Apparatus for Trapping and Spectroscopy of Atoms

我们的主要目标是捕获氢(H)，氘(T)，氚(T)和锂-6和-7 （Li）的激光光谱。这些精度超过1khz的精确测量产生了同位素位移，可以用来确定核电荷半径的差异。对于氚，这将导致triton电荷半径值提高400倍。为此，我们需要冷的、被磁捕获的T原子。氢和反氢已经被捕获，并以设想的精度进行了激光光谱分析。然而，这里采用的方法不适用于氚。因此，我们计划使用被困在磁光阱（MOT）中的超密集冷Li原子云来冷却和捕获H， D和后来的T。为此，我们已经为Li建立了一个MOT装置和另一个产生H原子低温束的装置。冷锂和冷氢现在都可以使用我们现有的激光系统进行激光光谱分析。缺少的主要成分是精确测量和控制激光器的装置（频率梳）。这将使我们能够在氢原子中找到众所周知的1S-2S共振，并优化氢仪器。然后我们计划将Li装置嵌入我们的H装置中，以便能够使用冷Li气体冷却和捕获H原子。然后，我们计划在H和D中进行光谱分析，并通过与100倍更好的测量文献值进行比较，研究源自我们的陷阱和Li MOT的系统效应。最后，我们计划捕获和测量T原子，从而使triton的电荷半径提高400倍。所要求的频率梳也将用于Li MOT设备，首次使用冷锂测量Li-6/7同位素位移，获得更高的精度。最后，频率梳将帮助我们校准正在开发的用于子氢激光光谱的激光器，该激光器将产生质子磁“泽马赫”半径的100倍改进值。在我的小组中，所有这些实验的首要目标是使用光原子的激光光谱学测量最轻核的核可观测物（电荷半径，它们的差异和磁半径）。

Our main goal is the laser spectroscopy of trapped hydrogen (H), deuterium (T), tritium (T) and lithium-6 and -7 (Li). These precise measurements with an accuracy of better than 1 kHz yield the isotope shift, which can be used to determine the difference of the nuclear charge radii.For tritium, this will lead to a 400fold improved value of the triton charge radius. For this, one needs cold, magnetically trapped T atoms. Hydrogen and Antihydrogen have already been trapped, and laser spectroscopy with the envisaged precision has been performed. The methods employed there, however, can not be applied to tritium. We therefore plan to cool and trap of H, D, and later T using an ultra-dense cloud of cold Li atoms, trapped in a magneto-optical trap (MOT).To this end, we have already built a MOT setup for Li and another apparatus which produces a cryogenic beam of H atoms. Both, cold Li and cold H can now be subjected to laser spectroscopy, using our existing laser systems.The main missing ingredient is a device for precise measurement and control of our lasers (frequency comb). This will enable us to find the well-known 1S-2S resonance in atomic hydrogen, and to optimize the H apparatus. Then we plan to embed the Li apparatus into our H apparatus, to be able to cool and trap the H atoms using the cold Li gas. We then plan to perform spectroscopy in H and D and, by comparison with the 100fold better measured literature values, study the systematic effects originating from our trap and the Li MOT. Finally, we plan to trap and measure T atoms, resulting in a 400fold improved charge radius of the triton.The requested frequency comb will also used at the Li MOT apparatus to measure the Li-6/7 isotope shift using cold Li for the first time, yielding superior precision. Finally, the frequency comb will help us calibrate a laser being developed for the laser spectroscopy of muonic hydrogen which should yield a 100fold improved value of the magnetic "Zemach"-radius of the proton.The overarching goal of all of these experiments in my group are the measurements of nuclear observables (charge radii, their differences, and magnetic radii) of the lightest nuclei using laser spectroscopy of light atoms.