Cross-section for collisions of ultracold Li with Na

In a magneto-optical trap (MOT) we are able to simultaneously trap and cool ⁷Li and Na. We investigated the loading behavior of the cloud of Li atoms in presence of the overlapped cloud of cold Na atoms, and, by blocking the weak repumping beam for Na, compared it with the loading curve for Li atoms only. Out of these loading curves we calculated the collision cross-section of Na on Li to be 10^-11 cm ³ /s. Received 11 January 2002 / Received in final form 5 April 2002 Published online 24 September 2002     

Investigation of the hyperfine structure of TaI-lines

The hyperfine structure of several spectral lines of the neutral tantalum atom was investigated by means of saturated optogalvanic laser spectroscopy. From the spectra, we have determined the magnetic hyperfine interaction constants A and the electric quadrupole interaction constants B of 14 levels with even parity and 23 levels of odd parity.     

Modelling of emission spectra of Pr I by summarizing hyperfine patterns of overlapping spectral lines

We present studies of the the hyperfine (hf) structure of spectral lines of Praseodymium (Pr) by laser spectroscopic investigations as well as by analyzing Fourier Transform (FT) spectra. The experimental part of our work is done with the technique of laser-induced fluorescence (LIF) spectroscopy in a hollow cathode lamp. We present detailed studies of the very small region of 1.5 Å (from 5810.5 Å to 5812.0 Å) in the visible area of the FT spectrum where at least 14 spectral lines are overlapping. In the investigated region we discovered two new even levels and three new odd levels and could classify 11 new spectral lines. The final goal is to model the emission spectrum by a sum of the hf profiles of all spectral lines in a certain region. Application of such modelling may be found in analyzing highly resolved stellar spectra.     

Phase measurements of ring dark solitons

A four-frame technique for interferogram analysis is used to measure the transverse phase distribution of nonlinearly split 2D dark beams. Pairs of diametrical phase shifts within each ring are retrieved from the experiment. This result is one of the tests required to denote the formations observed as ring dark solitons.     

Hyperfine structure investigations of the tantalumI blend λ=6356.14 Å

The TaI line 6356.14 Å, up to now classified as the transition 5d ³6s ² a ⁴ P _5/2?5d ³6s(a ⁵ F)6p z ⁴ F ₇ ^2/0 , is a blend with a second transition, which is related to the additional levels 5d ⁴(b ³ G)6s a ⁴ G _9/2?39641.24 cm^?1 J=7/2°. Using laser excitation with optogalvanic and laser-induced fluorescence detection, the hyperfine constants of the four levels involved and the distance of the center wavelengths of the two fine structure transitions could be determined.     

Semiclasical model of magneto-optical trap depth

We report the results of trap depth calculations based on the semiclassical theory of interaction of light field with atom in magneto-optical trap (MOT). In our model of magneto-optical trap we take into account Zeeman shift of ground and excited states in local magnetic field and only Doppler cooling force are considered. The calculated trap depth has been compared with value of trap depth estimated from experimental results for ⁷Li.     

Zeeman- and Paschen-Back-effect of the hyperfine structure of the sodiumD 1-line

Using high-resolution laser-atomic-beam spectroscopy, Zeeman- and Paschen-Back-effects of the hyperfine structure of the sodium resonance lines were studied in fields up to app. 280 G. The results derived for theD ₁-line are given in graphical form and show clearly the change in the coupling ofJ andI of the upper level.     

The sodium D2-line in crossed electric and magnetic fields

The influence of perpendicularly crossed electric and magnetic fields on the sodium D₂-line was studied using laser-atomic-beam spectroscopy. The observed spectra show changes in the polarization type when one of the fields becomes dominant relative to the other.     

Measurement of the transition wavelengths of the lithium resonance lines

Using laser-atomic-beam spectroscopy and a highly precise lambdameter, we have determined the transition wavelengths of the lithium resonance lines to be:⁶Li D₁: 6707.0704(5)Å,⁶Li D₂: 6707.9195(5)Å;⁷Li D₁: 6707.9241(5)Å,⁷Li D₂: 6707.7723(5)Å at spectroscopic conditions (15 °C, 760 mm Hg).