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.     

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.     

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.     

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.     

Determination of the 5d6p 3F4-5d2 3F transition probabilities of Ba I

Whether the transitions between 6s5d ³D and 5d6p ³F can be used for laser cooling of barium heavily depends upon the transition probabilities of 5d6p ³F-5d^{2 3}F. Taking the transition 6s5d ³D₃-5d6p ³F⁴ as a scale, the leakage rate of 5d6p ³F₄-5d^{2 3}F was used to evaluate the transition probabilities. 706 nm laser pulses with different durations were applied to a barium atomic beam for 6s5d ³D₃-5d^{2 3}F₄ optical pumping, and the remaining percentages in 6s5d ³D₃ were measured. After exponential fitting, the transition probability of 5d6p ³F₄-5d^{2 3}F_3,4 was determined to be 2.1(4)×10⁴ s^?1, which is in agreement with theoretical calculations using the scaled Thomas-Fermi-Dirac method.     

Bestimmung der Lebensdauer des 3d 9 4s 4p 4 P 3/2-Terms im Cu I-Spektrum mit optischer Doppelresonanz

The lifetime of the 3d ⁹ 4s 4p ⁴ P _3/2 state of Cu has been determined with optical double resonance by observation of radiofrequency transitions ΔF=0, Δm _F =±1 between hfs-Zeeman levels of the stable odd isotopes. The result is τ(3d ⁹ 4s 4p ⁴ P _3/2, Cu)=3.18(16)·10^?7 sec.     

Theoretical lifetimes and branching fractions of 2p4(3P)3d 4D7/2, 2F7/2 and 4F7/2 in Ne II

Transition probabilities of the radiative decay processes of the excited levels 2p⁴(³P)3d ⁴D_7/2, ²F_7/2 and ⁴F_7/2 of the fluorine-like neon ion (Ne⁺) are evaluated by variational calculations using superposition of configurations in the Breit-Pauli approximation. The strong ²F_7/2-⁴F_7/2 relativistic mixing is discussed in terms of level designation and doublet-quartet intensity transfer. A detailed comparison of the results with other theories and with the NIST measurements of branching fractions, combined with lifetime measurements, confirms problems on the experimental side.     

Eine Hyperfeinstruktur-Analyse der Grundkonfigurationen 5d 8 6s 2 und 5d 9 6s des Pt-I Spektrums

The hyperfine structure of the ground configurations 5d ⁸ 6s ² and 5d ⁹ 6s of the stable Platin isotopes 194, 195, 196, 198 was analyzed. For the isotope 195 a complete set of the magnetic splitting constantsA is given. TheA constants of the levels 5d ⁸ 6s ^{2 3} P ₁ and¹ D ₂ were determined for the first time. From these data the electronic splitting constants a_{6 s}=l010(10) mK, a_{d 3/2}=57 (6) and a_{d 5/2}=27 (2) mK could be evaluated. The effect of core polarization is discussed and a fieldκ _cp=?5.6(1.0) a.u. per 5d-electron spin is found. Also the isotopic shift is determined and for the mean quadratic nuclear charge radius the valueΒδ <r ²>=0.095 (10) fm² is derived.     

Hyperfeinstrukturanomalie und Kernquadrupolwechselwirkungskonstanten des angeregten 3d 94s 4p 4 P 3/2-Terms im Cu I-Spektram von Cu63 und Cu65

Zeitschrift für Physik A Hadrons and nuclei - The hyperfine structure of the excited 3d 9 4s 4p 4 P 3/2-term of the Cu I-spectrum was investigated in a level-crossing experiment using an...     

Hyperfeinstrukturuntersuchung der 4p und 5p 2 P 3/2-Terme im K I-Spektrum durch Resonanzstreuung von Licht zur Bestimmung der Kernquadrupolmomente von K39 und K41

In order to determine the nuclear quadrupol moments of the stable K-isotopes, the hyperfine structure of the 4p and5p ²P_3/2-states was investigated by resonance scattering of light. The scattered intensityR(H) from separated isotopes in a sealed off resonance cell, as function of an external magnetic fieldH was observed with different polarisations (σ- andπ-components perpendicular toH) both in exciting and scattered light. Because the hfs-splitting of the investigated states is comparable to the radiation widthГ, the measured change in intensityΔR(H)/ΔH is due to interference effects (Hanle-effect, level-crossing, anti-crossing) and decoupling of electronic and nuclear spin (Heydenburg-effect). The different effects are not distinguishable in contrary to an usual level-crossing experiment and therefore the measured signal-structure is compared with line shape calculations according to Breit's-formula. Assuming “white” excitation andg _J =4/3, the measured signal-structure can be explained with the following values:Γ/2π (4p)=5.7 (4) MHzΓ/2π (4p)=5.7 (4) MHz K³⁹:A(4p)=6.13(5) MHzB(4p)=2.72(12) MHzA(5p)=1.97(2) MHzB(5p)=0.85 (3) MHz K⁴¹:A(4p)=3.40(8) MHzB(4p)=3.34(24) MHzA(5p)=1.08(2) MHzB(5p)=1.06 (4) MHz. Without Sternheimer corrections one obtains from these values Q(K³⁹)=0.062 · 10^?24 cm² and Q(K⁴¹)=0.076 · 10^?24 cm² for the electrical nuclear quadrupolmoments of K³⁹ and K⁴¹.     

Lebensdauer- und Hyperfeinstrukturmessungen an einigen angeregten Zuständen der Konfiguration 4d 9 5p im Pd I-Spektrum mit der Level-crossing-Methode

Lifetimes and hfs coupling constants of some excited states of the 4d ⁹ 5p configuration of Pd I have been determined in a level crossing experiment by observing the field dependence of the polarization of the fluorescence radiation in a magnetic field. From the halfwidths of the measured zero field level crossing signals one obtains the mean lifetimes of the following fine structure states:τ(³P ₁ ⁰ )=(7.46±0.32)nsec;τ(³ P ₂ ⁰ )=(6.9±0.76)nsecτ(³P ₁ ⁰ )=(4.99±0.35)nsec;τ(³ D ₁ ⁰ )=(4.89±0.40)nsecτ((³D ₃ ⁰ )=(6.99±0.49)nsec;τ(³ F ₄ ⁰ )=(7.09±0.46)nsec.Δm=2 crossing signals were detected in the³ P ₁ ⁰ ,³D ₃ ⁰ and³F ₄ ⁰ -states of the odd isotope¹⁰⁵Pd. A detailed analysis of the experimental curves yields the hfs coupling constantsA andB of these states:A(³P ₁ ⁰ )=?(133±2) Mc/sec;B(³ P ₁ ⁰ )=(140±30) Mc/secA(³D ₃ ⁰ )=?(120±10) Mc/sec;B(³ D ₃ ⁰ )=?(660±100) Mc/secA(³F ₄ ⁰ )=?(87±2) Mc/sec;B(³ F ₄ ⁰ )=?(330±30) Mc/sec. A theoretical calculation of the hfs constants is given on the basis of reduced matrix elements. Within the limit of the errors these values agree with the experimental ones. The nuclear electric quadrupole moment deduced from the measuredB values isQ (¹⁰⁵Pd)=(0.8±0.3)·10^?24 cm² (without corrections).     

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%.     

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.     

Optische übergangswahrscheinlichkeiten der Konfigurationen 3p 5 4s–3p 5 5p des Argon I

Optical transition probabilities of the configurations 3p ⁵ 4s–3p ⁵ 5p of Argon I were determined in a wall-stabilized arc plasma and compared with the theoretical results for different types of spin-orbit-coupling. Mostly the differences in the results forLS-jl- and intermediate-coupling are small compared with the deviations of the experimental values. Therefore it may be presumed that in some cases not the assumption of an approximately valid coupling scheme is responsible for the errors of the theoretical transition probabilities, but the other quantum mechanical approximation processes.     

Level-crossing-Experiment zur Untersuchung der Hyperfeinstruktur von Au197 im5d106p2P3/2-Term

The scattering of Au-resonance line λ=2427 Å on an atomic heam was observed in external magnetic field by level crossing technic. Using the assumed interpretationB/A ? 1 for the hyperfinestructure-interaction of Au¹⁹⁷ in the²P_3/2-term a valueB ≈ll mK for the nuclear quadrupol-interaction constant is deduced.     

Lifetimes andg J factors of 6s7p and 5d6p levels of Ba I

Excited states of Ba have been investigated with optical double resonance and Hanle effect. The followingg _J factors and natural lifetimes (in 10^?9 sec) have been measured $$\begin{gathered} 6s7p\left\{ {\begin{array}{*{20}c} {^1 P_1 :g_J = 1.003(2)\tau = 13.5(6)} \\ {^3 P_1 :g_J = 1.4971(8)\tau = 85.0(8.0)} \\ \end{array} } \right. \hfill \\ 5d6p\left\{ {\begin{array}{*{20}c} {^1 P_1 :g_J = 1.004(2)\tau = 12.4(9)} \\ {^3 P_1 :g_J = 1.4847(15)\tau = 11.7(9)} \\ {^3 D_1 :g_J = 0.5064(3)\tau = 17.0(5).} \\ \end{array} } \right. \hfill \\ \end{gathered}$$ g _J is utilized to test the mixing coefficients of the wave functions in the intermediate coupling model. The lifetimes are converted into absolute transition probabilities for all the decays originating from the states investigated under the assumption that their branching ratios obtained elsewhere are correct. This assumption is not unquestionable, however.     

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.     

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.