The production of radioisotopes for medical applications by the adiabatic resonance crossing (ARC) technique

The Transmutation by Adiabatic Resonance Crossing (TARC) technique has been proposed by Rubbia (Resonance enhanced neutron captures for element activation and waste transmutation, CERN-LHC/97-0040EET, 1997; TARC collaboration, Neutron-driven nuclear transmutation by adiabatic resonance crossing, CERN-SL-99-036EET, 1999; Abanades et al., Nucl. Instr. and Meth. A 487 (2002) 577) for element activation and waste transmutation. We investigate the possibility to use this technique for the industrial production of Mo-99 and Xe-125 by resonance neutron capture in Mo-98 and Xe-124, respectively. Their daughters, i.e. Tc-99m and I-125, are widely used in medical applications. The high neutron flux needed is produced by bombarding a thick Be target with 65 or 75 MeV proton beam (few microamperes). This target is placed at the centre of a large cubic lead assembly (1.6m side, purity: 99.999%). The neutrons are progressively slowed down by elastic scattering on lead, and their energies "scan" the region where neutron resonances occur (in the eV range). Samples are properly located in the lead assembly where the resonance neutron capture probability is maximised. This paper presents the very promising results obtained by activation of metallic Mo-nat foils and Xe-nat. The results obtained on Au, In and W samples are also presented. These samples have been used to calculate the neutron fluence at various positions in the lead assembly. (C) 2002 Elsevier Science B.V. All rights reserved.