STUDY OF SOLID STATE NUCLEAR TRACK DETECTORS IN THE INSTITUTE OF ATOMIC ENERGY OF THE ACADEMY OF SCIENCES OF CHINA

Abstract

The main fields of research and achievements in the study of solid state nuclear track detectors (SSNTD) in the Institute of Atomic Energy of the Academy of Sciences of China are presented. The contents include (1) Study of parameters of SSNTDT's. A method to calibrate the detection efficiencies of SSNTD's for fission fragments by counting correlated fission fragments has been proposed and used. (2) Fast neutron spectrum and dose measurements. The threshold energy (0.3 Mev) and the detection efficiency curve of polycarbonate (PC)foil for 0.085-18 Mev neutrons by recoil tracks have been calibrated and other methods are used. (3) Studies of nuclear fission. The angular distributions of fission fragments have been studied with SSNTD's. Non-anomalous angular distributions and obvious structures have been observed near threshold energy of 238U(n, 2n'f) and 238U(n, f) reactions respectively. (4) Applications in geology, archaeology and analytic chemistry. Muscovite mica, tektites from Hainan Island in China and Peking Man have been dated by fission track method. The contents and microscopic distributions of uranium in minerals and water have been studied. (5) Meteorite study. The track densities and fission track age (3.9 ± 0.3 byr of Jilin Meteorite were measured and discussed.