Gültekin ÇELİK, Hamdi Şükür KILIÇ, Erhan AKIN

Azot Atomunda İki Foton Soğurma Tesir Kesitlerinin Hesaplanması

Bu çalışmada azot atomunda bazı ince yapı seviyeleri arasındaki geçişler için iki foton soğurma tesir kesitleri hesaplanmıştır. İki foton soğurma tesir kesiti ifadesi açısal katsayılara ve radyal geçiş integrallerine bağlı olarak verilir. Açısal katsayıların hesaplanmasında Racah yöntemi, radyal geçiş integrallerinin belirlenmesinde ise en zayıf bağlı elektron potansiyel model teorisi kullanılmıştır. Elde edilen sonuçların literatürle uyumlu olduğu görülmüştür.

Anahtar Kelimeler:

Azot atomu, iki foton soğurma tesir kesiti, en zayıf bağlı elektron potansiyel model teorisi

The Calculation of Two-Photon Absorption Cross-Sections in Nitrogen Atom

In this study, two-photon absorption cross-sections for transitions between some fine structure levels in nitrogen atom have been calculated. The expression for the two-photon absorption cross-section is given to be depend on the angular coefficients and radial transition integrals. The Racah method was employed in calculation of the angular coefficients and the weakest bound electron potential model theory was used to compute the radial transition integrals. It has been found that the results obtained are in good agreement with the literature.

Keywords:

Nitrogen Atom, two-photon absorption cross-section, the weakest bound electron potential model theory,

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1. Berrington, K.A., Burke, P.G., Dourneuf, M. Le., Robb, W. D., Taylor, K. T. and Lan, Vo Ky New version of the general program to calculate atomic continuum processes using the R-matrix method Comput. Phys. Commun. Vol.14, 5-6, 367-412 (1979)
2. Berrington, K.A., Burke, P.G., Butler, K., Seaton, M.J., Storey, P.J., Taylor, K.T. and Yan, Y. Atomic data for opacity calculations II. computational methods J. Phys. B: At. Mol. and Opt. Physics 20 23 6379-6397 (1987)
3. Cowan, R.D. The theory of atomic structure and spectra University of California Press Berkeley (1981)
4. Indelicato, P., Gorveix, O. and Desclaux, J.P. Multiconfigurational Dirac- Fock studies of two-electron ions II. radiative corrections and comparison with experiment J. Phys. B: At. Mol. and Opt. Physics 20 4 651-663 (1987)
5. Biredikhin, V.I., Galanin, M.D. and Genkin, V.N. Two-photon absorption and spectroscopy Sov. Phys. Usp. Vol. 16 No. 3 299-321 (1973)
6. Biraben, F., Cagnac, B. and Grynberg, G. Experimental evidence of two-photon transition without doppler broadening Phys. Rev. Lett. 32,643. (1974)
7. Bokor, J. Multiphoton ultraviolet spectroscopy of some 6p levels in Krypton Phys. Rev. A 21, 1453– 1459 (1979)
8. Lambropoulos, P. Topics on multiphoton processes in atoms advances in atomic and molecular physics Vol. 12 Acedemic Press New York (1976)
9. Chang,T.N. and Poe, R.T. Bull. Am. Phys. Soc. 19,1202. (1974) 10. Pindzola, M.S. Two-photon excitation of atomic Oxygen Phys. Rev. A 17, 1021 (1978)
11. Omidvar, K. Two-photon excitation cross section in light and intermediatea atoms in frozen-core Lscoupling approximation Phys. Rev. A 22 4 1576 (1980)
12. Omidvar, K. Errata: Two-photon excitation cross section in light and ıntermediate atoms in frozen-core ls-coupling approximation Phys. Rev. A 22 4 1576 (1984)
13. Condon, E.U. and Shortley, G.H. The theory of atomic spectra Cambridge University press Cambridge (1959)
14. Racah, G. Theory of complex spectra I Physical Review 62 438 (1942)
15. Racah, G. Theory of complex spectra II Physical Review 63 367 (1943)
16. Rohrlich, F. Sum rules for multiplet strenghts Astrophysical Journal 129 449 (1959)
17. Kuhn, H.G. Atomic spectra Academic Press New York (1969)
18. Wen, G.W., Wang, L.Y. and Wang, R.D. Calculation of matrix elements in the model potential theory of atomic structure Chinese Science Bulletin 36 547-550 (1991)
19. Zheng, N.W., Sun, Y.J., Wang. T., Ma, D.X., Zhang, Y. and Su, W. Transition probability of lithium atom and lithiumlike ıons with weakest bound electron wave functions and coupled equations International Journal of Quantum Chemistry 76 51-61 (2000)
20. Ralchenko, Yu., Jou, F.C., Kelleher, D.E., Kramida, A.E., Musgrove, A., Reader, J., Wiese, W.L., and Olsen, K. NIST Atomic spectra database (version 3.0.1), National Institute of Standards and Technology, Gaithersburg, MD (2005)
21. Gaigalas, G. and Fischer, C.F. Extension of The HF Program to partially filled F-subshells Comput. Phys. Commun. Volume 98, 1-2, 255-264 (1996).
22. Lindgard, A. and Nielsen, S.E Numerical approach to transition probabilities in the coulomb approximation: Be II and Mg II Rydberg series J .Phys. B 8 1183–1199 (1975)