Termanalyse der 4d 9 5s 5d-Konfiguration im Bogenspektrum des Silbers

The arc spectrum of silver has been remeasured in the range of 1100 to 9800 Å. This yielded some 140 new lines. Analysing these lines together with about 50 previously unidentified lines of Shenstone established 20 new levels. The configurations 4d ⁹ 5s 5p and 4d ⁹ 5s 6s are now completely analysed. In the 4d ⁹ 5s 5d-configuration about half of the expected levels were identified. Two new 4d ⁹ 5s 7s levels were found.     

Das Vorzeichen der Hyperfeinstruktur-Aufspaltung des 3d 5 4s 2 6 S 5/2-Grundzustandes des Mn55

Using a double Fabry-Perot interferometer and an atomic-beam light source, the sign of the hyperfine-structure splitting of the 3d ⁵ 4s ^{2 6} S _5/2 ground state of Mn⁵⁵ has been determined to be negative. The absolute value of the splitting previously has been measured byWoodgate andMartin.     

Stark-Effekt-Untersuchungen der Hyperfeinstruktur der 5s25d2D3/2- und 5s25d2D3/2-Terme im In I-Spektrum

The level-crossing technique with combined electric and magnetic fields was used to investigate the hyperfine structure of the 5s ²5d ² D _3/2- and 5s ²6d ² D _3/2-stedes of the In I-spectrum. From the shifts of the level-crossing signals due to the Stark effect of the electric field the Stark constantsβ of both states were deduced: 5s ²5d ² D _3/2: ¦β¦=0.33(3) Mc/(kV/cm)² 5s ²6d ² D _3/2: ¦β¦=6(1) Mc/(kV/cm)². By theoretical calculations with wave functions of the Coulomb approximation one can show, that the Stark effect in both states is mainly due to admixtures of the 5s ²6p- resp.5s ²7p-configuration.     

Stark-Effekt-Untersuchungen in der Hyperfeinstruktur der 3s 2 3d 2 D 5/2- und2 D 3/2-Terme des Al I-Spektrums

The resonance fluorescence of the transitions 3d ² D _5/2,3/2 3p ² P _3/2,1/2 in the Al I-spectrum was observed as a function of a magnetic field. Adding an electric field parallel to the magnetic field the shifts of level crossing signals caused by the Stark effect of the electric field were used to separate overlapping signals of the 3d ² D _5/2- and 3d ² D _3/2-states. The following values of the Stark parametersβ of both states and the hyperfine structure constantsA andB of the 3d ² D _3/2-states were deduced: 3d ² D _3/2∶ ¦A¦=99(1) Me/sec · g_J/0,8,B/A=?0,22(12), ¦β¦=0.45 (8) Mc/sec/(kV/cm)² · g_J,/0.8, A/β< 0 3d²D_5/2∶ ¦β¦=0.16 (4) Mc/sec/(kV/cm)² · g_J/1.2, A/β>0. Some qualitative aspects of interconfiguration mixing in the 3d²D-states are discussed.     

Lebensdauer und Hyperfeinstrukturaufspaltung der Terme 4d5s5p y2D3/2,5/2 und 4d5s5p y2F5/2,7/2 im Yttrium I Spektrum

With level crossing technique the states 4d5s5p y²D_3/2,5/2 and 4d5s5p y²F_5/2,7/2 in the Yttrium I spectrum were investigated and the magnetic hyperfine structure splitting A factors and the lifetimes determined. The experimental values are discussed and compared with theoretical results.     

Rumpfpolarisation des 4d 9 5s 22 D-Zustandes von Ag I

The hyperfine structure of the transition Ag I, 4d ⁹ 5s ²² D _3/2-4d ¹⁰5p ² P _1/2, λ=19,372 Å has been investigated by means of a photoelectrically recording Fabry-Pérot interferometer using separated isotopes. Evaluating the hfs-pattern by a digital analysis the following values for the magnetic dipole interaction constants have been obtained: $$A_{3/2}^{(109)} (d^9 5s^2 ) = - 12.11(6)mK; A_{1/2}^{(109)} (d^{10} 5p) = - 6.72(10)mK.$$ Using the knownA-factor of the other level of the configurationd ⁹ s ² and the values of the Ms anomalies of the levelsd ⁹ s ²² D _5/2 andd ¹⁰ s ² S _1/2 together with our result, the influence of the core polarization on theA-factors of the configurationd ⁹ s ² is discussed. Assuming that the used relativistic correction factors are correct, the influence of the core polarization cannot be due only to the unpaireds-electrons of the core, but must be described by the three-parameter hfs-Hamiltonian given by Harvey. Consequences for calculating the quadrupole moments from hfs data are mentioned.     

Mesure des durees de vie des niveaux de triplet des configurations (5s 7s), (5s 6d) ET (5s 7d) du cadmium

The Hanle effect has been used to measure the radiative lifetimes of the triplet states of the (5s 7s), (5s 6d), (5s 7d) configurations of cadmium.     

Experimentelle untersuchung der 5d6s6pz 2 F 5/2,7/2-Terme im Lanthan I-Spektrum unter Verwendung von Levelcrossing-Spektroskopie

The hyperfinestructure-interaction-constantsA/g _J andB/g _J of the 5d 6s6p z ² F _5/2,7/2 terms in the La I-spectrum were measured by levelcrossing technique. Using a La-atomic beam many levelcrossings between magnetic sublevels with ¦Δm¦=2 were detected in both terms by resonance scattering. Values for the lifetime of each state were deduced from the widths of Hanle-effect- and levelcrossing-signals.     

Mixing of atomic barium states 6s5d 3 D 1 and 6s5d 3 D 2 by laser radiation

Experimental studies of perturbation of atoms by laser radiation under conditions when, due to the Stark effect, the energies of two neighboring levels become equal are reported for the first time.     

Experimente und Berechnungen zur Hyperfeinstruktur der 3d 9 5g-Konfiguration im Kupfer II-Spektrum

The 3d ⁹ 5g-configuration in the Cu II-spectrum is an example for extreme(j _d l _g )K-coupling. It is shown how under these circumstances experimental hyperfinestructure separations can be explained and calculated by means of the concept of intermediate coupling between two basic coupling schemes. The basic schemes used are built on the vectorK coupled either to the spins of the outer 5g-electron or to the nuclear spinI. The value of the experimental magnetic separation factorya _j (3d) can be understood as the consequence of the core polarization of the inners-electrons by the spin of the unfilled 3d-shell. — The measured effective spin-orbit-constantζ _5g is three times larger than the theoretical result. Reasons for this discrepancy will be discussed.     

Facteurs de lande des niveaux des configurations 5s5p et 5s5d de cd I

A plane Fabry-Pérot is used to measure, with a precision of about 10^-4, the Landé factor of the levels issued from the 5s5p and 5s5d configurations of cadmium I. Calculations taking into account intermediate coupling effects and the anomalous gyromagnetic ratio of the free electron are insufficient to explain some experimental data; in such cases it is necessary to perform a more detailed analysis of the corrections due to the relativistic effects.     

Hyperfeinstruktur- und Stark-Effekt-Untersuchungen der Terme 4d5s5p z 2 F 5/2 undz 2 F 7/2 im Yttrium I Spektrum

The hyperfine structure and the Stark effect shift of the 4d5s5p z ² F _5/2 states in the Y I spectrum were investigated by level-crossing technique. Between the Zeeman effect region and the Paschen-Back region of hyperfine structure states some of the levels cross. The resonance radiation of these coherently excited levels show an interference effect of the scattering amplitudes in the crossing region. The level-crossing signals give information about hfs splitting and lifetime of the excited states under investigation. The magnetic hfs splitting factorsA of the 4d5s5p z ² F _{5/2, 7/2} states and their lifetimes were deduced. $$\begin{gathered} |A (z^2 F_{5/2} )| = (23.8 \pm 0.04) MHz \frac{{g_J }}{{0.854}} \hfill \\ |A (z^2 F_{7/2} )| = (84.08 \pm 0.01) MHz \frac{{g_J }}{{1.148}} \hfill \\ \tau (z^2 F_{5/2} ) = (46 \pm 3) 10^{ - 9} s \frac{{0.854}}{{g_J }} \hfill \\ \tau (z^2 F_{7/2} ) = (44 \pm 4) 10^{ - 9} s \frac{{1.148}}{{g_J }}. \hfill \\ \end{gathered} $$ With an electric field parallel to the magnetic field a shift of the level-crossing signals of the 4d5s5p z ² F _{5/2, 7/2} states was observed, and the Stark constants β were deduced. $$\begin{gathered} |\beta (z^2 F_{5/2} )| = (0.0020 \pm 0.0002) MHz/(kV/cm)^2 \hfill \\ |\beta (z^2 F_{7/2} )| = (0.0025 \pm 0.0015) MHz/(kV/cm)^2 . \hfill \\ \end{gathered} $$      

Level-Crossing-Experimente zur Untersuchung der Hyperfeinstruktur des 5d 2 D 5/2-Terms im Indium I-Spektrum

The resonance fluorescence of the transition 5d ² D _5/2?5p ² P _3/2 (λ=3256Å) in the In I-spectrum was observed as a function of an external magnetic field. From the level crossing signals the following values of the hyperfine constantsA andB of the 5d ² D _5/2-state were deduced: ¦A¦=148(8) Mc/sec·g _J/1.2 and ¦B/A¦≦0.3. The widths of the signals yielded the mean lifetimet=7.1 (6)·10^?9 sec · 1.2/g _J . From the shifts of the signals caused by a constant electric field parallel to the magnetic field the value of the Stark parameter ¦β¦=0.19(4) Mc/sec/(kV/cm)² ·g _J /1.2 and the sign of the ratioA/β<0 were determined. Calculations with Coulomb wave functions show that the Stark shifts of the electric field are mainly due to admixtures of the 6p ² P _3/2-state.     

Isotope shift and hyperfine structure of the transition5d6s 2 2 D 3/2-5d6s6p 4 F 3/2 of Lu175 and Lu176

Using a tunable single mode dye laser the isotope shift of the 573.7 nm-line between the isotopes Lu¹⁷⁵ and Lu¹⁷⁶ has been determined to be IS(176?175, 573.7 nm)=?394(5) MHz yielding a change of mean square nuclear radii ofδ〈r ²〉=0.022(5) fm². In addition from our measurements the following values of the hyperfine splitting constantsA andB could be deduced Lu¹⁷⁶ 5d6s6p ⁴ F _3/2:A=?651.4(0.3) MHz,B=2,494(4) MHz 5d6s ^{2 2} D _3/2:A=138.0(0.3) MHz,B=2,131(3) MHz Lu¹⁷⁵ 5d6s6p ⁴ F _3/2:A=?924.7(0.5) MHz,B=1,767(4) MHz.     

Hyperfine structure and isotope shifts in the 5d6s2 a2D3/2--5d6s(a3D)6p z4F5/2 ° transition of Hf II

The hyperfine structure and isotope shifts of the transition between the 5d6s² a²D_3/2 ground state and the 5d6s(a³D)6p z⁴F_5/2 ^° excited state of singly ionized hafnium at \lambda=340 nm have been investigated by laser spectroscopy using a radio-frequency quadrupole ion trap. The magnetic dipole coupling constant A and electric quadrupole coupling constant B of the two atomic levels for both stable isotopes ¹⁷⁷Hf and ¹⁷⁹Hf are determined. The changes of mean square nuclear charge radii \delta[ r²] of the stable Hf isotopes and the radioactive isotope ¹⁷²Hf (T_1/2=1.87a) have been extracted from the data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Anregungsraten und Zerfallsraten der ArII-4p 2 D 5 2/0 -4s2P 3/2 Niveaus und die leistungsgrenzen des 4880 Å-Lasers

Excitation and decay rates of the 4880 Å-ArII-laser transition pumped in a low-pressure arc yield a power limit for ArII high power lasers (arc diameter >1 cm), caused mainly by radiation trapping. Maximum power of the 4880 Å laser is Φ/L=70W/m±25%.