Key;
Laboratory;
of;
Ministry;
Education;
China;
for;
Radiation;
Beam;
Technology;
and;
Material;
Modification;
Institute;
Low;
Energy;
Nuclear;
Physics;
Beijing;
Center;
BeOing;
Normal;
University;
100875;
Electronic;
Science;
Tianjin;
Tianjing;
300387;
Department;
Engineering;