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101.
M. Sugawara Y. Toh T. Czosnyka M. Oshima T. Hayakawa H. Kusakari Y. Hatsukawa J. Katakura N. Shinohara M. Matsuda T. Morikawa A. Seki F. Sakata 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):409-414
Electromagnetic properties of the low-lying states in a 70Ge nucleus were studied through the multiple Coulomb excitation of a 70Ge beam with a natPb target. Relative γ-ray intensities were measured as a function of emission angle relative to the scattered projectile.
Sixteen E2 matrix elements, including diagonal ones, for 6 low-lying states have been determined using the least-squares search code
GOSIA. The expectation values 〈Q
2〉 of 01
+ and 02
+ states in 70Ge are compared with those in 72, 74, 76Ge. Simple mixing calculations indicate that the 02
+ states in 70Ge and 72Se can be treated as deformed intruder states. It is shown that the deformed intruder becomes the ground state in 74Kr. These interpretations of the 02
+ states in this region are compared with the potential-energy surface calculations by the Nilsson-Strutinsky model, which
allow to interpret the experimental results in a qualitative way from the theoretical point of view.
Received: 2 September 2002 / Accepted: 5 November 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: sugawara@pf.it-chiba.ac.jp
Communicated by D. Schwalm 相似文献
102.
T.?KunertEmail author R.?Schmidt 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,25(1):15-24
In Rydberg atoms subject to static and harmonic collinear electric fields, intrashell transition can be induced by the first
order perturbation from a small perpendicular electric or magnetic field, or by effects of the second order in the major fields.
Both mechanisms lead to resonances that are suppressed under certain conditions, and high-frequency interference oscillations
in case of non-adiabatic field switching. Recent measurements of microwave ionization signals show very rich and fascinating
structures similar to the ones predicted for intrashell mixing. We show that the observed ionization structures may be explained
by diabatic electric-field ionization and the consistent use of perturbation theory for intrashell mixing. In particular,
the dominant oscillation frequency is successfully interpreted in terms of interference between first and second order transition
amplitudes. New predictions are provided. The present approach gives a comprehensive picture of intrashell transitions, which
may be tested in future experiments designed to observe such transitions directly.
Received 2 May 2002 / Received in final form 23 September 2002 Published online 21 January 2003
RID="a"
ID="a"e-mail: Valentin.Ostrovsky@pobox.spbu.ru
RID="b"
ID="b"e-mail: horsdal@ifa.au.dk 相似文献
103.
A. Gopalan J. Bömmels S. Götte A. Landwehr K. Franz M.-W. Ruf H. Hotop K. Bartschat 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(1):17-29
A novel electron scattering apparatus for high resolution studies of angle-differential elastic and inelastic electron scattering
from atoms and molecules in the gas phase is described and its performance characterized. It combines a laser photoelectron
source, a triply differentially pumped collimated supersonic beam target (half angle 0.015 rad, background to beam density
ratio < 0.01), and several electron multipliers for simultaneous detection of elastically scattered electrons and metastable atoms (or
molecules) due to inelastic scattering. In detailed test measurements of the yield for the production of metastable He*(23S1) atoms around its threshold, the dependence of the overall energy width on various experimental parameters has been investigated.
So far a resolution down to 7 meV (FWHM) has been obtained. Under such conditions we have investigated the profile of the
He- (1
s
2
s
2
2
S
1/2
) resonance at the scattering angles 22
°
, 45
°
, and 90
°
. From a consistent fit of the measured profiles by resonant scattering theory we determine a new value for the resonance
energy ( E
r
= 19.365(1) eV) and an accurate resonance width ( Γ = 11.2(5) meV). These results are consistent with the previously recommended values.
Received 23 July 2002 Published online 29 October 2002
RID="a"
ID="a"e-mail: hotop@physik.uni-kl.de
RID="b"
ID="b"Permanent address: Department of Physics and Astronomy, Drake University, Des Moines, IA 50311, USA. 相似文献
104.
M. Fifirig A. Cionga F. Ehlotzky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):333-336
The two-photon ionization of the hydrogen atom from its ground state by a two-colour electromagnetic field consisting of two
odd harmonics of the same IR laser is analyzed. The influence of the state of polarization of the bichromatic field on the
azimuthal angular distribution and the dependence of the elliptic dichroism on the photon frequencies are reported.
Received 11 December 2002 Published online 29 April 2003
RID="a"
ID="a"e-mail: fritz.ehlotzky@uibk.ac.at 相似文献
105.
K.N. Joshipura M. Vinodkumar B.K. Antony N.J. Mason 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):81-90
Total ionization cross-sections of electron impact are calculated for the molecular targets CHx, CFx, SiHx, SiFx (x = 1-4) and CCl4 at incident energies 20-3 000 eV. The calculation is based on Complex Scattering Potential approach, as developed by us recently.
This leads to total inelastic cross-sections, from which the total ionization cross-sections are extracted by reasonable physical arguments. Extensive comparisons are made here with the previous theoretical
and experimental data. The present results are satisfactory except for the CFx and SiFx (x = 1-3) radicals, for which the experimental data are lower than most of the theories by more than 50%.
Received 23 May 2002 / Received in final form 24 October 2002 Published online 21 January 2003
RID="a"
ID="a"e-mail: knjoshipura@yahoo.com 相似文献
106.
107.
Carlson JW 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2000,147(2):210-216
A continuous transformation of an RF waveform with a modified Korteweg-de Vries equation or generalization can be used to adjust the phase behavior of a selective excitation pulse while preserving the magnitude behavior of the spin response. This transformation has applications in removing or adding to the nonlinear phase properties of a selected region. 相似文献
108.
R. Unanyan S. Guérin B. W. Shore K. Bergmann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(3):443-449
In traditional schemes of multilevel multilaser excitation, each laser pulse interacts with only one pair of states, and the
rotating wave approximation (RWA) is applicable. Here we study the population transfer process in a three-state system when
each of the two lasers interacts with each of the pair of states and when the Rabi frequencies characterizing the interaction
strengths of the system are comparable to or larger than the difference of the transition frequencies. We show that complete
and robust population transfer is possible under conditions more general than those hitherto considered necessary for stimulated
Raman adiabatic passage (STIRAP) or for successive π pulses. Using adiabatic Floquet theory we show that successful population transfer can be interpreted as adiabatic passage
by means of a transfer state which connects the initial and final states. The Floquet picture offers a convenient interpretation
of the population transfer as accompanied by multiple absorption of photons from or emission into the laser fields. 相似文献
109.
利用软X射线共振非弹性散射谱(resonant inelastic soft X-ray scattering, RIXS)对3d过渡金属硫化物中的硫化锰(MnS)电子结构进行了研究.通过分析Mn2+的2p63d5→2p53d6→2p63d5二次光子过程,得到了共振非弹性散射谱中的两类非弹性峰,d-d电子跃迁和电荷转移(charge-transfer)跃迁.这两部分跃迁分别共振增强于L边附近及伴随峰附近.基于Hartree-Fock方法的多重态计算分别模拟了原子近似下和立方体Oh对称群下共振非弹性散射谱及吸收谱.计算得MnS实际晶体场10Dq值介于0.80eV—0.85eV之间.对MnS和MnO CT跃迁差异的讨论表明MnS较强的CT跃迁来源于其较窄的能隙宽度.
关键词:
软X射线共振非弹性散射
软X射线吸收谱
d-d跃迁
电荷转移 相似文献
110.
研究了电子俘获材料CaS∶Eu,Sm多晶粉末的紫外-可见-红外吸收光谱及红外激励光谱.研究结果表明,CaS∶Eu,Sm中主激活剂Eu和辅助激活剂Sm分别以Eu2 离子和Sm3 离子的形式存在;ETM的吸收差谱及红外激励光谱所反映的光谱特性是不同的.紫外-可见光区的吸收差谱给出了ETM光谱存储灵敏度的信息,而红外光谱区的吸收差谱给出了ETM所俘获电子数量的信息及电子陷阱能级的特征(深度和宽度)信息.红外激励光谱则反映了ETM将不同波长的红外激励光的能量转换为特定波长处的红外辐射光能量的光谱转换灵敏度.二者结合起来可以更完整地描述ETM的光谱特性. 相似文献