3KeV H2+irradiation to Li/Pd/Cu trilaminar neutron production target for BNCT

Abstract

For the purpose of avoiding the radiation blistering of the lithium target for neutron production in BNCT (Boron Neutron Capture Therapy) device, trilaminar Li target, of which palladium thin layer was inserted between cupper substrate and Li layer, was newly designed. The Li/Pd/ Cu trilaminar structures of the synthesized target were characterized under 3 keV H2+ irradiation by XPS and XAFS technique, which provides structural/electronic properties of solids, and information about the local structure, such as the nature and number of surrounding atoms and inter-atomic distances. The following conclusions were derived; PdCu physical bonding was produced between the Pd and Cu interface by electro-less plating Pd deposition on a high purity Cu plate. From the XAFS observation of white line of Pd, the Pd L3 edge jump was found after H2+ irradiation, this fact indicates increase of hole density in Pd 4d-band. 0.9 eV chemical shift was also observed in Pd L3 white line for monolayer and 1 ?m Pd/Cu samples, which will affect the quality of the Li/Pd/Cu target due to the formation of PdHx in palladium insert layer. © 2014 The Japan Institute of Metals and Materials.