共查询到18条相似文献,搜索用时 171 毫秒
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利用基态原子无穷长的寿命以及亚稳态原子在飞行过程中的衰减,比较由激光感应荧光法测量到的钇原子束基态和亚稳态的速度分布曲线,经过拟合处理计算,得到钇原子亚稳态a~2D_(5/2)的寿命为(0.8±0.2)ms. 相似文献
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高强度的亚稳态惰性原子束流在原子分子物理实验研究中具有广泛的应用.使用射频电离方法和激光横向冷却技术制备了高强度的亚稳态氪原子束流,并使用数值模拟方法对横向冷却激光场中的原子径迹进行了分析.通过激光诱导荧光光谱方法测量原子束的束流特性,结果显示,横向冷却后在束流源下游230 cm处的原子束流强度达1.6atoms/(s*sr),束流强度提高了两个量级.利用这种高强度原子束流,我们成功囚禁了1.3×1010个亚稳态84Kr原子,同时冷原子装载速率达到了3.0×1011atoms/s;并利用该装置成功地实现了高亮度的亚稳态氩原子束和原子阱.
关键词:
横向冷却
原子束
原子阱
惰性气体 相似文献
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共振光压作用下单一速度原子束的偏转 总被引:1,自引:1,他引:0
近年来,研究粒子在辐射场作用下的运动很受人们的重视,因为这些研究成果可用于物理学、激光光谱学和其它一些科技领域的研究工作中。本文提出利用原子束在共振光压作用下偏转的原理,获得近于单速原子束偏转的方法,并建议利用单速原子束的偏转分析原子束中速度的分布,测量原子激发态寿命和检验光子动量传递过程的统计理论。 相似文献
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耶鲁大学Amin等采用原子束-激光束交叉光谱法测量了氢和氖原子的Balmer-a跃迁(2s-3p)的波长[1].交叉束可以克服气体放电中气压和电流对测量的影响,他们精确地测量了单光子线性跃迁的波长,得到了目前最精确的里德伯常数值、玫态的精细结构分裂和氢与氚的同位素移位. 他们使用的实验装置与测量兰姆移位的装置类似.氢原子由2850K的钨炉飞出,经电子轰击至2s亚稳态,准直后散角为1.25土0.15毫弧度.一低功率的可调谐连续染料激光器产生的激光束与氢原子束成直角交叉.由原子束最后打在镍板上产生的二次电子发射来检测处于亚稳态的原子. 实验最关键… 相似文献
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通过分析铯原子在σ+-σ-组态的圆偏振光照射下塞曼子能级的分布情况,构造铯原子在二维磁光阱(2D-MOT)中的受力模型,利用龙格-库塔方法求解铯原子的运动方程,实现原子束产生过程的三维模拟。得出原子束流量随小孔半径、铯原子蒸汽压、激光光强、激光失谐量、磁场梯度等的变化规律。与实验数据进行比较表明受力模型的正确性, 该方法能直观模拟原子束的产生,准确揭示原子束流量随各项参数的变化规律,为实验提供理论指导。 相似文献
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用2660(?)的紫外激光解离PbCl_2分子时,发现在3740(?)和3734(?)波长上有较强的受激辐射输出.根据它们的光谱特性和铅原子的能级结构判断,这些辐射是基于双光子解离PbCl_2分子得到的铅原子在6p~(23)P_2亚稳能级上的布居而产生的光泵共振激光辐射和受激喇曼散射.提出了描述整个过程的理论模型,通过拟合实验结果,确定了2660(?)激光双光子解离PbCl_2产生6p~(23)P_2亚稳态铅原子的光解系数.当PbCl_2分子密度为N_(00)=6.21×10~(16)cm~(-3)时,光解产生的铅原子在6p~(23)P_2和6p~(21)D_2这两个亚稳态的最大布居数近似相等,称为2.0×10~(16)cm~(-3). 相似文献
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通过分析铯原子在σ~+-σ~-组态的圆偏振光照射下塞曼子能级的分布情况,构造铯原子在二维磁光阱(2D-MOT)中的受力模型,利用龙格-库塔方法求解铯原子的运动方程,实现原子束产生过程的三维模拟.得出原子束流量随小孔半径、铯原子蒸汽压、激光光强、激光失谐量、磁场梯度等的变化规律.与实验数据进行比较表明受力模型的正确性,该方法能直观模拟原子束的产生,准确揭示原子束流量随各项参数的变化规律,为实验提供理论指导. 相似文献
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We describe a method to generate an ultra-slow atomic beam by velocity selective resonance (VSR). A VSR experiment on a metastable helium beam in a magnetic field is presented and the results show that the transverse velocity of the deflected beam can be cooled and precisely controlled to less than the recoil velocity, depending on the magnitude of the magnetic field. We extend this idea to a cold atomic cloud to produce an ultra-slow 87Rb beam that can be used as a source of an atomic fountain clock or a space clock. 相似文献
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Greenwood JB Johnston IM McKenna P Williams ID Goodworth TR Sanderson JH Bryan WA El-Zein AA Newell WR Langley AJ Divall EJ 《Physical review letters》2002,88(23):233001
The interaction of an intense laser field with a beam of atomic ions has been investigated experimentally for the first time. The ionization dynamics of Ar+ ions and Ar neutrals in a 60 fs, 790 nm laser pulse have been compared and contrasted at intensities up to 10(16) W cm-2. Our results show that nonsequential ionization from an Ar+ target is strongly suppressed compared with that from the corresponding neutral target. We have also observed for the first time the strong field ionization of high lying target metastable levels in the Ar+ beam. 相似文献
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We have produced and characterised a slow, bright and intense atomic beam of metastable helium atoms, suitable for atomic
physics experiments. The maximum continuous flux attained was 2×1010 atoms/s, while a typical longitudinal peak velocity of the beam was ∼26 m/s with a divergence in the range of 15 mrad to
30 mrad.
PACS 32.80.Pj; 32.80.Lg; 39.10.+j 相似文献
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Shimizu F 《Physical review letters》2001,86(6):987-990
An ultracold narrow atomic beam of metastable neon in the 1s3[(2s)(5)3p:1P0] state is used to study specular reflection of atoms from a solid surface at extremely slow incident velocity. The reflectivity on a silicon (1,0,0) surface and a BK7 glass surface is measured at the normal incident velocity between 1 mm/s and 3 cm/s. The reflectivity above 30% is observed at about 1 mm/s. The observed velocity dependence is explained semiquantitatively by the quantum reflection that is caused by the attractive Casimir-van der Waals potential of the atom-surface interaction. 相似文献
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Nicolò Beverini 《Optics Communications》2009,282(13):2527-6429
We carried out theoretical investigation about velocity-selective atomic excitation on long-lived (metastable) levels of an atomic vapour in a thin cell by a monochromatic laser beam, running in the normal direction. The regime of coherent Rabi oscillations is considered on the light-induced transition from a sublevel of the ground quantum term to a metastable atomic level. On the basis of density matrix equations for the two-level system, we analysed the atomic population density of the metastable level, when the sample is irradiated by resonant monochromatic laser beam with an annular cross-section versus atomic velocities and versus the detuning, the amplitude, and the geometry of the laser beam. It is shown that, in the centre of the annular region, it can be obtained a population distribution on the metastable level as a function of the laser detuning, characterized by a sharp narrow resonance profile, whose width is reduced with respect to the thermal Doppler width roughly by the ratio between the diameter of the irradiated region and the inner thickness of the cell. We suggest high-sensitive schemes, in order to detect these sub-Doppler resonances, by probing the population of the metastable state with a second laser beam, resonant with a transition leaving from the metastable level. The case of 1S0 → 3P1 spin-forbidden transition of Ca is discussed in more detail 相似文献
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The interaction between a metastable atomic beam and a standing-wave radiation field is analyzed taking into account the effects of the natural decay between the interrogation zones and in the detection region; moreover the problem is concerned with atomic beams with cross section much wider than the radiation wavelength (multiwavelength cross section). The analysis is carried out in the density matrix formalism and numerical results obtained refer to the new frequency standards based on fine structure transitions within the Mg and Ca metastable triplets.Rabi and Ramsey techniques have been considered and the interesting figures of signal-to-background and signal-to-noise ratios, linewidth and saturation field have been evaluated assuming a Maxwellian velocity distribution and taking into account the detection process. 相似文献
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J. Kawanaka M. Hagiuda K. Shimizu F. Shimizu H. Takuma 《Applied physics. B, Lasers and optics》1993,56(1):21-24
A metastable neon (1S
5) atomic beam with a velocity of 394 m/s (373 K) and an intensity of 1.1×1015 s–1 sr–1 is produced with a novel construction using a dc glow discharge. 相似文献