Local electrochemical deposition of thorium-229 targets and excitation of isomeric state by electron beam

Abstract

Abstract The results of the study of local formation of thin-film coatings based on thorium oxide on SiO2/Si(111) surfaces by electrochemical deposition. It is shown that as a result of electrochemical deposition of thorium atoms from an acetone solution of Th(NO3)4 with the presence of water on the silicon surface, local formation of thorium compounds occurs. Chemical analysis of the composition of the samples obtained by XPS showed the presence of compounds based on thorium, silicon, oxygen and carbon. It is shown that annealing for 6 hours at 600? C in the atmosphere leads to the departure of carbon, and the formed film consists only of thorium and oxygen. It is shown that such a system can be promising for further studies of the nuclear low-lying isomer transition in the 229Th isotope under electron beam irradiation. The method of excitation of isomeric thorium-229 nuclei by irradiation of a solid-state target based on thorium silicate with an electron beam is considered. The process of generating secondary electrons with a significant increase in the multiplication coefficient for electrons with energies in the range from 1 keV to 25 keV is considered. The values of the output function of isomeric nuclei and the excitation cross section of an isomeric transition in inelastic scattering are obtained on the basis of numerical modeling and theoretical estimation.