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21.
M. Saleem N. Amin S. Hussain M. Rafiq S. Mahmood M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):277-283
New measurements of photoionization cross-sections of the lithium isotopes
are reported employing a Time of Flight (TOF) mass spectrometer in
conjunction with an atomic beam apparatus. Using a two-step selective
photoionization and saturation technique, we have simultaneously measured
the photoionization cross-section of the 2p excited state of both the
isotopes Li6 and Li7 as 15±2.5 Mb and 18 ±2.5 Mb
where as the corresponding number densities have been determined as
N0≈5.3×1010 atoms/cm3 and
N0≈6.2×1011 atoms/cm3 respectively. 相似文献
22.
Zhao Libo 《原子与分子物理学报》1995,(1)
VariationofSatelliteIntensityFactorswithninthe1s~2s∈lc→1s~23dnl→1s~2pnlDielectronicRecombinationofLithiumlikeIons¥ZhaoLibo(Ins?.. 相似文献
23.
N. Sauerwald J. Klinkmann T. Porwol G. Dmtr I. Hemmerich H. -J. Freund 《Journal of Electron Spectroscopy and Related Phenomena》1995,70(3):197-206
Angular resolved autoionization spectra after core to bound excitation of N2 adsorbed on Ni(110) are presented. The experimental autoionization spectra are compared with calculated spectra for the model system Ni---N---N by application of the many-body Green's function technique using SCF-MO-CNDO one particle wavefunctions. The angular dependences of the autoionization lines are explicitly calculated. The theoretical approach allows one to assign the spectra obtained after core to bound excitation including angular effects within the framework of molecular orbital theory. The assignment is compared with results for the CO on Ni(110) system. 相似文献
24.
类硼离子N2+光电离的R-矩阵理论计算 总被引:3,自引:2,他引:1
本文首次运用R-矩阵理论方法,分别在单通道近似和三态密耦近似下计算了离子N2+基态(1s22s22p) 2P的不同过程、不同分波的光电离截面及各分波的光电离截面随有效量子数的变化规律.在三态密耦近似下,由于大量的自电离态与连续态的相互作用,计算结果显示了光电离过程中非常丰富的Rydberg系列共振结构,是以前的理论计算中所从未涉及到的. 相似文献
25.
Hiroki Nakamura 《中国化学会会志》1995,42(2):359-366
Characteristics and dynamics of superexcited states of molecules are interpreted by emphasizing their significant roles in various molecular dynamic processes. The states are expected to open a new field of physics and chemistry; but because of their complexity, they should be investigated by using the possible multifarious means from the various view points. The interplays between theory and experiment and also between the two theories, dynamics theory and quantum chemistry, are crucial to reveal this world. More systematic studies are required for the superexcited states of polyatomic molecules. 相似文献
26.
S. Assimopoulos A. Bolovinos E. Luc-Koenig S. Cohen A. Lyras P. Tsekeris M. Aymar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,1(3):243-254
We report the even parity J
=4,5 autoionizing spectra of calcium below the 3d threshold, investigated by two-step laser excitation from the 3d4s metastables
through the 3d4p , intermediate states and subsequent optogalvanic detection. The 3d4s states are populated by electronic collisions in a d.c.
glow discharge sustained in a Ca heat-pipe. More than a hundred resonant transitions have been measured with an accuracy of
for the narrow ones using standard laser calibration techniques. The high lying levels are assigned to all expected autoionizing series. Moreover, some levels are observed. The theoretical interpretation is achieved by a combination of the nearly ab initio eigenchannel R-matrix and multichannel quantum-defect (MQDT) methods as well as by an empirical determination of the MQDT parameters in
the phase-shifted formulation. Theoretical energy level positions and excitation profiles are compared with the experimental
data confirming the identification of the observed structures. Strong mixing between series is found, while the ones do not couple with the series. Further insight into the strong channel mixing in the studied energy range is provided by a comprehensive review
of the excitation profiles in the vicinity of the 4p5p perturber as obtained from a number of intermediate levels used in the present and in earlier experiments. Systematic electron
correlation trends for series of , and are discussed.
Received: 20 November 1997 / Accepted: 15 January 1998 相似文献
27.
A.-S.F. Obada A.M. Abdel-Hafez M. Abdelaty 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(3):289-294
Phase properties of the field interacting with a two-level atom in a lossless cavity Jaynes-Cummings model, taking into account
the level shifts produced by Stark effect with an additional Kerr medium for one-mode are studied using the phase formalism
of Pegg and Barnett. It is shown in particular that phase properties of the field reflect the collapse and revival phenomena.
The results for the time evolution of the phase probability distribution and the phase fluctuations are obtained. The effect
of Stark shift on the phase properties in both the absence and presence of a Kerr medium is analyzed. Phase localization is
found for certain choice of the parameters.
Received: 27 March 1998 / Revised: 8 June 1998 / Accepted: 9 June 1998 相似文献
28.
29.
M. A. Kalyar S. Mahmood S.-U. Haq N. Amin M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):229-236
We report a systematic line shape analysis study of the 6p7p configuration
based 1P1, 3D1 and 3P1 autoionizing
resonances in barium using a Nd:YAG pumped dye laser system in conjunction
with a thermionic diode ion detector. The even parity isolated autoionizing
resonances have been approached via four intermediate states 6 snp
1P1 (6 ≤n ≤8) and 5d6p 1P1. A comparison of
the Fano parameters of the resonance profiles reveals that the width of an
autoionizing resonance is independent of the excitation path while the line
profile parameter changes with the selection of different intermediate
states. 相似文献
30.
T. Rander M. Lundwall A. Lindblad G. Öhrwall M. Tchaplyguine S. Svensson O. Björneholm 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(2):253-257
Resonant Auger spectra of O2 clusters excited at the O1s edge are reported. After excitation to the repulsive 1s-13σ* state, the resulting resonant Auger spectrum displays features that remain constant in kinetic energy as the photon energy
is detuned. The shift between known atomic fragment features and these features is consistent with that observed for atoms
and clusters in singly charged states in direct photoemission. These findings are strong evidence for the existence of molecular
ultrafast dissociation processes within the clusters or on their surface. 相似文献