Multi-electron Photoexcitation of Atoms in a Strong DC Electric Field

强直流电场中原子的多电子光激发

• 批准号: 14540384
• 负责人: AZUMA Yoshiro
• 金额: $ 2.37万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540384/
• 关键词: synchrotron radiation; radiative lifetime; many electron effects; photoexcitation; metastable atom; 多電子光励起; 強電場; シュタルク効果; 電子相関; 原子分光

Two major results were achieved during the duration of research. These include,(1) Photoion measurements of helium two electron photoexcitation in a strong electric field.(2) The achievement of "Lifetime Resolved Fluorescence Spectroscopy"The former (1) concerns multielectron photoexcitation of atoms in a strong static electric field. The project has opened virgin territory for new research on atomic structure and dynamics in a situation where the effect of electron correlation is comparable to that of the external electric field. As a matter of fact parallel developments in theory has been quick to come by, including the work on propensity rules of perturbations (Tong & Lin, Phys. Rev. Lett. 92, 223003, 2004). The implicati9ns to solid state physics, such as the behaviour of quasi-free electrons in electric fields also merit further exploration. An apparatus capable of imposing an electric field exceeding 100kV/cm has been constructed, tested at the Photon Factory, and the final measu … More rements were made at the Advanced Light Source at Berkeley, taking advantage of the high resolution and high flux available at third generation synchrotron light sources.The latter (2) result came as a new development. The strong field apparatus was originally designed only to accommodate photoion detection. Nevertheless, based mainly on the initiative of our postdoctoral fellow James Harries, implementations were made to accomplishi the detection of fluorescence and metastable atoms. This employs single-bunch operation of the synchrotron ring and makes use of the time structure of the signals to to separately detect fluorescence and meta-stable species. It was found particularly useful that the accurate determination of radiative lifetime became possible. This enabled the measurement of the two dimensional spectrum of excitation energy versus radiative lifetime "profile". The few to several lifetimes corresponding to different final ionic states can be analyzed from the 2D spectrum. This amounts to achieving the measurement of photon energy scan spectrum with constant final ionic state (Lifetime Resolved Fluorescence Spectroscopy). It is our claim that this is the third new method, with new merits and demerits in comparison to constant ionic state (CIS) electron spectroscopy, or energy analysis of fluorescence. Less

在研究期间取得了两个主要成果。其中包括：(1)强电场中氦二电子光激发的光离子测量。(2)“寿命分辨荧光光谱”的成就。前者(1)涉及原子在强静电场中的多电子光激发。在电子相关效应可与外电场效应相媲美的情况下，该项目为原子结构和动力学的新研究开辟了处女地。事实上，理论的平行发展很快就出现了，包括对扰动倾向规则的研究(Tong & Lin, Phys。Rev. Lett. 92, 223003,2004)。对固体物理的影响，如准自由电子在电场中的行为，也值得进一步探索。一个能够施加超过100kV/cm的电场的装置已经建成，在光子工厂进行了测试，并在伯克利的先进光源进行了最终测量，利用第三代同步加速器光源的高分辨率和高通量。后一种结果是一个新的发展。强场仪器最初的设计只是为了适应光子探测。然而，主要基于我们的博士后James Harries的倡议，实现了荧光和亚稳态原子的检测。该方法采用同步加速器环的单束操作，利用信号的时间结构分别检测荧光和亚稳定物质。人们发现，精确测定辐射寿命成为可能，这一点特别有用。这使得测量激发能与辐射寿命“剖面”的二维光谱成为可能。从二维光谱中可以分析出不同最终离子态对应的几个到几个寿命。这相当于在恒定的最终离子状态下实现光子能量扫描光谱的测量（寿命分辨荧光光谱）。我们认为这是第三种新方法，与恒离子态（CIS）电子能谱或荧光能量分析相比，具有新的优点和缺点。少

项目成果

Yoshiro Azuma et al.: "Double Photoexcitation of Helium in a Strong dc Electric Field"Physical Review Letters. 90 13. 133002-1-133002-4 (2003)

Yoshiro Azuma 等人：“强直流电场中氦的双重光激发”物理评论快报。

J.R.Harries, Y.Azuma, その他: "Doubly excited states of helium observed in N- and I-specific partial Photoionization cross-sections using lifetime-resolved fluorescence"Journal of Physics B. 36. L319-L326 (2003)

J.R.Harries、Y.Azuma 等人：“使用寿命分辨荧光在 N 和 I 特异性部分光电离截面中观察到氦的双激发态”物理学杂志 B. 36. L319-L326 (2003)

Double photoexcitation of helium in a strong dc electric field.

• DOI: 10.1103/physrevlett.90.133002
• 发表时间: 2003-04
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: J. Harries;J. Sullivan;J. Sternberg;S. Obara;Tadayuki Suzuki;P. Hammond;J. Bozek;N. Berrah;M. Halka;Y. Azuma

J.R.Harries, Y.Azuma, その他: "Double Photoexcitation of Helium in a Strong dc Electric Field"Physical Review Letters. 90, 13. 133002 (2003)

J.R.Harries、Y.Azuma 等人：“强直流电场中氦的双重光激发”物理评论快报。90, 13. 133002 (2003)

Double Photoeacitation of Helium in a Strong dc Electric Field

强直流电场中氦的双重光激发

• 发表时间: 2003
• 期刊: Physical Review Letters 90
• 作者: Y.Azuma;et al.
• 通讯作者: et al.