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1.
In a recent paper [Pramana — J. Phys.
64, 129 (2005)] results have been presented for electron impact excitation collision strengths for transitions among the fine-structure
levels of the 2s22p6 and 2s22p53s configurations of Ni XIX. In this paper we demonstrate through an independent calculation with the relativistic R-matrix code that those results are unreliable and the conclusions drawn are invalid. 相似文献
2.
In this paper we present calculations of electron impact excitation collision strengths for transitions among the 89 fine-structure
levels of the 2s22p6, 2s22p53ℓ, 2s2p63ℓ, 2s22p54ℓ, and 2s2p64ℓ configurations of Ni XIX, for which flexible atomic code (FAC) has been adopted. Comparisons are made with the earlier available
results in the literature, and the anomalies observed have been discussed.
相似文献
3.
The close coupling R-matrix method is used to calculate cross-sections for photoionization of Mg III from its first three excited states. Configuration
interaction wave functions are used to represent two target states of Mg III retained in the R-matrix expansion. The positions and effective quantum numbers for the Rydberg series converging to the excited state 2s
22p
6
2
S
e of the residual ion, are predicted. 相似文献
4.
Collision strengths have been calculated for electron impact excitation of sodium-like TiXII for all 21 transitions amongst
its lowest seven states. Configuration interaction wave functions have been used to represent the target states. The standard
and no-exchangeR-matrix codes have been used to calculate the contribution of partial waves withL⩽8 andL>8 respectively. Collision strengths are tabulated at selected energies in the range 26 to 50 Ryd. Effective collision strengths
are tabulated for electron temperatures in the range logT
e=4.0 to logT
e=6.0, withT
e in K. This is the first detailed calculation on this ion in which the effects of exchange, channel couplings and short-range
correlation are taken into account. 相似文献
5.
Collision strengths for all the transitions between the 15 lowest states of neon-like Ni XIX have been calculated for electron
impact in the 80–140 Ry energy range. Configuration-interaction wavefunctions have been used to represent the target states.
The standardR-matrix code has been used to calculate the lower scattering partial waves (L≤9), while a no-exchange version of the same code has been used to compute efficiently the higher partial waves (L≥10). Effective collision strengths for 105 excitation transitions between the ground state 2s
22p
6
1
S
e and the 142s
22p
53l Rydberg states are tabulated for electron temperatures in the range logT=5.40 to logT=7.00, withT expressed in °K. 相似文献
6.
The R-matrix method is used to calculate the total photoionization cross-sections from the ground 2s
22p
6
1
S
e and the first three excited 2s
22p
53p
3,1
S
e states of Al IV, for photon energies ranging from the first ionization threshold to just above the second threshold of the
residual ion Al V. The two lowest LS terms of Al V − 2s
22p
5
2
P
0, 2s2p
6
2
S
e, 2s2p
6
2
S
e, represented by sophisticated configuration interaction wavefunctions, are included in the R-matrix calculation. The resulting cross-sections are affected by Rydberg series of resonances converging to the 2s2p
6
2
S
e excited threshold. 相似文献
7.
Liang Liang Shi-kun He Chao Zhou 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(16):2460-2464
The photoionization of the ground state of neon-like ions is investigated, and the autoionizing spectrum of 2s22p5 (2P1/2)ns,nd and 2s2p6 (2S1/2)np Rydberg series of Al IV is studied by using the Breit-Pauli Hamiltonian within the R-matrix theory combining with the QB method of Quigly-Berrington (Quigley L, Berrington K A, Pelan J. Comput Phys Commun 1998;144:225). We predict the autoionizing energy levels and widths of four Rydberg series of Al IV. 相似文献
8.
TheR-matrix method is used to calculate cross-sections for the photoionization of Ne-like Fe16+ from ground 2s
22p
61
S
e and excited states belonging to 2s2p
6 3l and 2s
22p
5 3l configurations. Configuration interaction wavefunctions are used to represent two target states of Fe17+ ion retained in theR-matrix expansion. The cross-sections are obtained as a function of kinetic energy (ε
k) of the ejected electron from 10 to 24 Ry. For low kinetic energy the cross-sections show series of Rydberg states which
converge onto2
S
e threshold Fe17+. The calculations are carried out in the LS coupling. 相似文献
9.
在双电子复合过程发生的能量范围内,发射X光子的原子过程除双电子复合过程外还有辐射复合、共振激发、共振复合以及直接激发原子过程.本文使用相对论组态相互作用方法计算了这些过程的截面,比较了在双电子复合过程发生的能量范围内这些原子过程的截面与双电子复合过程截面,探讨了这些过程对双电子复合过程的影响.研究结果表明,辐射复合截面随入射电子束能量的增大迅速减小,在双电子复合能量范围内几乎为一常数,可以作为本底来处理;共振激发和共振复合过程对双电子复合过程的影响可以忽略不计;当入射电子束能量高于靶离子的第一激发能时,电子碰撞直接激发截面与高Rydberg态的截面连成一片,随着入射电子束能量的增加,电子碰撞直接激发截面越来越大,这时必须考虑直接激发过程.使用相对论组态相互作用方法计算了类氖氙离子的双电子复合截面,其结果与已有的部分实验和理论结果很吻合. 相似文献
10.
在双电子复合过程发生的能量范围内,发射X光子的原子过程除双电子复合过程外还有辐射复合、共振激发、共振复合以及直接激发原子过程. 本文使用相对论组态相互作用方法计算了这些过程的截面,比较了在双电子复合过程发生的能量范围内这些原子过程的截面与双电子复合过程截面,探讨了这些过程对双电子复合过程的影响. 研究结果表明,辐射复合截面随入射电子束能量的增大迅速减小,在双电子复合能量范围内几乎为一常数,可以作为本底来处理;共振激发和共振复合过程对双电子复合过程的影响可以忽略不计;当入射电子束能量高于靶离子的第一激发能时,电子碰撞直接激发截面与高Rydberg态的截面连成一片,随着入射电子束能量的增加,电子碰撞直接激发截面越来越大,这时必须考虑直接激发过程. 使用相对论组态相互作用方法计算了类氖氙离子的双电子复合截面,其结果与已有的部分实验和理论结果很吻合. 相似文献
11.
N. Verma A. K.S. Jha M. Mohan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(2):235-241
Electron excitation collision strengths for the transitions from the ground
state to the fine-structure levels of the 3s23p53d and
3s23p63d configurations in Ni XI are calculated using the
Breit-Pauli R-matrix method. Configuration interaction wavefunctions have
been used to represent the target states. The relativistic effects are
incorporated in the Breit-Pauli approximation by including one-body mass
correction, Darwin, and spin-orbit interaction terms in the scattering
equations. Collision strengths are tabulated at selected energies in the
range 10 to 75 Rydberg. Effective collision strengths are determined by
integrating collision strengths by assuming a Maxwellian distribution of
electron energies. The effective collision strengths are listed over a wide
temperature range (2×104-1×107 K) applicable to
astrophysical plasmas. Our results are the only collision strengths and
effective collision strengths available for this ion. We believe that the
data calculated in this work will be useful in solar, astrophysical and
laser applications. 相似文献
12.
K. M. Aggarwal F. P. Keenan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):205-213
In a recent paper, Verma et al. [Eur. Phys. J. D 42, 235 (2007)] have reported results for energy levels, radiative rates, collision strengths, and effective collision
strengths for transitions among the lowest 17 levels of the (1s22s22p6)3s23p6, 3s23p53d and 3s3p63d configurations of Ni xi. They adopted the civ3 and R-matrix codes for the generation of wavefunctions and the scattering process, respectively. In this paper, through two
independent calculations performed with the
fully relativistic darc (along with grasp) and fac codes, we demonstrate that their results are unreliable. New data are presented and their accuracy is
assessed. 相似文献
13.
We present an integral formula for the universal R-matrix of quantum affine algebra U
q
with Drinfeld comultiplication. We show that the properties of the universal R-matrix follow from the factorization properties of the cycles in proper configuration spaces. For general g we conjecture that such cycles exist and unique. For U
q
we describe precisely the cycles and present a new simple expression for the universal R-matrix as a result of calculation of corresponding integrals. 相似文献
14.
We construct the tri-Hamiltonian structure of the two-dimensional Toda hierarchy using the R-matrix theory.Mathematical Subject Classifications (1991). 37K10. 相似文献
15.
Adrian Doicu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(3):466-3484
In this paper we analyze three methods for computing the total field in the near-zone region. These methods use the expansion of the scattered field outside the minimum circumscribing sphere, an integral representation of the scattered field and a vector spherical wave expansion of the near-zone field. Calculations of the total field within the circumscribing sphere are presented for dielectric prolate spheroids to compare the different methods. 相似文献
16.
ABSTRACTFor spectral diagnostics in the solar transition region under the collision–equilibrium condition, the method for electron density diagnostics by the collisional excitation is discussed in this paper. By using observed signal ratio of spectral lines produced by the oxygen VI ion, we discuss the electron density by this method. We find that this method is valid for a large region of signal ratio (from 2.001 to 4.162). We obtain that the electron density increases with increasing signal ratio of the oxygen VI doublet, and the plasma has an electron density on the order of magnitude of 106–107?cm?3. This discussion will be significant for study on spectral diagnostics of the solar transition region. 相似文献
17.
This paper calculates the electron impact excitation rate coefficients from the ground term 2s22p2 3P to the excited terms of the 2s22p2, 2s2p3, 2s22p3s, 2s22p3p, and 2s22p3d configurations of N II. In the calculations, multiconfiguration Dirac--Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments. 相似文献
18.
A specific quantum Lax operator, forming a quantum U
q
(sl
n) chain, is suggested. The intertwining R
L
L relation is proved. The invariant local 2+1-dimensional reformulation of the auxiliary linear problem for the L-operator is discussed. 相似文献
19.
20.
We investigate the h-deformed quantum (super)group of 2 × 2 matrices and use a kind of contraction procedure to prove that the n-th power of this deformed quantum (super)matrix is quantum (super)matrix with the deformation parameter nh. 相似文献