Strontium optical lattice clocks for practical realization of the metre and secondary representation of the second

We present a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. The absolute frequency of the clocks can be verified by the use of Er:fiber optical frequency comb with the GPS-disciplined Rb frequency standard. We report hertz-level spectroscopy of the clock line and measurements of frequency stability of the two strontium optical lattice clocks.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Meas. Sci. Technol. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/0957-0233/26/7/07520

On Argon-Induced Pressure Shifts of 198\text{}^{198}Hg Spectral Lines Associated with Quasi-Rydberg Transitions

The extended Omont-Kaulakys-Ueda treatment of collisional effects on quasi-Rydberg states, in which the perturbation of the lower state is taken into account, is applied to mercury-argon system. The pressure shift coefficients of 6p-ns and 6p-nd spectral lines are calculated and compared with available experimental data

Differential Equation for Asymmetric Voigt Profile

The second-order differential equation for the asymmetric Voigt profile is presented, leading to a powerful and accurate method of determining the line shape parameters

Pressure broadening of hyperfine-structure components of the 5

Experimental results of a spectroscopic study of argon broadened profiles of the hyperfine-structure components of the intercombination 326.1 nm line 113Cd isotope are reported. We have found that the values of Lorentzian (collisional) widths of both hfs line components are different

Collision-Time Asymmetry and Speed-Dependent Effects on the 114\text{}^{114}Cd 326.1 nm Line Perturbed by Kr

Using a laser-induced fluorescence method, detailed analysis of profiles of the $\text{}^{114}$Cd 326.1 nm line perturbed by krypton was performed which revealed departures from the ordinary Voigt profile. These departures are shown to be consistent with fits of experimental profiles to a speed-dependent asymmetric Voigt profile. Coefficients of the pressure broadening, shift, and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation for the van der Waals, Czuchaj-Stoll, and Morse potentials

Collision-time asymmetry of the

Using a laser-induced fluorescence method a detailed analysis of profiles of the 114Cd 326.1 nm line perturbed by argon was performed which revealed deviations from the ordinary Voigt profile. These deviations are shown to be consistent with fits of experimental profiles to an asymmetric Voigt profile. Coefficients of the pressure broadening, shift and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation for different interaction potentials

Collision-Time Asymmetry and Speed-Dependent Effects on the 114

Using a laser-induced fluorescence method, detailed analysis of profiles of the $\text{}^{114}$Cd 326.1 nm line perturbed by krypton was performed which revealed departures from the ordinary Voigt profile. These departures are shown to be consistent with fits of experimental profiles to a speed-dependent asymmetric Voigt profile. Coefficients of the pressure broadening, shift, and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation for the van der Waals, Czuchaj-Stoll, and Morse potentials

Influence of the line-shape model on the spectroscopic determination of the Boltzmann constant

International audienc

INFLUENCE OF EXCITATION PROCESSES . ON THE SHAPE OF ARGON AND NEON LINES

Shapes of self-broadened argon lines 687.1 nm (4d5-2p10), 703.0 nm (3s5 -2p9 ), 750.3 nm (2p1-1S2) as well as the neon line 748.8 nm (3d3-2p10) emitted from glow discharges at low pressures were analysed using a FabryPerot interferometer. We showed that the dissociative recombination of Are (or Ν ) molecular ions which gives rise to the density of non-thermalized atoms, may be regarded as the main process responsible for the distortion of the profiles of the above lines. The distorted profiles were analysed as superposition of the Ballik profile for thermalized atoms and the modified Ballik profile for non-thermalized atoms. The Lorentzian and Gaussian widths as well as relative densities of non-thermalized and thermalized atoms were . determined