1. School of Nuclear Science and Technology Lanzhou University Lanzhou Gansu China
2. Engineering Research Center for Neutron Application Technology, Ministry of Education Lanzhou University Lanzhou Gansu China
3. Energy and Environment Directorate Pacific Northwest National Laboratory Richland Washington
4. Laboratório de Implantação Iônica, Instituto de Fίsica Universidade Federal do Rio Grande do Sul Porto Alegre Brazil