[PDF]    http://dx.doi.org/10.3952/lithjphys.47416

Open access article / Atviros prieigos straipsnis

Lith. J. Phys. 47, 387–395 (2007)


COMPARISON OF TWO THEORETICAL METHODS FOR STUDYING 2–2 TRANSITIONS IN BERYLLIUM ISOELECTRONIC SEQUENCE
P. Bogdanovicha and H.-S. Choub
aInstitute of Theoretical Physics and Astronomy of Vilnius University, A. Goštauto 12, LT-01108 Vilnius, Lithuania
E-mail: pavlas@itpa.lt
bInstitute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan 202, Republic of China

Received 31 October 2007; accepted 21 November 2007

Theoretical investigation of characteristics of allowed dipole 2–2 transitions in beryllium isoelectronic sequence is performed applying two different theoretical methods: the relativistic many-body perturbation theory and the configuration interaction method. The data on oscillator strengths are obtained for ions with nucleus charge ranging from 4 till 29. The calculated data reveal a very good coincidence of these two methods almost for all investigated ions. The comparison of results of the present work with experimental and theoretical data of other authors for N III and Fe XXIII shows that the level of accuracy of the obtained oscillator strength values is high enough for interpretation of the experimental data as well as for modelling of the different types of plasma.
Keywords: configuration interaction, perturbation theory, beryllium isoelectronic sequence, 2–2 transitions
PACS: 31.15.Ar, 31.15.Mg, 31.25.Eb, 31.25.Jf, 32.70.Cs


DVIEJŲ TEORINIŲ METODŲ LYGINIMAS NAGRINĖJANT 2–2 ŠUOLIUS BERILIO IZOELEKTRONINĖJE SEKOJE
P. Bogdanovičiusa, H.-S. Choub
aVilniaus universiteto Teorinės fizikos ir astronomijos institutas, Vilnius, Lietuva
bNacionalinio Taivanio vandenyno universiteto Optoelektronikos mokslų institutas, Kylangas, Kinijos Respublika

Atliktas teorinis leistinų elektrinių dipolinių šuolių 2–2 tyrimas berilio izoelektroninei sekai. Branduolių krūviams nuo 4 iki 29 tyrimas atliktas dviem artiniais – konfigūracijų superpozicija ir trikdžių teorija. Gautas geras šuolių tikimybių ir osciliatorių stiprių, gautų skirtingais teoriniais metodais, tarpusavio sutapimas esant įvairiems jonizacijos laipsniams. Literatūros duomenų N III ir Fe XXIII jonams palyginimas su šio darbo rezultatais patvirtina pakankamai aukštą pastarųjų patikimumą.
Taip pat nurodytas esminis gautų osciliatorių stiprių nesutapimas su NIST duomenų bazės duomenimis kai kurioms B II, F VI ir Ne VII jonų linijoms.


References / Nuorodos


[1] E. Träbert and P.H. Heckmann, Beam-foil lifetimes of Be-like ions from Mg to S, Phys. Scripta 22, 489 (1980),
http://dx.doi.org/10.1088/0031-8949/22/5/011
[2] L. Engström, B. Denne, J.O. Ekberg, K.W. Jones, C. Jupén, U. Litzén, W.T. Meng, A. Trigueiros, and I. Martinson, Lifetimes of the 2s2p 1P level in Be-like N IV and O V obtained from beam-foil experiments and extensive cascade analyses, Phys. Scripta 24, 551 (1981),
http://dx.doi.org/10.1088/0031-8949/24/3/009
[3] J.P. Buchet, M.C. Buchet-Poulizac, A. Denis, J. Désesquelles, M. Druetta, J.P. Grandin, M. Huet, X. Husson, and D. Lecler, Radiative lifetimes and oscillator strengths for 2s–2p transitions in He-, Li-, and Be-like iron, Phys. Rev. A 30, 309, (1984),
http://dx.doi.org/10.1103/PhysRevA.30.309
[4] N. Reistad, R. Hutton, A.E. Nilsson, I. Martinson, and S. Mannervik, Lifetimes of levels in C II and C III, derived from beam-foil experiment and extensive cascade analyses, Phys. Scripta 34, 151 (1986),
http://dx.doi.org/10.1088/0031-8949/34/2/011
[5] M. Godefroid, J. Olsen, P. Jönsson, and Ch. Froese Fischer, Accurate multiconfiguration Hartree–Fock calculations of oscillator strengths in light atoms: The Boron (B II) line at 1362 Å, Astrophys. J. 450, 473 (1995),
http://dx.doi.org/10.1086/176157
[6] J. Fleming, T. Brage, K.L. Bell, N. Vaeck, A. Hibbert, M.R. Godefroid, and C. Froese Fischer, Systematic studies of N IV transitions of astrophysical importance, Astrophys. J. 455, 758 (1995),
http://dx.doi.org/10.1086/176621
[7] J. Fleming, N. Vaeck, A. Hibbert, K.L. Bell, and M.R. Godefroid, Oscillator strengths for the resonance line of ions in the beryllium isoelectronic sequence, Phys. Scripta 53, 446 (1996),
http://dx.doi.org/10.1088/0031-8949/53/4/006
[8] P. Jönsson, C. Froese Fischer, and E. Träbert, On the status and perspectives of MCDF calculations and measurements of transition data in the Be isoelectronic sequence, J. Phys. B 31, 3497 (1998),
http://dx.doi.org/10.1088/0953-4075/31/16/005
[9] U.I. Safronova, W.R. Johnson, M.S. Safronova, and A. Derevianko, Relativistic many-body calculations of transition probabilities for the 2l12l2[LSJ] – 2l32l4[LSJ′] lines in Be-like ions, Phys. Scripta 59, 286 (1999),
http://dx.doi.org/10.1238/Physica.Regular.059a00286
[10] S. Majumder and B.P. Das, Relativistic magnetic quadrupole transitions in Be-like ions, Phys. Rev. A 62, 042508 (2000),
http://dx.doi.org/10.1103/PhysRevA.62.042508
[11] I.M. Savukov and W.R. Johnson, Combined configuration-interaction and many-body-perturbation-theory calculations of energy levels and transition amplitudes in Be, Mg, Ca and Sr, Phys. Rev. A 65, 042503, (2002),
http://dx.doi.org/10.1103/PhysRevA.65.042503
[12] E. Träbert, E.J. Knystautas, G. Saathoff, and A. Wolf, EIV intercombination transition rates in Be-like nitrogen ions measuerd at heavy-ion storage ring, J. Phys. B 38, 2395 (2005),
http://dx.doi.org/10.1088/0953-4075/38/14/006
[13] P. Bogdanovich and R. Karpuškienė, Transformed radial orbitals with a variable parameter for the configuration interaction, Lithuanian Phys. J. 39, 193 (1999)
[14] P. Bogdanovich and R. Karpuškienė, Numerical methods of the preliminary evaluation of the role of admixed configurations in atomic calculations, Comput. Phys. Commun. 134, 321 (2001),
http://dx.doi.org/10.1016/S0010-4655(00)00214-9
[15] R. Karpuškienė, R. Karazija, and P. Bogdanovich, The average energy distance between two interacting configurations and its application for the investigation of CI in atoms, Phys. Scripta 64, 333 (2001),
http://dx.doi.org/10.1238/Physica.Regular.064a00333
[16] P. Bogdanovich, R. Karpuškienė, and A. Momkauskaitė, Some problems of calculation of energy spectra of complex atomic configurations, Comput. Phys. Commun. 143, 174 (2002),
http://dx.doi.org/10.1016/S0010-4655(01)00446-5
[17] P. Bogdanovich and A. Momkauskaitė, A program for generating configuration state lists in many-electron atoms, Comput. Phys. Commun. 157, 217 (2004),
http://dx.doi.org/10.1016/S0010-4655(03)00519-8
[18] P. Bogdanovich, R. Karpuškienė, and A. Momkauskaitė, A program of generation and selection of configurations for the configuration interaction method in atomic calculations SELECTCONF, Comput. Phys. Commun. 172, 133 (2005),
http://dx.doi.org/10.1016/j.cpc.2005.06.006
[19] P. Bogdanovich, Multiconfiguration approach in the study of atomic spectra, Lithuanian J. Phys. 44, 135 (2004),
http://dx.doi.org/10.3952/lithjphys.44204
[20] P. Bogdanovich, Modern methods of multiconfigurational studies of many-electron highly charged ions, Nucl. Instrum. Methods B 235, 92 (2005),
http://dx.doi.org/10.1016/j.nimb.2005.03.152
[21] P. Bogdanovich, D. Majus, and T. Pakhomova, Investigation of accuracy of configuration interaction for oxygen isoelectronic sequence, Phys. Scripta 74, 558 (2006),
http://dx.doi.org/10.1088/0031-8949/74/5/013
[22] H.-S. Chou, Relativistic many-body calculations of transition amplitudes for berylliumlike ions, Phys. Rev. A 62, 042507 (2000),
http://dx.doi.org/10.1103/PhysRevA.62.042507
[23] P. Bogdanovich, R. Karpuškienė, and I. Martinson, Ab initio wavelengths and oscillator strengths for Cl X, Phys. Scripta 67, 44 (2003),
http://dx.doi.org/10.1238/Physica.Regular.067a00044
[24] R. Karpuškienė and P. Bogdanovich, Two-electron transitions and their importance for lifetimes of levels of configuration 2p43p in K XI, J. Phys. B 36, 2145 (2003),
http://dx.doi.org/10.1088/0953-4075/36/11/301
[25] R. Karpuškienė, P. Bogdanovich, and A. Udris, Ab initio oscillator strengths and transition probabilities of transitions from 2s22p23l and 2s2p33l in S X, At. Data Nucl. Data Tables 89, 45 (2005),
http://dx.doi.org/10.1016/j.adt.2004.11.001
[26] P. Bogdanovich, R. Karpuškienė, and A. Udris, Ab initio oscillator strengths and radiative lifetimes for Ca IX, J. Phys. B 37, 2067 (2004),
http://dx.doi.org/10.1088/0953-4075/37/10/006
[27] P. Bogdanovich and R. Karpuškienė, Theoretical study of the overlaping configurations 2s2p53l and 2s22p44l in Ar X, J. Phys. B 38, 1557 (2005),
http://dx.doi.org/10.1088/0953-4075/38/10/013
[28] V. Jonauskas, P. Bogdanovich, F.P. Keenan, M.E. Foord, R.F. Heeter, S.J. Rose, G.J. Ferland, R. Kisielius, P.A.M. van Hoof, and P.H. Norrington, Energy levels and transition probabilities for boron-like Fe XXII, Astron. Astrophys. 455, 1157 (2006),
http://dx.doi.org/10.1051/0004-6361:20064822
[29] P. Bogdanovich, R. Karpuškienė, and O. Rancova, Influence of the two-electron transitions on the liftimes of excited levels in boron isoelectronic sequence, Phys. Scripta 75, 669 (2007),
http://dx.doi.org/10.1088/0031-8949/75/5/014
[30] A. Jucys, Fock equations in a multiconfiguration approach, Zh. Eksp. Teor. Fiz. [Sov. Phys. JETP] 23, issue 2(8), 129 (1952) [in Russian]
[31] C. Froese Fischer, The MCHF atomic-structure package, Comput. Phys. Commun. 128, 635 (2000),
http://dx.doi.org/10.1016/S0010-4655(00)00009-6
[32] http://physics.nist.gov/PhysRefData/contents-atomic.html
[33] A. Hibbert, CIV3 – A general program to calculate configuration interaction functions and electric dipole oscillator strenghts, Comput. Phys. Commun. 9, 141 (1975),
http://dx.doi.org/10.1016/0010-4655(75)90103-4
[34] A. Ynnerman and C. Froese Fischer, Multiconfigurational-Dirac-Fock calculation of the 2s2 1S0 – 2s2p 3P1 spin-forbidden transition for the Be-like isoelectronic sequence, Phys. Rev. A 51, 2020 (1995),
http://dx.doi.org/10.1103/PhysRevA.51.2020
[35] H.-S. Chou, Comments on "Relativistic many-body calculations of transition probabilities for the 2l12l2[LSJ] – 2l32l4[LSJ′] lines in Be-like ions", Phys. Scripta 64, 140 (2001),
http://dx.doi.org/10.1238/Physica.Regular.064a00140