Magnetic Dipole Constants Research Articles

Hyperfine structure of laser-cooling transitions in fermionic erbium-167

We have measured and analyzed the hyperfine structure of two lines, one at 583nm and one at 401nm, of the only stable fermionic isotope of atomic erbium as well as determined its isotope shift relative to the four most-abundant bosonic isotopes. Our work focuses on the J->J+1 laser cooling transitions from the [Xe] 4f12 6s2 (3H6) ground state to two levels of the excited [Xe] 4f12 6s6p configuration, which are of major interest for experiments on quantum degenerate dipolar Fermi gases. From a fit to the observed spectra of the strong optical transition at 401nm we find that the magnetic dipole and electric quadrupole hyperfine constants for the excited state are Ae/h=-100.1(3)MHz and Be/h=-3079(30)MHz, respectively. The hyperfine spectrum of the narrow transition at 583nm, was previously observed and accurate Ae and Be coefficients are available. A simulated spectrum based on these coefficients agrees well with our measurements. We have also determined the hyperfine constants using relativistic configuration-interaction ab initio calculations. The agreement between the ab initio and fitted data for the ground state is better than 0.1%, while for the two excited states the agreement is 1% and 11% for the Ae and Be constants, respectively.

Hyperfine structure and isotope shift measurements of the [formula omitted]–[formula omitted] 601.8154 nm transition in Eu I by laser induced atomic beam fluorescence spectroscopy

The hyperfine structure of the ground state 4f76s2(S7/2o8) and the excited 4f76s6p(P9/28) state for both the isotopes 151Eu and 153Eu has been measured using the laser induced fluorescence spectroscopy from an effusive atomic beam. The isotope shift for the 4f76s2(S7/2o8)→601.8154nm4f76s6p(P9/28) transition of Eu I has also been measured. The precision in the measurement of the isotope shift of this transition and the hyperfine structure constants for both the isotopes of Eu has been improved using a radio-frequency modulation technique based on EOM side band generation as well as by frequency locking technique. The experimentally determined isotope shift between the 151Eu and the 153Eu isotopes for the 4f76s2(S7/2o8)→601.8154nm4f76s6p(P9/28) transition is 3549.3 (5) MHz. The values of the magnetic dipole constant (A) and the electric quadrupole coupling constant (B) for the 151Eu and 153Eu isotopes for the 4f76s2(S7/208) ground state have been found to be consistent with the values reported by the atomic beam magnetic resonance (ABMR) technique. The hyperfine coupling constants for both the isotopes of Eu for the excited 4f76s6p(P9/28) state are measured to be A(151Eu)=664.73 (9) MHz and B (151Eu)=290 (3) MHz; A(153Eu)=295.15 (7) MHz and B (153Eu)=727 (2)MHz.

Spectroscopy on a single trapped ^137Ba^+ ion for nuclear magnetic octupole moment determination

We present precision measurements of the hyperfine intervals in the 5D3/2 manifold of a single trapped Barium ion, 137 Ba+ . Measurements of the hyperfine intervals are made between mF = 0 sublevels over a range of magnetic fields allowing us to interpolate to the zero field values with an accuracy below a few Hz, an improvement on previous measurements by three orders of magnitude. Our results, in conjunction with theoretical calculations, provide a 30-fold reduction in the uncertainty of the magnetic dipole (A) and electric quadrupole (B) hyperfine constants. In addition, we obtain the magnetic octupole constant (C) with an accuracy below 0.1 Hz. This gives a subsequent determination of the nuclear magnetic octupole moment, {\Omega}, with an uncertainty of 1% limited almost completely by the accuracy of theoretical calculations. This constitutes the first observation of the octupole moment in 137 Ba+ and the most accurately determined octupole moment to date.

Wigner Crystals ofTh229for Optical Excitation of the Nuclear Isomer

We have produced laser-cooled Wigner crystals of 229Th3+ in a linear Paul trap. The magnetic dipole (A) and electric quadrupole (B) hyperfine constants for four low-lying electronic levels and the relative isotope shifts with respect to 232Th3+ for three low-lying optical transitions are measured. Using the hyperfine B constants in conjunction with prior atomic structure calculations, a new value of the spectroscopic nuclear electric quadrupole moment Q=3.11(16) eb is deduced. These results are a step towards optical excitation of the low-lying isomer level in the 229Th nucleus.

Hyperfine coupling constants of cesium 7D states using two-photon spectroscopy

Doppler-free two-photon transitions of cesium 6S1/2→7D3/2, 5/2 were observed in a thermal stabilized cell. A repeated spectrum of 75 MHz introduced from the side band of an electro-optical modulator served as a frequency marker to improve the accuracy of frequency measurement. The hyperfine magnetic dipole constant A and electrical quadrupole constant B of Cs 7D3/2, 5/2 can be derived from the splitting intervals of the observed spectra. The results are: A=7.36(07) MHz, B=−0.88(87) MHz for the 7D3/2 state, and A=−1.81(05) MHz, B=1.01(1.06) MHz for the 7D5/2 state. These coefficients are improvements for testing high-precision measurements and determining fundamental physical constants.

Isotope shift and hyperfine structure measurements of 4s 2S1/2 → 6s 2S1/2 two-photon transition of potassium isotopes

Hyperfine splittings for the 39K and 41K isotopes and the isotope shift for the 4s 2S1/2 → 6s 2S1/2 two-photon transition have been measured using sub-Doppler fluorescence spectroscopy. We have accurately measured the transition isotope shift, and a discrepancy has been found in the earlier reported transition isotope shift value, which has been corrected. The resulting hyperfine splitting values of 418.2 (5) and 230.4 (1.3) MHz for the 39K and 41K isotopes respectively are in agreement with previous measurements. The precision of the absolute frequency values for the two-photon transition has been improved by about two orders. Our measured magnetic dipole constants for the upper 6 2S1/2 state for the 39K and the 41K isotopes are consistent with the earlier measured values.

Precise measurement of hyperfine structure in the2P1/2state ofLi7using saturated-absorption spectroscopy

We report a precise measurement of the hyperfine interval in the $2{P}_{1/2}$ state of $^{7}\mathrm{Li}$. The transition from the ground state (${D}_{1}$ line) is accessed using a diode laser and the technique of saturated-absorption spectroscopy in hot Li vapor. The interval is measured by locking an acousto-optic modulator to the frequency difference between the two hyperfine peaks. The measured interval of 92.040(6) MHz is consistent with an earlier measurement reported by us using an atomic-beam spectrometer [Das and Natarajan, J. Phys. B 41, 035001 (2008)]. The interval yields the magnetic dipole constant in the ${P}_{1/2}$ state as $A=46.047(3)$, which is discrepant from theoretical calculations by $>80$ kHz.

Hyperfine splitting constants in the optical transition $\boldsymbol{{4{f}^{7}} {6{s}^{2}} \;{^{8}{\rm S}_{7/2}} \to {4{f}^{7}} {6{s}6{p}}\; {^{6}{\rm P}_{5/2}} \ {\rm of} \ {^{151-155}{\rm Eu}}}$ isotopes and hyperfine anomaly

Using the method of laser-induced fluorescence in an atomic beam we have measured the hyperfine splitting constants, A and B, of the ground and excited states of the optical transition 4f76s28S\(_{1/2}\to 4f^{7}\)6s6p6P5/2 (564.58 nm) for 151 − 155Eu isotopes. For all isotopes, the magnetic dipole constants of the 6P5/2 atomic level are determined to a precision better than 0.04%. The A and B constants for the ground state 8S7/2 of the radioactive 152,154,155Eu were obtained for the first time with a precision better than 0.5%. Our data along with previous ground state hyperfine structure measurements for the stable europium isotopes allow us to determine the hyperfine anomaly for mentioned Eu isotopes.

Hyperfine-structure-constant determination and absolute-frequency measurement of the Rb4D3/2state

The frequency of a laser diode is stabilized onto the line centers of double-resonance optical pumping spectra, and the absolute frequencies of the hyperfine-structure components of the $5{P}_{3/2}\text{\ensuremath{-}}4{D}_{3/2}$ excited-state transition for two isotopes of $^{87}\text{R}\text{b}$ and $^{85}\text{R}\text{b}$ atoms are measured using a fiber femtosecond frequency comb system. The $4{D}_{3/2}$ state hyperfine-structure constants of the two Rb isotopes are determined by utilizing the measured absolute optical frequency and the ratio of the hyperfine-structure constants for the two Rb isotopes from the accurately determined values of other states of rubidium. The magnetic-dipole constants $A$ are determined to be 24.75(12) MHz for $^{87}\text{R}\text{b}$ and 7.329(35) MHz for $^{85}\text{R}\text{b}$. The uncertainties of both results are reduced by one order compared to previous results. The electric-quadrupole constants $B$ are determined to be 2.19(11) and 4.52(23) MHz for $^{87}\text{R}\text{b}$ and $^{85}\text{R}\text{b}$, respectively

Measurement of the hyperfine splitting of the6S1/2level in rubidium

We present a measurement of the hyperfine splitting of the 6S$_{1/2}$ excited level of rubidium using two photon absorption spectroscopy in a glass cell. The values we obtain for the magnetic dipole constant A are 239.18(03) MHz and 807.66(08) MHz for $^{85}$Rb and $^{87}$Rb, respectively. The combination of the magnetic moments of the two isotopes and our measurements show a hyperfine anomaly in this atomic excited state. The observed hyperfine anomaly difference has a value of $_{87}\delta_{85}=-0.0036(2)$ due to the finite distribution of nuclear magnetization, the Bohr-Weisskopf effect.

Comparison of hyperfine anomalies in the [formula omitted] and [formula omitted] levels of 85Rb and 87Rb

We observe a hyperfine anomaly in the measurement of the hyperfine splitting of the 6S1/2 excited level in rubidium. We perform two step spectroscopy using the 5S1/2→5P1/2→6S1/2 excitation sequence. We measure the splitting of the 6S1/2 level and obtain for the magnetic dipole constants of 85Rb and 87Rb A=239.18(4)MHz and A=807.66(8)MHz, respectively. The hyperfine anomaly difference of δ8587=−0.0036(2) comes from the Bohr Weisskopf effect: a correction to the point interaction between the finite nuclear magnetization and the electrons, and agrees with that obtained in the 5S1/2 ground state.

Measurement of the absolute energy level and hyperfine structure of the ^87Rb 4D_5/2 state

We have measured the absolute frequency of the excited state transition 5P(3/2)-4D(5/2) in a (87)Rb atom with a femtosecond frequency comb, utilizing the recently developed spectroscopic technique of the double resonance optical pumping method. The absolute energy level of the 4D(5/2) state is determined by measuring the absolute frequency of the 5S(1/2)-5P(3/2) transition simultaneously. The hyperfine structure constants of the 4D(5/2) state are obtained by using the measured frequency. The magnetic dipole constant, A, is determined to be (-16.747+/-0.010) MHz with an uncertainty reduced 60-fold compared with a previous result. The electric quadrupole constant, B, is determined, for what is to our knowledge the first time, to be (4.149+/-0.059) MHz.

Precise hyperfine structure measurements of La II utilizing the laser and rf double resonance technique

The hyperfine structure of the 5d 6s b1D2 level in La II has been measured utilizing the laser and radio-frequency double resonance (LRDR) technique in a collinear geometry. Magnetic dipole and electric quadrupole hyperfine constants have been extracted and the results have been compared with previous measurements. With the present technique drastically improved accuracy has been obtained.

Hyperfine structure of the ground state in singly ionized manganese

We report the first experimental measurements and theoretical calculations for the hyperfine splitting of the 3d5 4s ground state of Mn ii. The hyperfine structure constants were determined using Fourier transform spectroscopy with a hollow cathode discharge lamp. The uncertainties in the magnetic dipole constants, A, are between 3 × 10−4 and 5 × 10−4 cm−1. Extensive configuration interaction calculations of the hyperfine splitting of the a7S3 ground state have been carried out to compare with the experimental measurements. In addition, we give wavelengths for three resonant transitions to the ground state of Mn ii, accurate to a few parts in 108. These wavelengths are of interest in astrophysical applications such as studies of the time variation of the fine structure constant.

Comparative studies using coupled-cluster and unitary coupled-cluster methods: nuclear quadrupole moment, hyperfine constants and transition properties of 27Al

The magnetic dipole and electric quadrupole hyperfine constants of Aluminium (27Al) atom are computed using the relativistic coupled cluster (CC) and unitary coupled cluster (UCC) methods. Effects of electron correlations are investigated using different levels of CC approximations and truncation schemes. The ionization potentials, excitation energies, transition probabilities, oscillator strengths and nuclear quadrupole moment are computed to assess the accuracy of these schemes. The nuclear quadrupole moment obtained from the present CC and UCC calculations in the singles and doubles approximations are 142.5 mbarn and 141.5 mbarn, respectively. The discrepancies between our calculated IPs and EEs and their measured values are better than 0.3%. The other one-electron properties reported here are also in excellent agreement with the measurements.

Doppler-Free Two-Photon Spectroscopy of 6S1/2–6D3/2,5/2Transition in Cesium

The Doppler-free two-photon spectra of the 6 S 1/2 ( F = 3)–6 D 3/2 ( F = 2 to 5), 6 S 1/2 ( F = 4)–6 D 3/2 ( F = 2 to 5), 6 S 1/2 ( F = 3)–6 D 5/2 ( F = 5 to 1) and 6 S 1/2 ( F = 4)–6 D 5/2 ( F = 6 to 2) transitions in cesium are observed using a titanium-sapphire laser. These spectra can be used as an optical frequency standard. The hyperfine coupling constants A (magnetic dipole constant) and B (electric quadrupole constant) are determined using spectral line splittings, giving A = 16.17(17) MHz and B = 0.11(127) MHz for the 6 D 3/2 state, and A =-4.56(9) MHz and B = -0.35(183) MHz for the 6 D 5/2 state.

Multiconfiguration Dirac–Hartree–Fock calculations of the hyperfine structures of radium

The multiconfiguration Dirac–Hartree–Fock model has been employed to calculate the magnetic dipole and electric quadrupole hyperfine constants of the 7s6d 3D1, 7s6d 3D2, 7s6d 3D3 and 7s6d 1D2 states of 22388Ra. This paper complements the previously published hyperfine constants for the 7s7p 1P1 and 7s7p 3P1,2 states, yielding the hyperfine structure data for all levels belonging to the two lowest excited-state configurations, 7s7p and 7s6d, of neutral radium.

Hyperfine Structure Measurements of Neutral Manganese with Fourier Transform Spectroscopy

We report experimental hyperfine structure constants of levels in the neutral manganese atom, measured using Fourier transform spectroscopy of hollow cathode discharges. In total, 208 spectral lines of astrophysical interest have been analyzed to obtain hyperfine structure constants for 106 levels in Mn i, of which 67 have no previous hyperfine structure measurements. The uncertainties in the magnetic dipole constants, A ,a re between 1; 10 � 4 and 5 ;10 � 4 cm � 1 . Hyperfine structure constants for an additional 18 levels compiled from the literature are also given. Subject headingg atomic data — line: profiles — methods: laboratory

Comparative studies of the magnetic dipole and electric quadrupole hyperfine constants for the ground and low lying excited states of 25Mg+

We have employed the relativistic coupled cluster theory to calculate the magnetic dipole and electric quadrupole hyperfine constants for the ground and low lying excited states of singly ionized magnesium. Comparison with experimental and the other theoretical results are done and predictions are also made for a few low lying excited states which could be of interest. We have made comparative studies of the important many body effects contributing to the hyperfine constants for the different states of the ion.

Calculation of the magnetic dipole constant of the hyperfine structure of the 6 S 5/2(3d 54s 2) term in the atomic spectrum of manganese

The contributions of spin polarization, valence correlations, and relativistic effects to the magnetic dipole constant of the hyperfine structure of the 6S5/2 (3d54s2) term in the atomic spectrum of manganese are calculated and analyzed by the configuration interaction method and in the framework of the perturbation theory.