POSITRON ANNIHILATION STUDY ON SURFACE STRUCTURE OF BIOLOGICAL SAMPLES IMPLANTED BY IONS WITH LOW ENERGY
Lu Ting (陆挺)abc, Yu Wei-zhong (郁伟中)d, Zhou Hong-yu (周宏余)abc, Zhu Guang-hua (朱光华)abc, Wang Xin-fu (汪新福)abc, Wang Chao (王超)abc
a Key Laboratory of Beam Technology and Materials Modification of Ministry of Education, Beijing Normal University, Beijing 100875, China; b Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875, China; c Beijing Radiation Center, Beijing 100875, China; d Department of Physics, Tsinghua University, Beijing 100084, China
Abstract The organic materials of biological samples, such as lima bean and peanut, were implanted respectively by nitrogen ions with an energy of 100 keV and vanadium ions with an energy of 200 keV. The positron annihilation lifetime spectra of implanted and non-implanted samples were compared with each other especially in $\tau_3$ and I3. The experimental results showed that before implantation there were many small holes with diameters of 0.48 and 0.7 nm respectively in lima bean and peanut. After ion implantation, the size of holes would be changed because of organism cross linking and scission. The effective penetration range of implantation of ions with low energy into biological samples is about 200μm.
Received: 15 September 2000
Revised: 11 October 2000
Accepted manuscript online:
Fund: Project supported by the Giant Program of the National Natural Science Foundation of China (Grant No.19890303).
Cite this article:
Lu Ting (陆挺), Yu Wei-zhong (郁伟中), Zhou Hong-yu (周宏余), Zhu Guang-hua (朱光华), Wang Xin-fu (汪新福), Wang Chao (王超) POSITRON ANNIHILATION STUDY ON SURFACE STRUCTURE OF BIOLOGICAL SAMPLES IMPLANTED BY IONS WITH LOW ENERGY 2001 Chinese Physics 10 145
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