We report accurate wavelengths for the three most intense lines (resonance line: 1s21S0 - 1s2p 1P1, intercombination line: 1s2 1S0 - 1s2p 3P1 and forbidden line: 1s21S0 - 1s2s 3S1) along with wavelengths for the 1s2 1S0 - 1snp1P1 and 1S0 - 1snp3P2 (2 ≤ n ≤ 25) transitions in He-like systems (Z = 2 – 13). The first spectral lines that belong to the above transitions are established in the framework of the Screening Constant per Unit Nuclear Charge method. The results obtained agree excellently with various experimental and theoretical literature data. The uncertainties in wavelengths between the present calculations and the available literature data are less than 0.004Å. A host of new data listed in this paper may be of interest in astrophysical and laboratory plasmas diagnostic.
References
[1]
Gabriel, A. and Jordan, C. (1969) Monthly Notices of the Royal Astronomical Society, 145, 241-248. https://doi.org/10.1093/mnras/145.2.241
Porquet, D. and Dubau, J. (2000) Astronomy and Astrophysics Supplement, 143, 495-514. https://doi.org/10.1051/aas:2000192
[5]
Liedahl, D.A. (1999) X-Ray Spectroscopy in Astrophysics, EADN School Proceedings, 1997, In: Van Paradijs, J.A. and Bleeker, J.A.M., Eds., 189.
[6]
Porquet, D., Mewe, R., Raassen, A.J.J., Kaastra, J.S. and Dubau, J. (2001) Helium-Like Ions as Powerful X-Ray Plasma Diagnostics. X-Ray Astronomy 2000. ASP Conference Proceeding, Vol. 234, 121-127.
Beiersdorfer, P., Bitter, M., von Goeler, S. and Hill, K.W. (1989) Physical Review A, 40, 150. https://doi.org/10.1103/PhysRevA.40.150
[10]
Engström, L. and litzén, U. (1995) Journal of Physics B: Atomic, Molecular and Optical Physics, 28, 2565. https://doi.org/10.1088/0953-4075/28/13/010
[11]
Bartnik, A.E., Biémont, E., Dyakin, V.M., Ya Faenov, A., Fiedorowicz, H., et al. (1997) Journal of Physics B: Atomic, Molecular and Optical Physics, 30, 4453. https://doi.org/10.1088/0953-4075/30/20/009
[12]
Accad, Y., Pekeris, C.L. and Schiff, B. (1971) Physical Review A, 4, 516. https://doi.org/10.1103/PhysRevA.4.516
[13]
Safronova, U.I., Safronova, M.S. and Bruch, R. (1995) Journal of Physics B: Atomic, Molecular and Optical Physics, 28, 2803. https://doi.org/10.1088/0953-4075/28/14/005
[14]
Porter, R.L. (2006) Theory and Application of Helium and Helium-Like Ions in Astrophysical Environments. College of Art and Sciences, Lexington University of Kentucky, Lexington.
[15]
Sakho, I. (2017) Atomic Data Nuclear Data Tables, 97, 425-438. https://doi.org/10.1016/j.adt.2016.12.001
[16]
Sakho, I. (2018) Journal of Electron Spectroscopy and Related Phenomena, 222, 40-50. https://doi.org/10.1016/j.elspec.2017.09.011
[17]
Radzig, A.A. and Smirnov, M.B. (1985) Reference Data on Atoms, Molecules and Ions (Berlin: Springer) Moore E C 1971 Atomic Energy Levels (Natl. Stand. Ref. Data Ser. Natl. Bur. Stand. No. 35). U.S. GPO, Washington DC, Vol. 1, 4.
[18]
Arnaud, P. (1993) Cours de chimie physique. 3rd Edition, Dunod, Paris, Chapter 11, 88.
[19]
Herzberg, G. (1958) Proceedings of the Royal Society (London) A, 248, 309-332. https://doi.org/10.1098/rspa.1958.0246
[20]
Kramida, A., Ralchenko, Y., Reader, J. and NIST ASD Team (2018) NIST Atomic Spectra Database (ver. 5.6.1). National Institute of Standards and Technology, Gaithersburg. https://physics.nist.gov/asd
