The backward secondary electron emission yields of MeV ions(H^(+),He^(+),He^(++),Cl,Si,and Cu)impinging on thick carbon and gold targets are studied.The measured results for H+(1MeV≤E≤5MeV)on carbon are proportional...The backward secondary electron emission yields of MeV ions(H^(+),He^(+),He^(++),Cl,Si,and Cu)impinging on thick carbon and gold targets are studied.The measured results for H+(1MeV≤E≤5MeV)on carbon are proportional to the electronic stopping power.Our experimental data and fitting formula of yields for H+(1 MeV≤E≤4.5MeV)impacting Au are compared with the theoretical expectation.The influence of the collective field and the charge state of ions on the secondary electron emission yield is discussed.展开更多
We have set up an experimental system consisting of an im gun and a Rutherford backscattering spectro-metry(RBS)analysis chamber.Using this system,in situ 2MeV*He+RBS analysis of films is carried out by combination wi...We have set up an experimental system consisting of an im gun and a Rutherford backscattering spectro-metry(RBS)analysis chamber.Using this system,in situ 2MeV*He+RBS analysis of films is carried out by combination with sputter etching cf low energy Ar+ions.As an example of the sputtering/RBS method,the analysis of three samples,i.e.,Si/(GexSi_(1-x)/Si)/Si(100),WSi_(x)/SiO_(2)/Si and CoSi_(x)/Si,is presented in this paper.After an appropriate fraction of the thick layer is removed by sputtering,the back edge of the Ge peak is separated from Si RBS spectmm on the interface and the O peak of the buried S1O2 layer can be identified.The change cf the doped Ti and W concentrations related to Co on the top surface is observed.The advantages of this analytical method and its possible applications in film are discussed.展开更多
Stopping powers of ^(7)Li ions in silicon single crystal at 1-5 MeV in random and<111>channeling directions were determined in iransmission geometry,with the uncertainties less than 6%.The measured results were ...Stopping powers of ^(7)Li ions in silicon single crystal at 1-5 MeV in random and<111>channeling directions were determined in iransmission geometry,with the uncertainties less than 6%.The measured results were compared with the available literature results and the values of TRIM-91 and TRIM-95.展开更多
文摘The backward secondary electron emission yields of MeV ions(H^(+),He^(+),He^(++),Cl,Si,and Cu)impinging on thick carbon and gold targets are studied.The measured results for H+(1MeV≤E≤5MeV)on carbon are proportional to the electronic stopping power.Our experimental data and fitting formula of yields for H+(1 MeV≤E≤4.5MeV)impacting Au are compared with the theoretical expectation.The influence of the collective field and the charge state of ions on the secondary electron emission yield is discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19874068the National High Performance Computing Fund.
文摘We have set up an experimental system consisting of an im gun and a Rutherford backscattering spectro-metry(RBS)analysis chamber.Using this system,in situ 2MeV*He+RBS analysis of films is carried out by combination with sputter etching cf low energy Ar+ions.As an example of the sputtering/RBS method,the analysis of three samples,i.e.,Si/(GexSi_(1-x)/Si)/Si(100),WSi_(x)/SiO_(2)/Si and CoSi_(x)/Si,is presented in this paper.After an appropriate fraction of the thick layer is removed by sputtering,the back edge of the Ge peak is separated from Si RBS spectmm on the interface and the O peak of the buried S1O2 layer can be identified.The change cf the doped Ti and W concentrations related to Co on the top surface is observed.The advantages of this analytical method and its possible applications in film are discussed.
文摘Stopping powers of ^(7)Li ions in silicon single crystal at 1-5 MeV in random and<111>channeling directions were determined in iransmission geometry,with the uncertainties less than 6%.The measured results were compared with the available literature results and the values of TRIM-91 and TRIM-95.
