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Creation of 'Alkali-Helium' miticisle and clusters, and laser spectroscopy

“碱氦”线粒体和簇的产生以及激光光谱

基本信息

批准号：
08640506
负责人：
ISHIKAWA Kiyoshi
金额：
$ 1.47万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640506/
关键词：
Alkali metal Helium cluster Laser spectroscopy

项目摘要

The dynamics of atomic state, which is perturbed incoherently by thermal motion of surrounding particles, can be optically observed at low temperature. The information of atomic coherence is helpful to study basic concepts of quantum mechanics.Thulium atom in liquid and solid helium is studied by observing the optical transition between inner electronic shells. The metastable state is detected by trapping thulium atoms with high density in solid helium. This result makes atom in solid helium applicable to accurate measurement of atomic constants. We can also trap atoms with the technique of laser cooling. Because of high density of cooled atom, the energy or phase of optical transition is affected by the inter-atomic interactions which should be studied for accurate atomic clock. We treat O^-_ in alkali halide crystals as high density molecules, and observe the emission with high temporal and spectral resolution. Remarkable phenomena is superfluorescence from the high density O^-_ thin layr.The optical detection of atoms and molecules at low temperature is easy to change their electronic state and structure, because the energy of light is much larger than that of interaction with the surrounding atoms. In order to observe the atomic state non-destructively, we use RF field addition to laser light. High resolution magnetic resonance enable us to distinguish the kind of atoms and clusters. Three-dimensional magnetic resonance imaging(MRI)informs us the distribution of atoms at low temperature.At present we can observe the magnetic resonance and two-dimensional MRI of Cs in helium gas. Image is sensitively observed by optical pumping and detection. From the delay time from pumping to detection, we can look at diffusion of polarized Cs. In future we will measure the diffusion constants over wide temperature range, and MRI of rare gas atoms at low temperature.

在低温条件下，可以用光学方法观察到原子态受周围粒子热运动非相干扰动的动力学过程。原子相干性的信息有助于量子力学基本概念的研究，通过观察内电子层间的光学跃迁，研究了液态氦和固态氦中的氦原子相干性。亚稳态是通过在固态氦中捕获高密度的钍原子来探测的。这一结果使固体氦中的原子适用于原子常数的精确测量。我们还可以用激光冷却技术来捕获原子。由于冷原子的高密度，光跃迁的能量或相位受原子间相互作用的影响，这是精确原子钟需要研究的问题。我们把碱金属卤化物晶体中的O^-_作为高密度分子，观察到了高时间和光谱分辨率的发射。在低温下对原子和分子进行光学探测，由于光的能量远大于与周围原子相互作用的能量，因此很容易改变原子和分子的电子态和结构。为了对原子态进行非破坏性的观察，我们采用了射频场加到激光中的方法。高分辨率的磁共振使我们能够区分原子和团簇的种类。三维磁共振成像（MRI）可以告诉我们低温下原子的分布情况，目前我们可以观察到铯原子在氦气中的磁共振和二维MRI。通过光抽运和光探测，可以灵敏地观察到图像。从泵浦到探测的延迟时间，我们可以看到极化Cs的扩散。今后我们将测量宽温度范围内的扩散常数和稀有气体原子的低温磁共振成像。