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1.
P.?Mas?owski K.?Bielska A.?Cygan J.?Domys?awska D.?Lisak R.?Ciury?o A.?Bielski R. S.?Trawiński 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(3):295-302
Careful analysis of the intercombination 51S0–53P1 line of the 113Cd isotope with two hfs components
and was carried out.
The hyperfine splitting of this line was determined to uncertainty less than
10-3 cm-1 using neon-perturbed Doppler limited spectra. 相似文献
2.
A. Nadeem M. Nawaz S. U. Haq S. Shahzada M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(2):147-151
We report term energies and quantum defects of highly excited even-parity states of mercury in the 83 876–84 140 cm-1 energy range, employing a two-step laser excitation scheme via the S0↦6s6p3P1 inter-combination transition. Two dye lasers, pumped by a common Nd:YAG laser, were frequency doubled by BBO crystals and
used to record the spectra in conjunction with a thermionic diode ion detector. Our new observations include the much extended
D2 (22 ≤n ≤52) series and a few members of the S1 (24 ≤n ≤30) Rydberg series. Members of the D2 Rydberg series with such a high n value are reported for the first time. The relative intensities of the D2 and S1 transitions (m = 4, 5 and 6) of group II-B elements excited from the P1 inter-combination states are also discussed. 相似文献
3.
Z. W. Liu X. F. Yang A. M. Zhu G. L. Zhao Y. Xu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(3):365-373
The hydroxyl radical (OH) plays an important role in combustion systems,
atmospheric chemistry and the removal of air pollutants by non-thermal
plasmas. The present work reports the determination of the hydroxyl radicals
in atmospheric dielectric barrier discharge plasmas via near infrared
continuous wave cavity ring-down spectroscopy. The P-branches of OH
X2Πi (ν' = 2 ←ν′′ = 0) bands were used for its number density measurements. The minimum measurable absorption coefficient is about
3 × 10-8 cm-1 in DBD plasmas. At certain experimental
conditions (a.c. frequency of 70 kHz, 6700 ppm H2O in He, 1 atm), when
the peak-to-peak discharge voltage varied from 6 kV to 10.4 kV, the
determined OH radical concentration increased from (2.1 ± 0.1) ×
1013 molecules cm-3 to (3.7 ± 0.1) × 1013 molecules cm-3. The plasma gas temperature, derived from the Boltzmann plots of OH rotational population distributions, ranged from 312
± 10 K to 363 ± 10 K when the discharge voltage was raised in the above range.
The influences of O2 and N2 addition on the production of OH
radicals have been also investigated. 相似文献
4.
A. Fielicke G. Meijer G. von Helden 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):69-72
Infrared spectra in the range of 530–1400
cm–1 are presented for tantalum oxide
cluster cations
(x = 3, 4 and 6). These spectra are
obtained via multiple photon
dissociation (MPD) spectroscopy of free cluster cations moving
in a molecular beam. The IR spectra for
are compared to spectra of
as well as to the experimental data
available for vanadium oxide cluster cations from IR-MPD
spectroscopy. For
and
the IR spectra exhibit very strong
similarities (including the band positions), whereas absorption
bands in
are relatively blue-shifted by
about 20–40 cm–1. 相似文献
5.
We present new experimental data on the highly excited levels in mercury using the two-step laser excitation and optogalvanic detection technique in conjunction with a RF discharge cell. The 6s7s 3S1 intermediate level has been accessed from the 6s6p 3P2 metastable level that is collisionally populated in the mercury discharge in the presence of a buffer gas at a pressure of about 1 Torr. Two beams fromtwo different dye lasers pumped with a common excimer laser were passed through the discharge cell containing mercury vapors. The first laser was tuned to 6s7s 3S1 level whereas the second laser was scanned covering the wavelength region between 544-458 nm. We have observed the 6snp 3P0 (
), 6snp
(
), 6snp
(
) and 6snp
) Rydberg series. The 6snp
Rydberg series to such high n-value has been reported for the first time. The first ionization potential of mercury is determined from the 6snp
Rydberg series as 84184.15
0.05 cm-1. Some collisionally induced parity forbidden transitions have also been located that are identified as 6sns
(
) series.Received: 5 November 2003, Published online: 20 January 2004PACS:
31.50.-x Potential energy surfaces - 32.30.Jc Visible and ultraviolet spectra - 32.80.Rm Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states) 相似文献
6.
T. Müller M. Gilowski M. Zaiser P. Berg Ch. Schubert T. Wendrich W. Ertmer E. M. Rasel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):273-281
We present a compact and transportable inertial sensor for
precision sensing of rotations and accelerations. The sensor consists
of a dual atom interferometer operated with laser-cooled 87Rb.
Raman processes are employed to coherently manipulate the matter
waves. We describe and characterize the experimental apparatus. A
method for passing from a compact geometry to an extended
interferometer with three independent atom-light interaction zones is
proposed and investigated. The extended geometry will enhance the
sensitivity by more than two orders of magnitude which is necessary
to achieve sensitivities better than 10-8rad/s/. 相似文献
7.
Q. L. Lu Q. Q. Luo A. F. Jalbout J. G. Wan G. H. Wang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(2):219-223
Density functional theory has been employed in order to investigate the structure and stability of Si@Al12Hn () clusters. Hydrogenated Si@Al12 clusters exhibit pronounced stability for even numbers of H atoms. Large binding energy, HOMO-LUMO gaps and increased ionization
potentials imply that these clusters should be physically and chemically stable. The analysis of the charge density of the
HOMO plot illustrates that a pair of hydrogen atoms prefer to occupy opposing on-top sites for clusters with an even n number.
Studies of deformation charge density plots demonstrate that significant charge transfer occurs from the Si@Al12 to the H atoms. 相似文献
8.
We describe a new continuous wave cavity ringdown spectroscopy (cw-CRDS) approach using an extended cavity diode laser (ECDL)
optically self-locked to a high finesse cavity including an intracavity glass plate under the Brewster angle. Low noise, mode-by-mode
absorption spectra are recorded at a high acquisition rate (laser frequency scan greater than 400 GHz/s) and covering four
orders of magnitude in absorption coefficient. Sampling spectra with the fixed high finesse cavity frequency comb provides
high precision frequency markers. An original scheme for the laser beam shut-down, based on signal shape analysis and the
diode laser injection current control, is presented. This scheme avoids any supplementary switching device. To retrieve ringdown
processing at a kilohertz rate several exponential decay fit algorithms are compared. Performances of this new scheme are
demonstrated with the observation of very weak lines of the oxygen B-band around 680 nm. Atmospheric spectra of isolated lines
averaged for less than 10 s show a baseline noise of 5×10-10 cm-1 and a single point minimum detectable absorption loss over a one-second measurement interval of 2×10-10 cm/ is obtained.
PACS 07.88.+y; 42.55.Px; 42.62.Fi 相似文献
9.
I. D. Petrov V. L. Sukhorukov M. W. Ruf H. Hotop 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):289-302
Absolute photoionization cross sections for Ne atoms in the excited
levels (Paschen notation
) were calculated at near threshold energies within
the configuration interaction Pauli-Fock approach including core polarization.
The computed spectra and the lineshape parameters of the odd parity
2p1/2
5ns′/d′ autoionizing resonances are
found to be in good agreement with high resolution laser spectroscopic
results. Guided by the theoretical results, improved analyses of the measured
spectra by superimposed Fano-type profiles were achieved. Theoretical
predictions are presented for resonances which have not yet been studied
experimentally. In addition, we report the absolute partial photoionization
cross sections for the 2P3/2 and 2P1/2 channel at
photoelectron energies up to 7 eV. Except for the highest lying 2p1(1S0) level, these cross sections monotonically decrease with
energy (as reported earlier in single-electron calculations for the
Ne(2p53p) configuration) with branching ratios which essentially reflect
the core composition of the 2px levels. For the 2p1 level the resonance structure and the
partial cross sections are strongly influenced by a
Cooper-Seaton minimum in the d3/2
′ channel,located just above the 2P1/2 ionization limit. 相似文献
10.
J. Lecointre D. S. Belic J. J. Jureta R. Janev P. Defrance 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(3):265-278
Absolute cross sections for electron-impact dissociative excitation and
ionization of CD+
4 leading to formation of ionic products (CD2+
4, CD+
3, CD+
2, CD+, C+, D+
3, D+
2, and D+) have been measured. The animated crossed-beams
method is applied in the energy range from the reaction threshold up to 2.5 keV. Around 100 eV, the maximum cross sections
are found to be (3.8±0.2) ×10-19 cm2,
cm2,
(7.1±0.8) ×10-17 cm2, (9.0±0.8) ×
10-17 cm2 and (3.7±0.4) ×10-17 cm2 for the
heavy carbonaceous ions CD2+
4, CD+
3, CD+
2, CD+ and C+ respectively. For the light fragments, D+
3, D+
2, and D+, the cross sections around the maximum are
found to be (5.0±0.6) ×10-19 cm2, (1.7±
0.2) ×10-17 cm2 and (10.6±1.0) ×10-17 cm2, respectively. The cross sections are presented in closed analytic
forms convenient for implementation in plasma simulation codes. The analysis
of ionic product velocity distributions allows determination of the kinetic
energy release distributions which are seen to extend from 0 to 9 eV for
heavy fragments, and up to 14 eV for light ones. The comparison of present
energy thresholds and kinetic energy release with available published data
gives information about states contributing to the observed processes.
Individual contributions for dissociative excitation and dissociative
ionization are determined for each detected product. A complete database
including cross sections and energies is compiled for use in fusion
application. 相似文献
11.
We propose a scheme for producing high gain recombination X-ray lasers on hydrogen-like Balmer transitions by irradiating fibre targets with a 2 ps Chirped Pulse Amplification CPA beam of a Nd-glass laser facility. Very high gain coefficients for H-like C, N, O, F, Na Balmer transitions are predicted. The optimum electron density and temperature for maximum gain operation scale approximately asN
e 4 × 1013
Z
7 cm–3 and Te 7 × 10–3
Z
4 eV, respectively, at the time when maximum lasing gain appears. Significant improvement in gain performance of recombination X-ray lasers is predicted by using CPA ps pulse drivers. 相似文献
12.
M. -G. Porquet A. Astier Ts. Venkova A. Prévost I. Deloncle F. Azaiez A. Buta D. Curien O. Dorvaux G. Duchêne B. J. P. Gall F. Khalfallah I. Piqueras M. Rousseau M. Meyer N. Redon O. Stézowski R. Lucas A. Bogachev 《The European Physical Journal A - Hadrons and Nuclei》2009,39(3):295-306
The 81, 82, 83, 85Se nuclei have been produced as fission fragments in the fusion reaction 18O + 208Pb at 85MeV bombarding energy and studied with the Euroball IV array. Their high-spin level schemes have been built from the
triple -ray coincidence data and - angular correlations have been analyzed in order to assign spin and parity values to many observed states. The lowest-spin
states of the two-neutron and three-neutron configurations are strongly mixed with two-proton excitations among the fp orbits. On the other hand, the highest-spin states of these neutron configurations are found to remain almost pure. Neutron
excitation across the N = 50 gap is observed both in 83Se49 and in 85Se51 . 相似文献
13.
R. Hakalla R. Kępa W. Szajna M. Zachwieja 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(3):481-488
Three bands of the A1Π- X1Σ+ system
in the 12CH+ ion radical have been rephotographed under
high resolution as an emission spectra using a Geissler-type
discharge tube. The conventional technique of spectroscopy has
been implemented. Using the Th lines as a standards, as well as an
interferometric comparator equipped with a photoelectric scanning
device, the 0-0 , 0-1 and 2-1 bands have been
reanalyzed. By means of much longer bands (Jmax = 17 in the
Q(J) branch of the 0-0 band; Jmax = 16 in the R(J)
branch of the 0-1 band; Jmax = 14 in the P(J) and
Q(J) branches of the 2-1 band), than have been observed so
far, as well as the merged calculations, using another five bands
given by Carrington et al. [A. Carrington, D.A. Ramsay, Phys.
Scripta 25, 272 (1982)] additionally, more accurate molecular
constants for the X1Σ+ state, the improved reduced
band system origin Te = 24118.726 (14) cm-1 as well as for
the first time the equilibrium molecular constants with their one
standard deviation for the A1Π state in the CH+ molecule
have been computed: ωe'=1864.402(22),
ωexe'=115.832(14), ωeye'= 2.6301(24),
Be'=11.88677(72), αe'= 0.9163(18), γe'=
-2.29(12)×10-2, εe'= 4.95(20)×10-3,
De'=1.92960(31)×10-3, βe'=
1.0733(50)×10-4, δe'= -1.312(16)×10-5,
, αqe'=
-3.14(16)×10-3, and qDe'= -2.20(14)×10-5
cm-1. Only in our research the addition to the zero-point
energy Y'00=-1.9430 cm-1 and
cm-1
have been calculated. The equilibrium bond lengths of
r'e=1.235053(37) ? and
? for the
A1Π and X1Σ+ states, respectively have been
computed. Full quantum-mechanics characteristic of the A-X
bands system in the 12CH+ molecule, i.e. RKR turning
points, the Franck-Condon factors and r-centroids have been
obtained. Dissociation energies DeX1 Σ+=(38470±
3503) cm-1 and DeA1 Π= (14415 ±3509) cm-1
for the molecule under consideration have been estimated. 相似文献
14.
K. Ohshimo F. Misaizu K. Ohno 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):339-342
Cluster anions of a sodium atom with acrylonitrile
molecules,
(n = 0–6), have been studied by
negative-ion photoelectron spectroscopy. In addition,
theoretical calculations by using density functional theory have
been performed to obtain optimized structures and vertical
detachment energies. For Na(AN)–, the
spectrum can be explained by excitation of two different isomers
of the anion. For
, a broad band is found in the
photoelectron spectrum, whose profile is almost identical with
those of previously reported photoelectron spectra of
and a negative ion of chemically
synthesized 1,3,5-cyclohexanetricarbonitrile (CHTCN) molecule.
From this resemblance of band profiles, we conclude that
oligomerization of (AN)3 takes place in
and the CHTCN is formed as the
intracluster reaction product. 相似文献
15.
J. Sauvage J. Genevey B. Roussière S. Franchoo A. N. Andreyev N. Barré J. -F. Clavelin H. De Witte D. V. Fedorov V. N. Fedoseyev L. M. Fraile X. Grave G. Huber M. Huyse H. B. Jeppesen U. K?ster P. Kunz S. R. Lesher B. A. Marsh I. Mukha J. Oms M. Seliverstov I. Stefanescu K. Van de Vel J. Van de Walle P. Van Duppen Yu. M. Volkov 《The European Physical Journal A - Hadrons and Nuclei》2009,39(1):33-48
The /EC decay of 189m, gPb has been studied at the ISOLDE facility using nuclear spectroscopy and in-source laser spectroscopy. A level scheme of
189Tl has been built from - coincidence relationships and information on the feeding of some excited levels of 189Tl provided by the hyperfine spectra obtained from laser ionization. The half-lives of both the 13/2+ and 3/2-
189Pb isomers have been estimated to be T
1/2 = 50±3 s and T
1/2 = 39±8 s, respectively. Calculations have been performed for different oblate and prolate nuclear deformations using an axial-rotor
coupled to one-quasiparticle model, a structure has been suggested for the low-lying levels of the 189Tl nucleus. 相似文献
16.
Xiang Liu Zhi-Gang Luo Yan-Rui Liu Shi-Lin Zhu 《The European Physical Journal C - Particles and Fields》2009,61(3):411-428
We perform a systematic study of the possible molecular states composed of a pair of heavy mesons such as
,
,
in the framework of the meson exchange model. The exchanged mesons include the pseudoscalar, scalar and vector mesons. Through
our investigation, we find the following results. (1) The structure X(3764) is not a molecular state. (2) There exists strong attraction in the range r<1 fm for the
system with J=0,1. If future experiments confirm Z
+(4051) as a loosely bound molecular state, its quantum number is probably J
P
=0+. Its partner state Φ
**0 may be searched for in the π
0
χ
c1 channel. (3) Vector meson exchange provides strong attraction in the
channel together with pion exchange. A bound state solution may exist with a reasonable cutoff parameter Λ∼1.4 GeV. X(3872) may be accommodated as a molecular state dynamically although drawing a very definite conclusion needs further investigation.
(4) The
molecular state may exist. 相似文献
17.
S. I. Tkachenko V. M. Romanova A. R. Mingaleev A. E. Ter-Oganesyan T. A. Shelkovenko S. A. Pikuz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):335-341
Experimental results on electrical explosion of wires in vacuum with current density A/m2, current rise rate (dI/dt) ~ 50 A/ns and current pulse with amplitude ∼10 kA are presented. The structure of the discharge
channels in vacuum has been studied using laser shadow and schlieren imaging with 7 ns frames, UV pinhole images with 5 ns
frames and X pinch X-ray backlighting. The information on the dense core material and the conducting plasma distributions
was obtained in our experiments by analyzing and comparing the results obtained from all diagnostics. 相似文献
18.
We have performed a series of experiments to observe 11 Stark-induced E1 transitions from the 15650.55 cm-1 level to higher levels with odd parity in samarium (Sm) with optical double-resonance technique. Five Stark-induced E1 transition to the 28233.08, 28613.22, 28913.97, 29041.31 and 29130.03 cm-1 levels have been observed. In order to investigate the contributors to the Stark-induced E1 transition, we have measured scalar and tensor polarizabilities for the observed Stark-induced E1 transitions. Clear Stark splittings were observed for the levels 28233.08 and 28613.22 cm-1, and their tensor polarizabilities were determined for each isotope. Scalar polarizabilities were determined for the 28233.08, 28613.22, 28913.97 and 29130.03 cm-1 levels for the first time. Among them, scalar polarizability for the 28233.08 cm-1 level was the largest in magnitude and was 3.60(10) x 103 kHz/(kV/cm)2 for
Sm. We noticed that both scalar and tensor polarizabilities of the 28233.08 cm-1 level depend on the isotope; the difference of magnitude of the scalar and tensor polarizabilities between
Sm and
Sm were remarkably large and were about 10 and 6 percent, respectively.Received: 10 February 2003, Published online: 30 July 2003PACS:
32.60.+i Zeeman and Stark effects - 32.10.Dk Electric and magnetic moments, polarizabilityD. Angom: Present address: Physical Research Laboratory, Navarangpura, Ahmedabad 380 009, India. 相似文献
19.
A.?Sibirtsev J.?Haidenbauer F.?Huang S.?Krewald U.?-G.?Mei?ner 《The European Physical Journal A - Hadrons and Nuclei》2009,40(1):65-75
We present a systematic analysis of backward pion photoproduction for the reactions
p
p and
p
n . Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision
with older data on - and -photoproduction at = 180° indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around ≃ 3 GeV. In the energy region of
2.5 GeV, covered by the new measurements of
p
p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the
Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of
excited baryons. 相似文献