton increases with increasing proton energy.…”