Two-color three-photon excitation studies of thallium Rydberg states (original) (raw)
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The European Physical Journal D - Atomic, Molecular and Optical Physics, 1998
Results of broadening and shift measurements of Doppler-free two-photon lines for transitions from the ground state to the nPJ Rydberg states with intermediate principle quantum numbers of atomic thallium perturbed by rare gases are reported. The rates show a distinct behaviour in this range of principle quantum numbers and significant dependence on the total angular momentum of the upper nP state. The experimental results are compared with calculations using a Van der Waals potential and a superposition of polarization and Fermi potentials. Additionally, broadening and shift rates of the transition Tl 6P 3/2-9P 3/2 have been measured for quadrupolar as well as for mainly scalar excitation. The rates for both kinds of excitation coincide within the limits of error reflecting the small perturbation of the 6P 3/2 state compared to that of the upper 9P 3/2 state. PACS. 32.70.-n Intensities and shapes of atomic spectral lines-31.50.+w Excited states-34.20.-b Interatomic and intermolecular potentials and forces, potential energy surfaces for collisions
Two-step laser spectroscopy of the even-parity Rydberg levels of neutral tin
Journal of Physics B: Atomic, Molecular and Optical Physics, 1999
We report the first measurements of the even-parity J = 1 and 2 levels of neutral tin using a two-step laser excitation technique in conjunction with an atomic beam apparatus. The Rydberg series 5pnp ( 1 2 , 3 2 ) 2 (11 n 45) and 5pnp ( 1 2 , 3 2 ) 1 (12 n 18) have been observed converging to the first ionization limit. In addition, five p-levels; 5p8p ( 3 2 , 1 2 ) 1,2 , 5p8p ( 3 2 , 3 2 ) 0,1,2 and three f-levels 5p5f ( 3 2 , 5 2 ) 1,2 and 5p5f ( 3 2 , 7 2 ) 2 converging to the second ionization threshold have been identified. The perturbations among the J = 2 levels have been studied using three-channel quantum defect theory. 0953-4075/99/245669+11$30.00
Tm autoionization rydberg states in the vicinity of the third and fourth atomic ionization limit
Zeitschrift f�r Physik D: Atoms, Molecules and Clusters, 1989
The energies of about 200 autoionization Rydberg states of the thulium atom have been measured in the 57380-58960cm -1 energy region by laser multistep excitation and subsequent autoionization with an accuracy of +0.4 c m -i . More than a half of the states have been grouped in series. New spectroscopic information has been derived. Three-step two-colour effective excitation schemes have been proposed for thulium atom detection.
Systematic studies of highly excited Rydberg states in ions with two valance electrons
Journal of Physics B: Atomic, Molecular and Optical Physics, 2006
A method, based on the multiconfiguration Hartree-Fock approach, for ab initio calculations of Rydberg states has been developed. The method has been tested for a number of highly excited Rydberg states, with quantum numbers l = 4-8 and n 9, in Mg-like and Be-like ions. The results are compared with Hartree-Fock calculations to investigate the influence of correlation and, to a lesser extent, relativistic effects. The theoretical spectra for Cl VI and the lifetimes of the 2s6g-levels in O V are in excellent agreement with experimental results. More limited calculations have also been done for some Rydberg series in S V and Ar VII to illustrate the changing influence of perturbers along the isoelectronic sequence. The difficulties of using isoelectronic extrapolation/interpolation in making predictions for this kind of systems are discussed.
Multi-photon excitation spectra of the 3s n ell (ell = 0, 1, 2 and 3) Rydberg states of magnesium
Journal of Physics B: Atomic, Molecular and Optical Physics, 2007
New experimental data on the highly excited = 0, 1, 2 and 3 Rydberg states of magnesium have been acquired using two-photon and two-step laser excitation technique in conjunction with a thermionic diode ion detector. The new observations include even parity 3sns 1 S 0 (8 n 24) and 3snd 1 D 2 (7 n 62) Rydberg states approached directly from the 3s 2 1 S 0 ground state via two-photon excitation, and the odd parity 3snp 1 P 1 (20 n 61) and 3snf 1 F 3 (14 n 66) Rydberg states accessed by the two-step excitation process via 3s4s 1 S 0 and 3s3d 1 D 2 intermediate states. The Rydberg relation fit to the new data of the np 1 P 1 and nf 1 F 3 series yields the binding energies of the 3s4s 1 S 0 and 3s3d 1 D 2 levels as 18 167.702 cm −1 and 15 267.972 cm −1 , respectively. By adding the binding energies to the corresponding energies of the aforementioned levels, a precise value of the first ionization potential of magnesium is determined as 61 671.04 ± 0.04 cm −1 . Using this ionization potential value, the quantum defects for the ns 1 S 0 , np 1 P 1 , nd 1 D 2 and nf 1 F 3 Rydberg series have been determined as 1.526(2), 1.046(2), 0.602(2) and 0.049(2) cm −1 respectively.
MEASUREMENT OF STARK AMPLITUDES IN THE 62P1/2-> 72p 1/2 TRANSITION OF ATOMIC THALLIUM
1985
This thesis describes the measurement of Stark amplitude coefficients a and B for the 6 2 Pl/2 ~ 72pl/2 transition of 205 Tl in an external static electric field E. The coefficient a is determined by-+ measuring the absorption of linearly polarized 293 nm light (E 1/ E) at the F=1 ~ F'=1 resonance in a cell with known electric field and interaction length, and calibrated thallium density. Then a is determined from the ratio S2/a 2 of intensities of the F=O ~ F=1 and F=O ~ F=O resonance lines in fluorescence. The final results are a = (1.30 ± 0.06) x 10-5 ~o cm/V and S = (1.08 ± 0.05) x 10-5 ~o cm/V (where ~o = electron Bohr magneton). S is combined with a previous measurement of 1m ep/s to yield the parity non-conserving electric dipole amplitude e p. .. ' .
Measurement of Stark amplitudes in the 6SP/sub 1/2/ 7SP/sub 1/2/ transition of atomic thallium
1985
This thesis describes the measurement of Stark amplitude coefficients a and e for the 6 P, , ? •» 7 P, .-transition of Tl in an external sxatic electric field E. The coefficient a is determined by measuring the absorption of linearly polarized 293 nm light (e II E) at the F=l •> F'=l resonance in a cell with known electric field and interaction length, and calibrated thallium density. Then s is 2 2 determined from the ratio 8 la of intensities of the F=0 •> F=l and F=0->• F=0 resonance lines in fluorescence. The final results are a = (1.30 * 0.06) x 10-5 WQ cm/V and B = (1.08 ± 0.05) x 10~5 UQ cm/V (where u = electron Bohr magneton), B is combined with a previous measurement of Im £ p /B to yield the parity non-conserving electric dipole amplitude £ p .
Journal of Physics B Atomic Molecular and Optical Physics
We report new experimental data on the even parity 5p [iopmath latex="$_{1/2} n$"] 1/2n [/iopmath] p and nf [iopmath latex="$J = 1$"] J = 1 [/iopmath] , 2 Rydberg series of tin excited from the 5p6s [iopmath latex="$(3/2,1/2)_1$"] (3/2,1/2)1 [/iopmath] intermediate level using a two-step laser excitation technique in conjunction with an atomic beam apparatus. The Rydberg series 5pnf [iopmath latex="$(1/2,5/2)_2$"] (1/2,5/2)2 [/iopmath] [iopmath latex="$(12\le n \le 46)$"] (12n46) [/iopmath] and 5pnp [iopmath latex="$(1/2,1/2)_1$"] (1/2,1/2)1 [/iopmath] [iopmath latex="$(20\le n \le 31)$"] (20n31) [/iopmath] are reported for the first time, whereas the 5pnp [iopmath latex="$(1/2,3/2)_2$"] (1/2,3/2)2 [/iopmath] [iopmath latex="$(16\le n \le 56)$"] (16n56) [/iopmath] series have been extended to higher principal quantum number. The previously reported three p levels, 5p8p [iopmath latex="$(3/...
Lifetimes along perturbed Rydberg series in neutral thallium
Journal of Physics B: Atomic, Molecular and Optical Physics, 2005
Radiative lifetimes of 15 Tl I levels belonging to the 6s 2 ns 2 S 1/2 (n = 7-14) and 6s 2 nd 2 D 3/2 Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence technique. All the measured levels have been excited from the ground state 6s 2 6p 2 P 0 1/2 (odd parity) with a single-step excitation process. The general perturbation of the ns series by the 6s6p 2 configuration and the corresponding modification of the lifetimes are adequately reproduced by a theoretical model including core-polarization effects and combined with a least-squares fit to the observed energy levels. The general behaviour of the lifetime values for the 6s 2 np odd levels along the Rydberg series is also well reproduced. The use of the multiconfiguration quantum defect theory has allowed us to obtain lifetime values along the 6s 2 ns 2 S 1/2 series up to levels with n = 31.