Cooling and polarization of a sodium atomic beam by a two mode laser

Cooling and optical pumping by a circularly polarized two mode laser is applied to a Na atomic beam in transverse geometry. The low velocity components of the beam are transversly cooled to the Doppler limit temperature of 240 µK and are simultaneously spin polarized for more than 90%.     

Robust flows over time: models and complexity results

Mathematical Programming - The problem of finding a zero of the sum of two maximally monotone operators is of central importance in optimization. One successful method to find such a zero is the...     

Na-beam cooling by a mode-locked laser

Controlled mode-locked laser cooling of sodium atoms has been demonstrated for the first time. The broadband laser spectrum covers most of the Doppler-broadened atomic resonance spectrum. Atoms of a broad velocity range are thus decelerated simultaneously. In order to stop this process at a defined atomic velocity a two-mode laser beam tuned to resonance with both sodium groundstate levels is copropagating with the atomic beam and counterpropagating to the mode-locked laser beam. In this optical molasses sodium atoms ofv=20 m/s have been piled up to densities of about 2·10⁶ cm^?3. The density dependence on variable laser parameters has been investigated systematically.     

Isomer shift of the 6.2 keV nuclear transition of 181Ta in Cu3TaSe4

The isomer shift of the 6.2 keV nuclear transition of ¹⁸¹Ta in Cu₃TaSe₄ was investigated by nuclear gamma resonance spectroscopy. Relative to tantalum metal the isomer shift measured corresponds to + 32.64±0.03 mm sec^?1, which is about 17 mm sec^?1 larger than that of the isotypic Cu₃TaS₄. This is explained by the lower electronegativity of selenium as compared to sulphur.