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.     

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.     

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.     

Die Hyperfeinstruktur des 6s 6p 3 P 1-Zustandes von171Yb und173Yb

The hyperfine structure of the 6s 6p ³ P ₁ state of¹⁷¹Yb and¹⁷³Yb has been investigated by the level crossing technique and by optical double resonance. The following results for the magnetic hfs splitting constantA and for the electric quadrupole interaction constantB have been obtained:A(¹⁷¹Yb)=3959.1(14)Mc/sec;A(¹⁷³Yb)=?1094.7(6) Mc/sec;B(¹⁷³Yb)=?826.9(9) Mc/sec. The hyperfine structure anomaly of the isotopes¹⁷¹Yb and¹⁷³Yb was determined to beΔ=?0.36(3)%.     

Berechnung der Signalform bei Doppelresonanzexperimenten an2 P 3/2-Zuständen im starken Magnetfeld

A computer program has been set up, which permits to calculate the signal shape for optical double resonance experiments in² P _3/2-states of alkali atoms in a strong magnetic field. The application to the 5² P _3/2-state of³⁹K, where recently large discrepancies have been reported between early double resonance measurements and new level crossing experiments, has the following results:

1. The measured strong field spectra can be reproduced satisfactorily, if the level crossing data for the hyperfine structure coupling constants are used.
2. The computed line shifts are in good agreement with a formula recently deduced by means of a new approximation methode.

     

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.     

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)%.     

Zur Rumpfpolarisation des Rb-Atoms: Hyperfeinstruktur des 72 P 1/2-Terms von Rb85

The hyperfine structure splitting of the 7² P _1/2 state of Rb⁸⁵ has been investigated with optical double resonance spectroscopy. The results are:v _F=3?F=2=52.95(6) Mc/s,A _J=1/2=17.65(2) Mc/s,g _J (7² P _1/2, Rb)=0.6668(1). From the hfs interaction constants of the 7² P multiplett a 12% core polarization contribution to the magnetic hfs of the 7² P _3/2 state can be deduced. Comparison is made between the values of 〈r ^?3〉 calculated from either the magnetic hfs or the² P fine structure separation.     

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.     

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.     

Hyperfeinstruktur des 82P3/2-Terms von Cäsium 134

The electric quadrupole interaction constantB of the 8p²P_3/2 state of Cs¹³⁴ has been determined by an optical double resonance measurement of the hyperfine structure transition v_F=11/2?F=9/2=47.84(12) Mc/s. The results are: B _8P ¹³⁴ =8.06(20) Mc/s and Q _8P ¹³⁴ =+ 0.427(8) · 10^?24cm². Comparison is made between the measurements in the 7p and 8p electronic states: Q _8P ¹³⁴ /Q _7P ¹³⁴ =0.977(20). The ratio of the corresponding Sternheimer correction factors yields the value C_7p/C_8P=0.982.     

Bestimmung des (631)K=1/2, I=1/2-Zustandes im U 239

Theγ-ray spectrometer at the DR 3-reactor at Risø was used to investigate the low energyγ-lines of U 239 which are emitted during neutron-capture in U 238. Very closely lying lines have been found between 500 and 650 keV. The big intensity of the 133 keV line and the lack of other transitions of appropriate energy and intensity point out that this line corresponds to the hinderedE 2-transition from the (631)I=1/2⁺ level to the (622)I=5/2⁺ groundstate. A suggestion was made for the decay possibility of the octupole states at 700 keV found by N.Fiebiger.     

Die Abhängigkeit der Lebensdauer des Tl 72 S 1/2-Zustandes von den Anregungsbedingungen in einem Resonanzfluoreszenzexperiment

The lifetime of the Thallium 7² S _1/2-level has been studied by measuring the phase of the modulated intensity of fluorescens light. The lifetime was found between 6.65 and 8.25 nsec depending on the exciting conditions.

     

Zerfall des zweiten 2+-Zustandes von44Ca

Solid solutions between the compounds Nb₃Al, Nb₃Ga, Nb₃Ge, Nb₃In, and Nb₃Sn have been prepared by arc melting in argon atmosphere. Transitions to superconductivity, lattice constants and values of microhardness have been measured for all samples as cast as well as annealed. In agreement withMatthias et al. the highest transition to superconductivity at 20.05 °K has been observed in the system Nb₃(Al_1?xGe_x). A relation between microhardness and transition to superconductivity also expressed byMatthias has been verified for most of the systems.     

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

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

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.     

Präzisionsmessung der Hyperfeinstruktur des 52P3/2-Terms und des 62P3/2-Terms von Rb85 und Rb87

To study the modification of the value of the nuclear quadrupole moment obtained without Sternheimer correction from measurements in states with different principal quantum numbers, the hyperfine structure splitting of the 5² P _3/2 and the 6² P _3/2 excited states of Rb I has been investigated with the optical double resonance method. The experiments, in which isotopic enriched samples of Rb⁸⁵ and Rb⁸⁷ were used, have been carried out in the 5² P _3/2 state without a static magnetic field. In the 6² P _3/2 state, a static magnetic field was applied. For the 5² P _3/2 state, the hyperfine structure constants areA(Rb⁸⁵)=25.029(16) Mc/s,B(Rb⁸⁵)=26.032(70) Mc/s,A(Rb⁸⁷)=84.852(30) Mc/s,B(Rb⁸⁷)=12.611(70) Mc/s. The corresponding constants for the 6² P _3/2 state areA(Rb⁸⁵)=8.25(10) Mc/s,B(Rb⁸⁵)=8.16(20) Mc/s,A(Rb⁸⁷)=27.96(35) Mc/s,B(Rb⁸⁷)=3.95(10) Mc/s. The values of the nuclear quadrupole moments, derived from both finestructure states, can be brought into agreement when the Sternheimer core correction is applied. The Landé factor for the 6² P _3/2 state isg _j=1.334(1).     

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.     

Messung der Hyperfeinstruktur-Aufspaltung des metastabilen3 P 2-Zustandes des Kr83 nach der Atomstrahl-Resonanzmethode

The hyperfine structure splitting of the metastable³ P ₂-state of Kr⁸³ has been measured by the atomic beam magnetic resonance method. A glow discharge served as a source of metastable atoms which were detected by surface ejection of electrons from a metal. In order to improve the signal-to-noise-ratio the magnetic C-field was modulated at a frequency of 37 cps. From the measured splittings the following hfs coupling constants were determined:

$$A(^3 P_2 ) = - (243 \cdot 970 \pm 0 \cdot 004)Mc/sec,B(^3 P_2 ) = - (452 \cdot 12 \pm 0 \cdot 08)Mc/sec.$$