E. Stachowska

Construction of energy matrix for complex atoms in space of (nd + n's)N + 2 + Σi,j ndN + 2 − wi − wjniliwinjljwj (where wi + wj ⩽ 2) configurations

A method of parametrization of interactions in the fine-structure of 3d-atoms is extended to the model space of configurations (nd + ns)N + 2 + Σi,j ndN + 2 − wi − wjniliwinjljwj. It accounts for the first- as well as the second-order effects of the perturbation theory. The close analogy to the parametrization of the hyperfine structure interactions is shortly discussed, this can serve as a sensitive test for the quality of fine structure analysis.

Experimental and theoretical challenges for the trapped electron quantum computer

We discuss quantum information processing with trapped electrons. After recalling the operation principle of planar Penning traps, we sketch the experimental conditions to load, cool and detect single electrons. Here we present a detailed investigation of a scalable scheme including feasibility studies and the analysis of all important elements, relevant for the experimental stage. On the theoretical side, we discuss different methods to couple electron qubits. We estimate the relevant qubit coherence times and draw implications for the experimental setting. A critical assessment of quantum information processing with trapped electrons concludes the paper.

High precision investigations of the hyperfine structure of metastable levels in a chromium atom

A series of precise measurements of the hyperfine structure (hfs) of nine metastable levels in a chromium atom 53Cr has been performed. For eight levels the hfs has been investigated with the method of laser induced fluorescence (LIF) on an atomic beam, and for the lowest-lying metastable level 3d54s 5S2 a still more precise method of laser-rf double resonance on an atomic beam (ABMR-LIRF) has been applied. A semi-empirical analysis of the fine and the hyperfine structure of the chromium atom, including many-body interaction effects, has been carried out in order to determine the value of the nuclear electric quadrupole moment, which amounts to Q = −0.22(1) barn.

Recent progress in the theory of the complex atomic hyperfine structure

The revised analysis of the hyperfine structure of the complex atoms on several selected examples has been performed. The complete set of corrections up to the second order perturbation theory has been taken into account and the accuracy of the wave functions in the intermediate coupling scheme has been carefully checked. The still remaining discrepancies suggest that the commonly used approximate model of the hyperfine structure might require revision.

Experimental investigation of the stability diagram for Paul traps in the case of praseodymium ions

The present paper describes an investigation of non-linear resonances of praseodymium ion clouds stored in a Paul trap as a function of the storage parameters. These have been observed in traps with different ring electrode diameters. In these different traps the resonances occur for different values of the operating parameters. Discrepancies with the approximation model for one ion have been found. The intensity of the fluorescence signal and the Doppler half width have been recorded as a function of one of the storage parameters: q. We use our results to optimize the fluorescence signal of the stored ions, which is especially useful in the case of the double-resonance method.

Human Sperm Morphology Analysis using a Digital Holographic Microscope

We used a digital holographic microscope (DHM) to analyse human sperm morphology. Length, width and thickness of the sperm cell head were determined by an operator, using the images produced by the software provided with the DHM. We developed an algorithm to replace part of the activities of the operator. This algorithm was written in the programming language R and the package EBImage. The algorithm produced similar results, while reducing the time needed from six hours to two when using a standard procedure.

On the level system of Bi II

The spectrum of Bi II was remeasured in the wavelength range 620?74?nm, using different hollow cathode light sources, resulting in 91 new classified lines. We found two even and eight odd new levels. Fine and hyperfine structure analysis has been performed with a many configurations approach. We determined for all levels the Land? gJ-factors and the hfs A-constants, using the wavefunctions calculated. For the first time, radial hyperfine structure parameters were determined for the excited configurations 6s26pnl (l = s, p, d, f, g). We will also discuss the important role of configuration interaction effects on fine and hyperfine structures.

The application of laser spectroscopy to investigations of praseodymium and neodymium

Recent investigations of neodymium and praseodymium using high resolution spectroscopy of atoms and ions in a hollow cathode and a Paul trap have produced new results. Some selected aspects of these experimental methods will be discussed.

Nonlinear resonances in a quadrupole ion trap by laser induced fluorescence

Nonlinear resonances in a quadrupole trap using laser induced fluorescence (LIF) were studied in Nd and Pr for the first time. Two type ofresonances have been recorded : pure coupling resonances and resonances along the trap axis. The relevant parameters of these resonances have been determined.

Observation of space charge effects in dynamics of trapped ions

In the present work an effect of space charge in a Paul trap has been observed for selected rare earth elements as a shift of secular frequency of ion motion. For Pr+ ions influence of relative number of stored ions on the value of the shift has been examined and initial estimates of the number of ions are given.