Experimental studies on Feshbach-type resonances on rare gas clusters

稀有气体团簇Feshbach型共振的实验研究

• 批准号: 10640388
• 负责人: HIRAYAMA Takato
• 金额: $ 2.11万
• 依托单位: Gakushuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640388/
• 关键词: rare gas cluster; Feshbach resonance; Electron energy loss spectroscopy; excitons; 2-dimensional data acquisition system; Feshbach共鳴; 電子エネルギー損失分光法; 二次元計測システム

The purpose of this study is to confirm the existence of the Feshbach-type resonances on rare gas clusters. This resonance has been well known in rare gas atoms in gas phase, and has been found also in rare gas solids in 1993. It is not obvious whether the resonance occurs in the rare gas clusters because of its finite size.During the term of this study, we have obtained following results.・Energy levels of the 1st order surface and bulk excitons have been determined experimentally for Kr clusters with the size of 1400 atoms.・At an incident electron energy of 50eV, only the surface exciton peak has been observed, while the bulk peak appeared at incident electron energies of 100 and 200 eV.This result was explained using a mean free path (MFP) of an electron in Kr solids, i.e., the MFP of an electron with 50eV energy is comparable with the nearest neighbor distance in Kr crystal which results in higher sensitivity on the surface exciation, while MFP of 100 and 200 eV electrons is a few times longer than the nearest neighbor distance, resulting in the possibility of exciting the atoms in the bulk.・Feshbach resonances have not been observed for Kr clusters with the size of 1000 to 2000 atoms within our sensitivity of the measurements.

本研究的目的是证实稀有气体团簇上Feshbach型共振的存在。这种共振在气相中的稀有气体原子中是众所周知的，并且在1993年也在稀有气体固体中被发现。由于稀有气体团簇的尺寸有限，是否发生共振并不明显。在研究过程中，我们得到了以下结果。实验测定了1400个原子的Kr团簇的一级表面激子和体激子能级。在入射电子能量为50 eV时，仅观察到表面激子峰，而体激子峰出现在入射电子能量为100和200 eV时。50 eV电子的MFP与Kr晶体中的最近邻距离相当，这导致对表面激发的更高灵敏度，而100和200 eV电子的MFP比最近邻距离长几倍，导致激发体中原子的可能性。在我们的测量灵敏度范围内，对于1000 ~ 2000个原子的Kr团簇，没有观察到Feshbach共振。

项目成果

T.Hirayama, et al.: "Desorption of an excimer form the surface of so9lid Ne by low energy electron or photon impact"Phys.Rev.. B63. 075407 (2001)

T.Hirayama 等人：“通过低能电子或光子撞击，准分子从固体氖表面解吸”Phys.Rev.. B63。

T.Hirayama,et al.: "Desorption of an excimer from the surface of solid Ne by low energy electron and photon impact"Physical Review B. 63. 075407 (2001)

T.Hirayama 等人：“通过低能电子和光子撞击从固体氖表面解吸准分子”物理评论 B. 63. 075407 (2001)

I.Arakawa: "Absolute measurement of total photo desorption yield of solid Ne in vacuum ultraviolet range"Surf.Sci.. (in press).

I.Arakawa：“真空紫外范围内固体氖总光解吸率的绝对测量”Surf.Sci..（出版中）。