Level-crossing-Experiment zur Untersuchung des Einflusses eines elektrischen Feldes auf die Hyperfeinstruktur des 4p 2 P 3/2-Terms im Cu I-Spektrum

Level-crossing technique applying parallel electric and magnetic fields has been used to investigate the influence of an electric fieldE _z on the hyperfine structure of the 4p ² P _3/2-state. The Stark shift of the level-crossing nearH _z =155 Oe and the modification of the magnetic zero-field level-crossing signal due to the electric fieldE _z was observed. Both experimental results can be explained with a Stark-constantβ=7.2(1.1)kc(kV/cm)^?2.     

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.     

Level-crossing-Experiment am 6s6p 3 P 1-Term im Ba I-Spektrum

The hfs-splitting of the stable odd Ba-isotopes Ba¹³⁵ and Ba¹³⁷ (I=3/2) in the 6s6p ³ P ₁-state was investigated by level crossing techniques. For both isotopes two crossings between Zeeman-sublevels withδm _F=2 were detected by resonance scattering of the 7911 å-intercombination line using a Ba-atomic beam. From the experimental results ratios of zero field hfs-constants and theg _J-value of the³ P ₁-state were calculated including second order corrections. The results may be compared with double resonance measurements in zero magnetic field.     

Resonanzstreuung von Licht in magnetischen und elektrischen Feldern zur Untersuchung der Hyperfeinstruktur des 7d 2 D 3/2-Terms im Thallium I-Spektrum

Observing the resonance fluorescence of the transition 7d ² D _3/2-6p ² P _1/2 (λ=2379 Å) in the Tl I-spectrum the level crossing technique with combined electric and magnetic fields was used to investigate the hyperfine structure and the Stark effect of the 7d ² D _3/2-state. For electric field strengthsE?25 kV/cm the Stark shifts are considerably greater than the hyperfine splitting. Therefore the crossing signals for the case of decoupled hyperfine structure could be detected. The following values of the magnetic hyperfine constantA and the Stark parameterβ were deduced: ¦A¦=55(1) Mc/sec·g _J /0.8, ¦β¦=0.20(4) Mc/sec/(kV/cm)²·g _J /0.8 andA/β>0. The widths of the signals yielded the mean lifetimeτ=2.7(5)·10^?8 sec· 0.8/g _J . Sign and values ofA andβ are discussed.     

Untersuchung der Hyperfeinstruktur des 62 P 1/2-Zustandes von133Cs im starken Magnetfeld mit der optischen Doppelresonanzmethode

The hyperfine structure of the 6² P _1/2-state of¹³³Cs has been measured by optical double resonance in a strong magnetic field. From the positions of the magnetic dipole transitionsδm _J =±1,δm _I =0 theg _J -factorg _J(6² P _1/2)=0.66590(9) and the magnetic hfs-coupling constanta(6² P _1/2)=291.90(12) MHz could be derived.     

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.     

Doppelresonanzexperimente zur Untersuchung der Hyperfeinstruktur des 6s6p 3 P 1-Zustandes von171Yb und173Yb

For the odd Yb isotopes¹⁷¹Yb and¹⁷³Yb the hyperfine splitting of the 6s6p ³ P ₁ state has been measured by optical double resonance in zero magnetic field. Taking into account second order corrections due to the influence of the 6¹ P ₁ and 6³ P _0,2 states, the following results for the magnetic splitting constantA and the electric quadrupole interaction constantB have been derived: A(¹⁷¹Yb)=3958.228 (60) Mc/s, A(¹⁷³Yb)=?1094.318 (35) Mc/s, S(¹⁷³Yb)=?825.904 (85) Mc/s. The hyperfine structure anomaly of the isotopes¹⁷¹Yb and^{171 173}Yb was determined to be Δ=?0.352 (10)%.     

Level-crossing-Untersuchung der Hyperfeinstruktur des 3d 10 4p 2 P 3/2-Terms von Cu63 und Cu65

The level-crossing technic has been used to investigate the hyperfinestructur of the 3d ¹⁰ 4p ² P _3/2-term in Copper I by scattering the resonance line λ=3248 Å on an atomic beam of separated isotop Cu⁶³ respectively Cu⁶⁵ in an external magnetic field. From the level-crossing signals values for the magnetic dipol interaction constantsA and for the electric quadrupol interaction constantsB are deduced to beeA(Cu⁶³)=(194,72±0,15) Mc/secB(Cu⁶³)=?(28,8±0,6) Mc/secA(Cu⁶⁵)=(208,57±0,15) Mc/secB(Cu⁶⁵)=?(25,9±0,6) Mc/sec. With theA-value of the 3d ¹⁰ 4p²P_1/2-term from optical measurements the ratioA(² P _3/2)∶A(² P _1/2)≈0,4 is about twice greater than for an unperturbetalkali-like²P-term. From the width of the level-crossing signals a mean lifetime of the 3d¹⁰ 4p²P_3/2-term τ=(7,0±0,2) · 10^?9 sec is deduced.     

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.     

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.     

Die Hyperfeinstruktur des 32P3/2-Zustands von Natrium im starken Magnetfeld

The hyperfine structure of the 3²P_3/2 State of Na²³has been measured by the optical double resonance technique in a magnetic field of 3.1 kG sufficiently strong to decouple completelyI andJ. In the case of π or (σ⁺+σ^?) excitation the double resonance signal represents the superposition curve of eight unresolved radio-frequency transitions. The dependence of the signal on the pressure of sodium vapour and the radio-frequency field strength has been studied. The analysis of the experimental curves yields for the hyperfine coupling constants the valuesa=(18.7±0.4) Mc/s andb=(3.4±0.4) Mc/s. The nuclear electric quadrupole moment derived from the ratio ofb/a isQ=(0.146±0.02) · 10^?24cm². The Lande factor and the lifetime for the 3²P_3/2state are g_J=1.3344±0.0004 and τ=(1.61±0.07) · 10^?8 sec.     

Hyperfeinstrukturuntersuchung des 6p 2 P 3/2-Terms im Au I-Spektrum durch Resonanzstreuung von Licht

From about 6×10⁶ stoppingK ^?-meson reactions in the Saclay 80 cm hydrogen bubble chamber 70Σ ^?→Λe^?¯ν and 11Σ⁺→Λe⁺ν decays have been identified. The ratio of the vector to axial vector coupling constant has been determined,f ₁/g ₁=?0.22±0.28, consistent with the predictionf ₁=0 of the CVC-theory. The branching ratios for the two decay modes are,Γ(Σ ^?→Λe^?ν)/Γ(Σ^?→ all modes)=(0.69±0.12). 10^?4,Γ(Σ⁺→Λe⁺ν)/Γ(Σ⁺→ all modes)=(0.29±0.10). 10^?4. The ratio, Γ(Σ⁺→Λe⁺)/Γ(Σ^?→Λe^?v)=0.69±0.18, agrees with the phase space ratio, 0.61, therefore a theory that includes no second class currents is consistent with the data.     

Level-crossing-Untersuchung der Hyperfeinstruktur des angeregten 32 P 3/2- und 42 P 3/2-Zustands von Na23

The hyperfine structure of the excited 3² P _3/2- and 4² P _3/2-state of Na²³ has been investigated in a level-crossing-experiment by means of a detailed analysis of the dependence of the scattered resonance light as a function of the magnetic field. From the experimental curves the following results for the hyperfine structure constantsA andB and for the lifetimesΤ were deduced 3² P _3/2-state: 4² P _3/2-state:A=18.65(10)Mc/sA=6.006(30)g _j/1.334Mc/sB=2.82(30)Mc/sB=0.86 (9)g _j/1.334Mc/sΤ=1.60 (3) · 10^?8sΤ=6.56 (25)1.334/g_j·10^?8 s. The nuclear electric quadrupolemoment of Na²³ derived from these values isQ=0,097 · 10^?24 cm², where the Sternheimer-correction has been applied.     

Doppelresonanzuntersuchung der Hyperfeinstruktur des 52 P 3/2-Terms im K I-Spektrum zur Bestimmung des elektrischen Kernquadrupolmoments des K40

The double-resonance method has been used to measure the hyperfinestructure of the 5² P _3/2-term in the potassium I-spectrum, using a sample enriched in theK ⁴⁰ isotope. The interaction constants ofK ⁴⁰ have been determined to beA ⁴⁰=?(2.450±0.046) MHz andB ⁴⁰=?(1.31±0.33) MHz. From these the electric quadrupolmoment has been calculated to be

$$Q(K^{40} ) = - (0 \cdot 093 \pm 0 \cdot 025) \cdot 10^{ - 24} cm^2 .$$     

Die Hyperfeinstruktur des 32 P 1/2-Zustandes von Natrium im starken Magnetfeld

The hyperfine structure of the 3² P _1/2-state of²³Na has been measured by the optical double resonance technique in a magnetic field sufficiently strong to decoubleI andJ. The magnetic interaction constantA _1/2 and the Landég-factor were found to be:A _1/2=94.3(2) MHz,g=0.66581(12).     

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.     

Hyperfeinstruktur und Lebensdauer des 82 P 3/2-Terms von Rubidium

The hyperfine structure splitting of the 8² P _3/2 state of Rb⁸⁵ and Rb⁸⁷ has been investigated with optical double resonance. The following interaction constants have been obtained:A _8p ⁸⁵ =1.99(2) MHz,B _8p ⁸⁵ =1.98(12) MHzA _8p ⁸⁷ =6.75(3) MHz,B _8p ⁸⁷ =0.96(6) MHz. The lifetime of the 8² P _3/2 state is: τ=4.0(8) · 10^?7 sec.     

Die Hyperfeinstruktur des angeregten 32P3/2-Zustandes von Natrium

The hyperfine structure of the 3²P_3/2-state in the Na(I)-spektrum was investigated by optical double resonance. Three zero fieldrf-transitions (ΔF=±1, Δm_F=0) were detected and thus the unambiguous interpretation of therf-spectrum was made possible. From an analysis of therf-spectrum one obtains the magnetic hyperfine structure splitting constant a=(18.5 _?0.2 ^+0.6 ) Mc/sec the electric quadrupole interaction constantb=(3.2±0.5) Mc/sec which yields an electric quadrupole moment Q(Na²³)=(0.138±0.025)·10²⁴cm².     

Zur Hyperfeinstruktur des 62P3/2-Terms von Rb87

The hyperfine structure of the 6² P _3/2 state of Rb⁸⁷ has been reinvestigated with optical double resonance in zero magnetic field. The results for the hfs-splitting constants areA(6² P _3/2, Rb⁸⁷)=27.70 (2) Mc/s andB(6² P _3/2, Rb⁸⁷)=3.94 (4) Mc/s. From these constants one obtains a value for the nuclear quadrupole moment uncorrected for shielding effects ofQ=+0.138 (1)·10^?24 cm².     

Polarisationseffekte in der Hyperfeinstruktur von65Cu I, 3d 94s 2 m 2 D

The hyperfinestructure of the transition⁶⁵CuI, 3d ¹⁰4p ² P _3/2—3d ⁹4s ² m ² D _5/2 was investigated by optical interferometric methods. For the hfs-factors the following values were found:A(⁶⁵Cu,m ² D _5/2)=26,79(3) mK andB(⁶⁵Cu,m ² D _5/2)=5,81(10) mK. The core polarization of them ² D-terms and the Sternheimer corrections in the calculation of the quadrupolmoment of copper 65 from theB-factors of the terms 3d ⁹ 4s² m ² D and 3d ¹⁰ 4p ² P _3/2. were discussed.