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

• 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

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.

原子态的动力学受到周围粒子的热运动的非相干扰动，可以在低温下进行光学观察。原子相干性信息有助于研究量子力学的基本概念。通过观察内电子层之间的光学跃迁来研究液态氦和固态氦中的铥原子。通过将高密度铥原子捕获在固体氦中来检测亚稳态。这一结果使得固体氦中的原子适用于原子常数的精确测量。我们还可以利用激光冷却技术捕获原子。由于冷却原子的密度较高，光学跃迁的能量或相位受到原子间相互作用的影响，为了获得精确的原子钟，需要研究原子间相互作用。我们将碱金属卤化物晶体中的 O^-_ 视为高密度分子，并以高时间和光谱分辨率观察发射。显着的现象是来自高密度O^-_薄层的超荧光。低温下原子和分子的光学探测很容易改变它们的电子态和结构，因为光的能量远大于与周围相互作用的能量原子。为了无损地观察原子状态，我们将射频场添加到激光中。高分辨率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）可以让我们了解原子在低温下的分布情况。目前我们可以观察氦气中Cs的磁共振和二维MRI。通过光泵浦和检测来灵敏地观察图像。从泵浦到检测的延迟时间，我们可以观察极化铯的扩散。未来我们将测量宽温度范围内的扩散常数，以及稀有气体原子在低温下的MRI。