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1.
H.-L. Xu Z.-K. Jiang S. Svanberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):323-326
Natural radiative lifetimes of eight levels in Tm I ( 4f
135d6p and 4f
125d6s
2 configurations), two levels in Tm II ( 4f
125d6s configuration) and three levels in Tm III (4f
125d configuration) have been measured by using time-resolved laser spectroscopy. Free thulium atoms, as well as singly and doubly
ionized ions, were obtained in a laser-induced thulium plasma and the investigated states were selectively populated by a
single-step excitation process with a tunable narrow-band laser pulse.
Received 20 August 2002 / Received in final form 7 January 2003 Published online 4 March 2003
RID="a"
ID="a"e-mail: huailiang.xu@fysik.lth.se 相似文献
2.
Z.G. Zhang Z.S. Li S. Svanberg P. Palmeri P. Quinet E. Biémont 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(3):301-305
Lifetimes of three levels belonging to the configuration 4f
135d with J = 1 in Yb III have been measured for the first time using the time-resolved laser-induced fluorescence method. Experimental
transition probabilities have been deduced for the transitions between the levels studied and the ground state. The comparison
of the experimental lifetimes with theoretical data, deduced within the relativistic Hartree-Fock (HFR) approach, underlines
the dramatic importance of an adequate consideration of core-polarization effects in the theoretical model and the sensitivity
of one of the lifetime values to small correlation effects.
Received 2 April 2001 相似文献
3.
H.L. Xu A. Persson S. Svanberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):233-236
New radiative lifetime measurements based on time-resolved laser-induced fluorescence techniques are reported for 18 even-parity
levels belonging to the 4f5d26p and 4f
25d
2 configurations of Ce I and 6 even-parity levels belonging to the 5d26s, 4f5d6p, and 4f6s6p configurations of Ce II. Free neutral and singly ionized cerium atoms were produced by laser ablation. The Ce I and Ce II
levels range in energy from 26 545 to 29 102 cm-1, and 42 573 to 48 152 cm-1, respectively.
Received 25 September 2002 Published online 4 March 2003 相似文献
4.
Z.S. Li A. Persson S. Svanberg H.P. Garnir E. Biémont 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(1):11-14
Radiative lifetimes of the highly exited states s and d of neutral sulphur have been measured using time-resolved laser-induced fluorescence. The sulphur atoms were generated in
a laser-produced plasma. The investigated states were populated through a two-step process involving a two-photon excitation
to the lowest excited triplet state of even parity
, followed by a one-photon excitation to the investigated state. We obtained ns and ns. These values are much longer than theoretically predicted ones and much shorter than those indirectely inferred from
astronomical data.
Received: 9 February 1998 / Accepted: 24 February 1998 相似文献
5.
N. Bhattacharya B. Bapat S.A. Rangwala S.V.K. Kumar E. Krishnakumar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(2):125-129
Lifetime measurements have been carried out for some low lying (n
= 2) levels in the four-electron ions Cl XIV and S XIII using the beam-foil technique. Accurate oscillator strengths for the
2
s2
1
S
- 2
s
2
p
1
P
o transition have been determined by the inclusion of prominent cascades in the analysis. Lifetimes of the levels of the 2
p2
3
P
j multiplet have also been measured for both ions. The results are compared with theoretical predictions and earlier measurements.
Received: 29 October 1997 / Revised: 10 February 1998 / Accepted: 5 March 1998 相似文献
6.
N. Beverini E. Maccioni F. Sorrentino V. Baraulia M. Coca 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):223-228
We have measured the ratio between the transition probabilities of two forbidden lines in Ca: the intercombination line at
657.3 nm and the E
2 line at 457.5 nm. The value we obtained for this ratio is (54.1±2.4). Combined with the most accurate value available in literature for the lifetime of the
3
P
1
level, our measurement gives a value of (54.4±4.0) s-1 for the
1
S
0
↦
1
D
2
transition probability, significantly more accurate than the previous determinations.
Received 17 June 2002 / Received in final form 9 December 2002 Published online 4 March 2003 相似文献
7.
M.B. Das S. Karmakar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):229-231
Lifetimes of some 3p5nd (n
= 4, 5, 6, 7) levels of neutral argon have been measured by high frequency deflection technique with a delayed coincidence single
photon counting arrangement. The measurements have been performed under conditions where pressure dependent effects are negligible.
Lifetimes of some of the levels have been measured for the first time. The results have been compared with other experimental
and theoretical values.
Received 7 August 2002 / Received in final form 20 December 2002 Published online 24 April 2003 相似文献
8.
B. Saha A.K. Das P.K. Mukherjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):33-37
Transition energies, oscillator strengths and transition probability values for radiative transitions have been calculated
for the highly ionised atoms of Si isoelectronic sequence from Mn11+ to Kr22+ for the singly excited states up to principal quantum number n = 7. Time-dependent coupled Hartree-Fock (TDCHF) theory has been used to estimate such transition properties. Most of the
results for the oscillator strengths and transition probabilities are new. Transition energies agree reasonably well with
available spectroscopic values.
Received 25 January 2000 and Received in final form 24 October 2000 相似文献
9.
K. Blagoev R. Roussev A. Morozov K. Iskra L. Windholz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(2):159-163
Radiative lifetimes of 7d, 8d 1
D
2 excited states of Hg I are measured using pulsed two-photon excitation from the ground [Xe]5d
106s
2
1
S
0 mercury state, detecting the decay of the laser-induced fluorescence. The results are compared with theoretical values, obtained
by means of a Hartree-Fock single configuration method, taking into account electron configuration interaction. The radiative
lifetime value dependence on the effective principal quantum number for the nd 1
D
2 series is analyzed and compared with the quantum defect dependence.
Received 25 February 2000 and Received in final form 26 July 2000 相似文献
10.
Z. H. Yang S. B. Du X. T. Zeng H. W. Chang B. L. Zhang K. X. Zhu D. Y. Yu X. H. Cai 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):33-36
Spectra for Δn = 0 transitions of the type
2s22pk-2s2pk+1 or 2s2pk-2pk+1 from highly ionized
sulfur produced in beam-foil excitation are investigated and compared to
similar spectra measured with other types of light sources. In the
experiment, fifty lines have been identified, of which eleven lines are new
and accurately measured. Analysis of spectra was based on comparisons with
other experimental results and calculated values. 相似文献
11.
R. Mayo J. Campos M. Ortiz H. Xu S. Svanberg G. Malcheva K. Blagoev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):169-173
We report on radiative lifetimes of 4d5p excited states
of Zr III produced in a laser produced plasma. The ions were
populated either in the ground state or in metastable states, and
the number of ions is strongly dependent on the application of an
external magnetic field, which is shown to be very important when
using the time-resolved laser-induced fluorescence technique for
lifetime measurements in highly charged ions. The experimental
lifetime results fall in the region 1–2 ns with statistical
uncertainties less than 7%. The experimental values were compared
with multi-configuration Hartree-Fock calculations showing an
agreement within 12–20%. The experimental values are systematically
higher than the theoretical ones. 相似文献
12.
C. Z. Dong S. Fritzsche B. Fricke 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(3):317-323
Recent high precision measurements on the lifetime of
the metastable 6s[3/2]2 state of atomic xenon display a
difference with previous predictions by a factor of 2–3. In the
present work, a systematic relaxation and correlation approach,
which has been developed on the basis of a widely used
multi-configuration Dirac-Fock method, is applied to study the
electric dipole allowed E1 and forbidden M1, E2 and M2 transitions
between the 5p5 6s and
5p6 configurations. We systematically include the correlation effects
which arise from all the single and double excitations from the
occupied
shells into the
(n=6–10) active sets and the relaxation effects caused by change
of the electron density between the radiative initial- and final-states. This study not only reduces greatly the existing
discrepancy in the lifetime of the 6s[3/2]2 state, but also
presents rather consistent results for both the lifetime of the
metastable 6s'[1/2]0 state and the oscillator strength of the
5p5 6s - 5p6 E1 resonant transitions. 相似文献
13.
S. Djeniže A. Srećković S. Bukvić 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(1):11-16
We have obtained transition probabilities (Einstein's A values) of thirteen transitions in doubly (N III), six in triply (N IV) and two in four times (N V) ionized nitrogen spectra
belonging to the 3s-3p and 3p-3d transitions using a relative line intensity ratio (RLIR) technique. The linear low-pressure pulsed arc was used as an optically
thin plasma source operated at 51 400 K electron temperature and 2.2×1023 m-3 electron density in nitrogen plasma. Our A values are compared to recent theoretical and experimental data.
Received 18 December 2001 / Received in final form 29 January 2002 Published online 28 June 2002 相似文献
14.
C. Vadla V. Horvatic K. Niemax 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):23-25
The “forbidden” Pb 6p2
3P
0
↦6
p
2
3P1 line at 1278.9 nm is measured by diode laser absorption in a resistively heated hot-pipe filled with a lead vapour and argon
as buffer gas. The measurements performed at a temperature of 1170 K and a lead number density of 2.4×10
15
cm-3 yield the oscillator strength f
F
= (4.5±1.1)×10
-7
which corresponds to a radiative transition probability A
F
= (6.1±1.5) s-1. Within the error bars, the result is in agreement with theoretical data published by different authors.
Received 11 October 2000 and Received in final form 5 January 2001 相似文献
15.
S.G. Nakhate Sheo Mukund S. Bhattacharyya 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(3):394-225
Radiative lifetimes of 20 odd-parity excited energy levels in Zr I, out of which 10 for the first time, have been investigated in the energy range 17 400-29 300 cm−1. The levels belong to the 4d25s5p and 4d35p electronic configurations. Time-resolved laser-induced fluorescence spectroscopy technique in supersonic free-jet has been employed in the present work to circumvent the effects of collision in lifetime measurements. 相似文献
16.
A. Johansson M.K. Raarup Z.S. Li V. Lokhnygin D. Descamps C. Lyngå E. Mevel J. Larsson C.-G. Wahlström S. Aloise M. Gisselbrecht M. Meyer A. L'Huillier 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(1):3-11
A pump-probe technique has been applied for measuring the lifetimes and absolute photoionization cross-sections of excited
He states. The 1s2p 1P and 1s3p 1P states of He are excited by using the 13th and the 14th harmonic, respectively, of a tunable 70 ps dye laser generated in
a Kr gas jet. The states are ionized after a varying time delay, by absorption of probe photons with energies between 1.6
and 4.5 eV. Lifetimes of τ(1s2p) = 0.57 ns and τ(1s3p) = 1.76 ns are determined with a precision of about 15%. A significant enhancement of the number of ions present in the lifetime
curves at zero time delay for pressures above 6×10-5 mbar is attributed to direct two-photon ionization of He in combination with AC Stark broadening of the excited state and
absorption of the XUV light in the medium. Absolute photoionization cross-sections from the He 1s2p 1P and He 1s3p 1P states in the threshold region are determined by measuring the saturation of the ionization process with a precision of
∼ 25%. In addition, the variation of the relative orientation between the polarization vectors of the pump and probe beams
enables the determination of partial photoionization cross-sections.
Received 3 June 2002 / Received in final form 14 August 2002 Published online 22 October 2002
RID="a"
ID="a"Present address: Department of Biophysics, Leiden University, 2333 CA Leiden, The Netherlands.
RID="b"
ID="b"Present address: Continuum Electro-Optics Inc., 3150 Central Expressway, Santa Clara, CA 95051, USA.
RID="c"
ID="c"Present address: CEA/DRECAM/SPAM, CEN Saclay, 91105 Gif-sur-Yvette, France.
RID="d"
ID="d"Present address: Department of Physics, National University of Rwanda, Butare, Rwanda.
RID="e"
ID="e"Present address: CELIA, Université Bordeaux 1, 33405 Talence, France.
RID="f"
ID="f"Present address: MAX-Lab, Lund University, Box 118, 221 00 Lund, Sweden.
RID="g"
ID="g"e-mail: anne.lhuillier@fysik.lth.se 相似文献
17.
R. González-Férez P. Schmelcher 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):189-199
We investigate the effects of a magnetic field with low to intermediate strength on several spectroscopic properties of the
sodium atom. A model potential is used to describe the core of sodium, reducing the study of the system to an effective one-particle
problem. All states with principal quantum numbers n = 3, 4, 5, 6 and 7 are studied and analysed. A grid of twenty values for the field strength in the complete regime B = 0 - 0.02 a.u. is employed. Ionisation energies, transition wavelengths and their dipole oscillator strengths are presented.
Received 5 November 2002 Published online 4 February 2003 相似文献
18.
Zs. Podolyák P.G. Bizzeti A.M. Bizzeti-Sona S. Lunardi D. Bazzacco A. Dewald A. Algora G. de Angelis E. Farnea A. Gadea D.R. Kasemann T. Klug Th. Kröll S. Lenzi D.R. Napoli C.M. Petrache R. Peusquens C. Rossi Alvarez T. Martinez C.A. Ur 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):29-36
Lifetimes of excited states in 148Gd were measured using the recoil distance method with a plunger device coupled to the EUROBALL Ge detector array. The differential
decay curve method in coincidence mode allowed the unambiguous determination of lifetimes of more than 20 excited states.
The obtained transition strengths are in good agreement with the shell model calculations. The effect of the Z = 64 subshell closure on the B(E2 : 2+ → 0+) reduced strengths above the N = 82 magic number is discussed.-1
Received: 14 November 2002 / Accepted: 4 February 2003 / Published online: 29 April 2003 相似文献
19.
H. Nilsson L. Engström H. Lundberg P. Palmeri V. Fivet P. Quinet É. Biémont 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(1):13-19
New measurements of radiative lifetimes for 9 levels in singly ionized tungsten (WII) have been performed with the time-resolved laser-induced-fluorescence technique. Transition probabilities have been obtained
from a combination of experimental lifetimes and theoretical branching fractions. The reliability of the present results is
assessed through the good agreement observed between the calculated lifetimes and the experimental values from this work and
from previous publications. These new results fill in a gap in the available data for this atomic species particularly important
for fusion reactors. 相似文献
20.
A. Bacławski T. Wujec J. Musielok 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):195-199
Intensities of 15 intersystem transitions and 5 LS allowed multiplets of neutral nitrogen
(NI) from infrared part of the spectrum were measured by emission spectroscopy method.
All allowed as well as LS-forbidden spectral lines belong to the 3p-3d transition array.
The nitrogen spectra were excited in a wall-stabilized high-current arc ran in helium with small
admixture of nitrogen. On the basis of these line (multiplet) intensity measurements, transition
probabilities of 15 intersystem lines were determined relative to transition probabilities of
appropriately chosen allowed multiplets. Finally the relative data for intersystem transitions were normalized to an absolute
scale by applying reference multiplet strength values recommended by the Atomic Spectroscopy Group of NIST. The determined
line strengths are compared with available calculated and — in the case of 5 transitions — also with experimental data. 相似文献