Sr, 90 Sr / Trace determination / Environmental samples / Laser mass spectrometry SummaryA fast non-radiometric technique for ultratrace analysis of the radioisotopes 89 Sr and "°Sr in environmental samples has been developed by combining mass separation with collinear laser resonance ionization spectrometry. The efficiency and isotopic selectivity of this method allows the determination of 3X10 6 atoms of "Sr and 1 Χ 10 8 atoms of 89 Sr in the presence of 10" atoms of stable strontium, corresponding to an overall efficiency of better than 10 5 and a suppression of stable strontium of more than 10 10 . Simple and fast chemical separation procedures in combination with this technique enable the accurate determination of 89 ' 90 Sr activity in various types of environmental samples within one day, which is important in case of an emergency. The results for different environmental and technical samples, including air filters, soil, grass and milk as well as cooling water from a nuclear power station, are presented, indicating the potential and versatility of this technique.

No abstract

Abstract. Lifetimes of Rydberg states of the triplet-series 5s ns 3S 1 with n= 19-23, 35 and 5s nd 3D 3 with n= 18-20, 23-28 in the spectrum of neutral strontium have been determined. Observation of the exponential decay after excitation by a pulsed laser in a fast atomic beam and subsequent state-selective field ionization was employed. The lifetimes of the states of the 3Sl-series show the expected n* 3 dependence on the effective principal quantum number, while the 3D3-series is disturbed by configuration mixing. Furthermore, state re-populations induced by black-body radiation have been observed.

High-resolution state-selected ion-molecule reaction studies using pulsed field ionization photoelectronsecondary ion coincidence method Rev. Sci. Instrum. 74, 4096 (2003); 10.1063/1.1599071Selective field ionization of high Rydberg states: Application to zero-kinetic-energy photoelectron spectroscopy Dissociation of stateselected complex ions studied by massselective pulsed field threshold ionization spectroscopy J. Chem. Phys. 97, 5923 (1992); 10.1063/1.463754The first ionization potential of zirconium atoms determined by two laser, fieldionization spectroscopy of high lying Rydberg series

Abstract. The hyperfine spectra of the 5s4d3D~-5s20f, 5s4d3D2-5s23f and 5s4d3D3-5s32f transitions of 87Sr (I = 9/2) have been measured by collinear fast beam laser spectroscopy. The structure in the upper configurations is highly perturbed by fine structure splitting that is of comparable size to the hyperfine interaction energy. These perturbations can be adequately treated with conventional matrix diagonalization methods, using the 5 selectron magnetic dipole interaction term as~ and the unperturbed fine structure splittings as input parameters. Additionally, hyperfine constants for the lower 5s4d3D configurations, including the A-and B-factors and a separation of the individual s-and d-electron contributions to these factors, are derived.