Magneto-optical trapping of bosonic and fermionic neon isotopes and their mixtures: isotope shift of the 3P2 ↔ 3D3 transition and hyperfine constants of the 3D3 state of 21Ne

We have magneto-optically trapped all three stable neon isotopes, including the rare ²¹Ne, and all two-isotope combinations. The atoms are prepared in the metastable ³P₂ state and manipulated via laser interaction on the ³P₂ ? ³D₃ transition at 640.2?nm. These cold (T ≈ 1?mK) and environmentally decoupled atom samples present ideal objects for precision measurements and the investigation of interactions between cold and ultracold metastable atoms. In this work, we present accurate measurements of the isotope shift of the ³P₂ ? ³D₃ transition and the hyperfine interaction constants of the ³D₃ state of ²¹Ne. The determined isotope shifts are (1625.9 ± 0.15)?MHz for ²⁰Ne ? ²²Ne, (855.7 ± 1.0)?MHz for ²⁰Ne ? ²¹Ne, and (770.3 ± 1.0)?MHz for ²¹Ne ? ²²Ne. The obtained magnetic dipole and electric quadrupole hyperfine interaction constants are A(³D₃) = (?142.4 ± 0.2)?MHz and B(³D₃) = (?107.7 ± 1.1)?MHz, respectively. All measurements give a reduction of uncertainty by about one order of magnitude over previous measurements.     

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.     

Investigation of hyperfine structure and isotope shift of the 605.5 nm-line of Lu176 by laser spectroscopy

Using a tunable single mode dye laser the hyperfine structure of the transition 5d6s ^{2 2} D _5/2 — 5d6s6p ⁴ F _5/2 has been investigated for the Lu-isotopes Lu¹⁷⁵ and Lu¹⁷⁶. From our measurements the following values for the hyperfine constantsA andB could be deduced Lu¹⁷⁶ 5d6s6p ⁴ F _5/2:A=698.4 (0.4) MHz,B=1,564 (10) MHz 5d6s ^{2 2} D _5/2:A=104.1 (0.3) MHz.B=2,631 (6) MHz Lu¹⁷⁵ 5d6s6p ⁴ F ^5/2:A=987.2(0.4) MHz,B=1,117(6) MHz. The isotope shift between the line centers has been determined to be IS(176-175, 605.5 nm)=?420(10) MHz.     

Isotope shift and HFS ofD 1 lines in Na-22 and 23 measured by saturation spectroscopy

High resolution saturation spectroscopy was applied to measure the relative isotope shift of theD ₁ lines in radioactive²²Na against²³Na in vapour cells. The result,δν=758.5(7) MHz, combined with other known values, indicates that the field shift is negligible in sodium isotopes. The hyperfine coupling constant of the² P _1/2 level in²²Na was found to be 37.0(1) MHz. A frequency offset locking technique is described which renders an accurate frequency calibration and achieves a long-term frequency stabilization.     

Hyperfine splitting and isotope shift in the atomic D2 line of 22,23Na and the quadrupole moment of 22Na

The hyperfine structure of the D₂ optical line in ²²Na and ²³Na has been investigated using high resolution laser spectroscopy of a well-collimated atomic beam. The hyperfine splitting constants A and B for the excited 3p ²P_3/2 level for both investigated sodium isotopes have been obtained. They are as follows: A(22) = 7.31(4) MHz, B(22) = 4.71(28) MHz, A(23) = 18.572(24) MHz, B(23) = 2.723(55) MHz. With this data, using the high precision MCHF calculations for the electric field gradient at the nucleus, the electric quadrupole moment of ²²Na has been deduced: Q_s(22) =+0.185(11) b. The sign of Q_s(22), determined for the first time, indicates a prolate nuclear deformation. A precise value of the isotope shift ^22,23Na in the D₂ line has also been obtained. Received: 26 February 1998 / Revised version: 25 June 1998     

Measurement of the fine structure separation in the 42 D term of lithium by the method of electric field induced level anti-crossing

An electric field is employed to convert lithium 4² D Zeeman level crossings into anti-crossings. The lithium atoms are excited by electron impact. The anti-crossings are detected by the change in polarization of the light emitted in the 4² D-2² P transition. From the corresponding values of the magnetic field, we obtain 400 (10) MHz for the zero field fine structure energy separationE(4² D _5/2)-E(4² D _3/2).     

Investigation of the ν5 band of methylacetylene by infrared laser Stark and microwave spectroscopy

Microwave spectra have been studied in the ground and v₅ = 1 (CC stretching mode) states of methylacetylene. From these data, dipole moments and rotational and centrifugal distortion constants have been determined, as follows: μ_D⁽⁰⁾ = 0.7839 ± 0.0010 D, μ_D⁽⁵⁾ = 0.7954 ± 0.0010 D, B₅ = 8508.119 ± 0.003 MHz, D_J⁽⁵⁾ = 1.8 ± 0.2 kHz, and D_JK⁽⁵⁾ = 169 ± 1 kHz. Laser Stark spectra have been obtained for the ν₅ band of this molecule and from these spectra the following vibration-rotation parameters have been determined: ν₅⁰ = 93.27540 ± 0.00007 cm^?1, A₅ - A₀ = ?227.0 ± 2.3 MHz and D_K⁽⁵⁾ - D_K⁽⁰⁾ = ?0.05 ± 0.50 MHz. The higher-J and -K states of the v₅ = 1 state appear to be purturbed.     

Excited states in124Xe

The isomer shift in the optical transition Eu II 4f⁷(⁸S ₇ ^2/o )⁶p_3/2 ^(7/2,3/2)4?4f⁷ (⁸S ₇ ^2/o )5d⁹D ₄ ^o , λ=6O4.95 nm, has been measured between the isotope^152gEu(3^?) and its isomer^152mEu(0^?). From the valuev(^152gEu)–v(^152mEu)=736(10) MHz the deformation parameter of^152mEu has been estimated to be^152mβ?+0.25. This value is smaller than^152gβ as obtained from isotope shift measurements and the spectroscopic quadrupole moment. The influence of the shape difference on the decay of^152mEu is discussed.     

The high resolution rotational spectrum of 2-cyanoaziridine

The microwave spectrum of 2-cyanoaziridine has been measured and assigned. Only the spectrum of the cis isomer has been detected although extensive searches for transitions from the trans isomer have been made, suggesting that it is at least 11 kJ mol^?1 less stable. The following nuclear quadrupole coupling constants were obtained: χ_aa(1) = ?1.249(14), χ_bb(1) = 1.407(12), χ_aa(2) = ?3.547(6), χ_bb(2) = 1.865(8) MHz, the former pair probably referring to the amino nitrogen and the latter pair to the nitrile nitrogen. The rotational constants derived from the analysis are: A = 16877.718(32), B = 3528.931(4), C = 3373.065(4) MHz, D_N = 1.10(4) kHz.     

Laser-rf double-resonance hyperfine structure measurements of the metastable 3d 4s 1 D 2 state of43Ca

The hyperfine structure of the (3(d 4s)¹ D ₂metastable state of⁴³Ca has been measured using theABMR-LIRF method (atomic beam magnetic resonance, detected by laser induced resonance fluorescence). The measurements yielded for the magnetic dipole and electric quadrupole constantsA=?17.650(2) MHz andB=?4.642(12) MHz, respectively. From the measuredB factor the spectroscopic electric quadrupole moment (uncorrected for shielding effects) has been calculated to beQ(⁴³Ca)=?0.062(12) barn. In addition, isotope shifts in the lines (3d 4s)¹ D ₂(3d 4p)¹ F ₃ ⁰ and (3d 4s)¹ D ₂(4s 5p)¹ p ₁ ⁰ for the stable calcium isotopes have been obtained by high resolution laser spectroscopy.     

Hyperfine-structure investigation in the 6s5d configuration of135Ba and137Ba

The hyperfine structure of the metastable states of the 6s5d configuration of¹³⁵Ba and¹³⁷Ba has been studied by the atomic-beam magnetic resonance (ABMR) method. The metastable barium states were populated in a plasma-discharge inside the atomic-beam oven. The atoms emerging from the ABMR-apparatus were detected by the use of a dyelaser. Compared to conventional methods this technique has the advantage of being state selective. The following magnetic dipole and electric quadrupole interaction constantsa andb have been obtained:¹³⁷Ba:a(³ D ₁)=?520.536 (3) MHzb(³ D ₁)=17.890 (3) MHza(³D₂=415.928 (3) MHzb(³D₂)=25.899 (13) MHza(³D₃)=456.559 (4) MHzb ³D₃=47.390 (16) MHz¹³⁵Ba:a ³ D ₁=?465.166 (4) MHzb(³D₁)=11.642 (4) MHza(³D₂)=371.736(4) MHzb ³ D ₂=16.745 (14) MHza(³D₃)=408.038 (6) MHzb(³D₃)=30.801 (24) MHz Using these constants and the earlier known ones for the¹ D ₂ state the hyperfine structure for the 6s5d configuration has been analyzed with an effective hyperfine hamiltonian. Hyperfine parameters obtained from the analysis have been compared with theoretical values calculated with relativistic self-consistent-field (SCF) wavefunctions. The quadrupole moments have been evaluated with the following result Q(¹³⁵Ba) =0.20(3)b and Q(¹³⁷Ba) = 0.34(4)b uncorrected for the quadrupole shielding.     

The Zeeman spectrum of the NO molecule

The Zeeman spectrum of the NO molecule in the $\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{J =}\text{1}\text{2}$ and $\text{J =}\text{3}\text{2}$ rotational states has been studied using a molecular beam electric resonance spectrometer. High-resolution data were obtained in magnetic fields ranging from 0.1 to 0.8 T. The present measurements are combined with relevant data from the literature in a least-squares fit to determine basic molecular g factors. Seven molecular g factors and the anisotropy in the magnetic susceptibility could be determined, and a value of the electronic quadrupole moment Q_|^e was derived. The most prominent results are g_s = 2.002095(40) and Q_|^e = ?1.201(11) × 10^?38 C m², to be compared with the respective ab initio values which are 2.002087 and ?0.826 × 10^?38 C m². Furthermore, separate contributions from ²Σ⁺, ²Σ^?, and Δ² states to the electronic part of the rotational g factor were obtained, showing that the unique perturber approximation is invalid for the present example. Finally, the combination of Zeeman- and zero-field data enabled a separate determination of the spin-rotation constant and the centrifugal distortion in the spin-orbit coupling (A_D). The value of A_D derived from experiment is ?1.43(20) MHz, in good agreement with the theoretical prediction of ?1.92(8) MHz.     

Hyperfine structures and isotope shifts of the 5d 4 D 7/2→6p 4 P 5/2 0 transition in Xenon ions

Collinear fast beam-laser spectroscopy has been performed on metastable 5d ⁴ D _7/2 Xenon ions. Hyperfine structure constants for the 6p ⁴ P _5/2 ⁰ level have been derived for¹²⁹Xe:A=?1,634.9±0.9 MHz and¹³¹Xe:A=485.3±0.3 MHz andB=?116.5±2.0MHz. Changes in mean squared nuclear charge radii are derived from the measured isotope shifts.     

Subject index for volume 107

The far-infrared laser magnetic resonance spectrum of AsH in the ground X³Σ^? state has been observed using five optically pumped laser lines as sources. The AsH radical was produced by the reaction of metallic arsenic with microwave discharge products of a H₂ and O₂ mixture. From an analysis of the observed spectrum, the following rotational and fine structure constants were obtained: B₀ = 215 877.54 (23), D₀ = 9.834 (11), λ = 1 763 488 (56), and γ = ?8 114.5 (60), all in MHz with 3σ in parentheses. The hyperfine coupling constants were also determined for the two nuclei as follows: α_As = ?11.5 (14), β_As = ?159.4 (13), eQq_As = ?97.6 (72), α_H=?49.80 (66), and β_H=4.15 (60), again in MHz with 3σ in parentheses.     

Measurement of the fine-structure splitting of the 42 D state of lithium using level-crossing spectroscopy

The fine-structure splitting of the 4² D state in lithium was measured using stepwise laser excitation combined with level-crossing spectroscopy. The splitting was determined to be 456.2(0.8) MHz, a considerably higher value than the one obtained in a recent level-anticrossing measurement. The new value is in good agreement with the result of a Hartree-Fock calculation, 460.2 MHz.     

The ground state of molecular hydrogen

The v = 0?0 quadrupole spectrum of H₂ has been recorded using a 0.005-cm^?1 resolution Fourier transform spectrometer. The rotational lines S(1) through S(5) are observable in the spectra, in the region 587 to 1447 cm^?1. The spectral position for S(0) was also obtained from its v = 1-0 ground-state combination difference. The high accuracy of the H₂ measurements has permitted a determination of four rotational constants. These are (in cm^?1) B₀ = 59.33455(6); D₀ = 0.045682(4); H₀ = 4.854(12) × 10^?5; L₀ = ?5.41(12) × 10^?8. The hydrogen line positions will facilitate studies of structure and dynamics in astrophysical objects exhibiting infrared H₂ spectra. The absolute accuracy of frequency calibration over wide spectral ranges was verified using 10-μm CO₂ and 3.39-μm CH₄ laser frequencies. Standard frequencies for 5-μm CO were found to be high by 12 MHz (3.9 × 10^?4 cm^?1).     

PRECISE MEASUREMENT OF DENSITY-DEPENDENT SHIFT BY WAVELENGTH MODULATION REFLECTION SPECTROSCOPY

The density dependence of the line shift of the cesium D₂ line is studied with sub-Doppler selective reflection spectroscopy. By use of wavelength modulation and sixth-harmonics detection we observed the coefficient of the pressure-induced shift of the 6S_1/2(F=4)→6P_3/2(F'=3) hyperfine transition of the cesium D₂ line Δδ/ρ=-0.9(5)×10^-8cm³. In the limit ρ=0 a frequency shift about -3MHz remains, which may be attributed to long-range atom－surface interactions. The experimental results can be used in measurements of the local field-induced frequency shift at high atomic densities with sufficient accuracy.     

Calculation of the hyperfine structure of the 42 S 1/2, 42 P 1/2, 42 P 3/2 states in the 3d 10 nl configuration of Cu

The hyperfine structure of the 4² S _1/2, 4² P _1/2, 4² P _3/2 states in the 3d ¹⁰ nl configuration of Cu has been evaluated using many-body perturbation theory. Polarisation effects were included in all orders and correlation to third-order. By the use of iteration methods, a large number of higher order diagrams were also included. The correlation effects between the valence electron and the 3d shell were found to be very important. The results forA(² S _1/2) andA(² P _1/2) 5827MHz and 440 MHz, respectively, are in good agreement with the experimental results, whereas the result forA(² P _3/2)=83 MHz is far from the experimental value. No explanation was found for the discrepancy. The quadrupole values were found to be ?206 mb for⁶³Cu and ?185 mb for⁶⁵Cu.     

Isotope shifts of the ground state of neon: Refining the measurement results

Abstract—It has been revealed that the published results of measurements of the isotope shift of the ground state of even neon isotopes contain systematic errors. The errors are caused by the use of erroneous data regarding the absolute values of specific mass shifts of excited states and by the measurement errors of the isotope shifts themselves for transitions to the ground state. The isotope shift of the 2p⁵4s[3/2]₁ → 2p⁶(¹S₀) transition has been measured to be 2305 ± 20 MHz, the absolute specific mass shift of the 3p[3/2]₂: (2_р9) level has been determined to be 647 ± 10 MHz, and the isotope shift of the ground state has been found to be–3156 ± 30 MHz.