Transmission energy spectra of 530 keV H^(+) ion penetrating 140μm thick seed coat of maize and fruit peel of grape with thickness of 100μm were measured.The result indicates that these thick biological targets,as s...Transmission energy spectra of 530 keV H^(+) ion penetrating 140μm thick seed coat of maize and fruit peel of grape with thickness of 100μm were measured.The result indicates that these thick biological targets,as seen by the penetrating ions,are inhomogeneous,and there are open“channel like”paths along which the incidentions can transmit the targets easily.While most of the incident ions are stopped in the targets,some of the transmitting ions only lose a small fraction of their initial incident energy.The transmission energy spectra show a pure electronic stopping feature.Transmission electron microscope(TEM)micrographes taken from the samples of seed coat of maize and fruit peel of tomato with thickness of 60μm indicate that 150keV electron beam from the TEM can penetrate the thick samples to give very good images with clear contrasts.展开更多
The reflection of light ions, such as H+,3He+ and 4He+, with energies of 0.1- 10 keV, from Cu and Ni surface has been studied by Monte Carlo simulation and transport theory. The Monte Carlo simulation gives the detail...The reflection of light ions, such as H+,3He+ and 4He+, with energies of 0.1- 10 keV, from Cu and Ni surface has been studied by Monte Carlo simulation and transport theory. The Monte Carlo simulation gives the detail energy spectra for the reflected particles and their angular distribution for different incident angles. It shows that the reflected particle energy spectra can be approximately described by an analytical formula for the whole energy range, all the incident angles and different ion- target combination studied here. The reflected particle energy vs its average reflection angle to the surface normal can almost be expressed by a universal curve for all cases studied here. The reflection energy spectra are used for the calculation of the reflection coefficient by transport theory including the realistic surface correction. The present work is compared with both experimental measurement and other simulation codes.展开更多
The depth profile of Br in ^(79)Br^(+) ion implanted lead-tin-telluride,Pb_(1-x)Sn_(x),was obtained by secondary ion mass spectrometry(SIMS).The SIMS profile has been compared with that obtained by our theoretical cal...The depth profile of Br in ^(79)Br^(+) ion implanted lead-tin-telluride,Pb_(1-x)Sn_(x),was obtained by secondary ion mass spectrometry(SIMS).The SIMS profile has been compared with that obtained by our theoretical calculation,in which a more realistic interatomic potential and reasonable electronic stopping power were used.The SIMS result agrees well with the theoretical calculation.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19890300in part by the Foundation for Ph.D.Education Programs from the National Education Commission of China under Grant No.96042208.
文摘Transmission energy spectra of 530 keV H^(+) ion penetrating 140μm thick seed coat of maize and fruit peel of grape with thickness of 100μm were measured.The result indicates that these thick biological targets,as seen by the penetrating ions,are inhomogeneous,and there are open“channel like”paths along which the incidentions can transmit the targets easily.While most of the incident ions are stopped in the targets,some of the transmitting ions only lose a small fraction of their initial incident energy.The transmission energy spectra show a pure electronic stopping feature.Transmission electron microscope(TEM)micrographes taken from the samples of seed coat of maize and fruit peel of tomato with thickness of 60μm indicate that 150keV electron beam from the TEM can penetrate the thick samples to give very good images with clear contrasts.
基金The Project Supported by the National Natural Science Foundation of China
文摘The reflection of light ions, such as H+,3He+ and 4He+, with energies of 0.1- 10 keV, from Cu and Ni surface has been studied by Monte Carlo simulation and transport theory. The Monte Carlo simulation gives the detail energy spectra for the reflected particles and their angular distribution for different incident angles. It shows that the reflected particle energy spectra can be approximately described by an analytical formula for the whole energy range, all the incident angles and different ion- target combination studied here. The reflected particle energy vs its average reflection angle to the surface normal can almost be expressed by a universal curve for all cases studied here. The reflection energy spectra are used for the calculation of the reflection coefficient by transport theory including the realistic surface correction. The present work is compared with both experimental measurement and other simulation codes.
基金Projects supported by the Science Fund of the Chinese Academy of Sciences。
文摘The depth profile of Br in ^(79)Br^(+) ion implanted lead-tin-telluride,Pb_(1-x)Sn_(x),was obtained by secondary ion mass spectrometry(SIMS).The SIMS profile has been compared with that obtained by our theoretical calculation,in which a more realistic interatomic potential and reasonable electronic stopping power were used.The SIMS result agrees well with the theoretical calculation.
