Asymmetric line shapes for medium energy H and He ions undergoing a large-angle collision
Asymmetric line shapes for medium energy H and He ions undergoing a large-angle collision
复制标题
中等能量 H 和 He 离子大角度碰撞的不对称线形
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Y. Kido
中科院分区：
文献类型：
--
作者：
M. Hazama;Y. Kitsudo;T. Nishimura;Y. Hoshino;P. L. Grande;G. Schiwietz;Y. Kido
Asymmetric line shapes for medium energy H and He ions backscattered from topmost adatoms such as $ ext{Si}(111) ext{ensuremath{-}}sqrt{3}ifmmode imeselse exttimesfi{}sqrt{3} ext{-Sb}$ and $ ext{Ni}(111) ext{ensuremath{-}}2ifmmode imeselse exttimesfi{}2 ext{-O}$ are measured by a toroidal electrostatic analyzer with an excellent energy resolution. The spectra exhibit a pronounced asymmetric nature and are well fitted by an exponentially modified Gaussian profile. It is found that the nonperturbative coupled-channel calculations reproduce well the observed asymmetric line shapes for ${ ext{He}}^{+}$ impact on different materials, although slightly overestimate the asymmetry for ${ ext{H}}^{+}$ impact on Au. On the other hand, the CASP 3.2 program (involving additional approximations) gives large underestimates for He ions and overestimates for H ions. This problem has been partially solved by modifying the order of the implementation of the shell corrections and higher-order effects in the CASP model.
Asymmetric line shapes for medium energy H and He ions backscattered from topmost adatoms such as $ ext{Si}(111) ext{ensuremath{-}}sqrt{3}ifmmode imeselse exttimesfi{}sqrt{3} ext{-Sb}$ and $ ext{Ni}(111) ext{ensuremath{-}}2ifmmode imeselse exttimesfi{}2 ext{-O}$ are measured by a toroidal electrostatic analyzer with an excellent energy resolution. The spectra exhibit a pronounced asymmetric nature and are well fitted by an exponentially modified Gaussian profile. It is found that the nonperturbative coupled-channel calculations reproduce well the observed asymmetric line shapes for ${ ext{He}}^{+}$ impact on different materials, although slightly overestimate the asymmetry for ${ ext{H}}^{+}$ impact on Au. On the other hand, the CASP 3.2 program (involving additional approximations) gives large underestimates for He ions and overestimates for H ions. This problem has been partially solved by modifying the order of the implementation of the shell corrections and higher-order effects in the CASP model.