User menu

Accès à distance ? S'identifier sur le proxy UCLouvain

Vibrational branching ratios for single-photon ionization of Na-2

Primary tabs

Rudolph, H. Urbain, Xavier [UCL]

We report on an ab initio study of the single-photon ionization of Na-2 from the electronic ground state (X(1) Sigma(g)(+)) and subsequent photodissociation of the resulting ion. The calculations are done as a function of of internuclear distance (R=4.5-7.5 a.u.) and for a range of photoelectron energies 0.25-10 eV. The electronic continuum wave functions are determined using the so-called iterative Schwinger method, which is an L(2) method based on a single-center expansion of all relevant operators and wave functions. A Cooper minimum is found in the k pi-continuum's p wave (l=1) around a photoelectron energy of approximately 4.5 eV. This does not, however, lead to significant observable implications for the total cross sections. The subsequent photodissociation of the Na-2(+) ions is calculated using a numerical Numerov method, based on previously calculated data for the molecular potential-energy curves and dipole matrix elements. The spectrum resulting from photodissociation of ions created via photoionization of a thermal distribution of Na-2 molecules is calculated and compared with the recent results of Kortyna et al. [Phys. Rev. A 50, 1399 (1994)]. Excellent agreement is found with the experimental values if the assumed initial temperature of the molecular beam is approximately 50 K, which is substantially colder than previously estimated.

Document type Article de périodique (Journal article) – Article de recherche
Publication date 1996
Language Anglais
Journal information "Physical review. A, Atomic, molecular, and optical physics" - Vol. 53, no. 6, p. 4111-4119 (1996)
Peer reviewed yes
Publisher American Physical Soc (College Pk)
issn 1050-2947
e-issn 1094-1622
Publication status Publié
Affiliation UCL - SC/PHYS - Département de physique
Links
  1. J. Weiner, Adv. At. Mol. Phys., 26, 209 (1989)
  2. Meijer H. A. J., Pelgrim T. J. C., Heideman H. G. M., Morgenstern R., Andersen N., Cross sections and coherence terms for associative ionization of two differently excited Na(3p) atoms, 10.1063/1.456152
  3. Meijer H A J, Schohl S, Muller M W, Dengel H, Ruf M -W, Hotop H, Electron spectrometric study of the internal energy distribution in Na2+for single beam associative ionization, 10.1088/0953-4075/24/16/014
  4. Nijland J H, Gouw J A de, Dijkerman H A, Heideman H G M, Cross sections and coherences for energy pooling reactions between two Na*(3p) atoms, 10.1088/0953-4075/25/12/013
  5. Nijland J H, Blange J J, Rudolph H, Dijkerman H A, Heideman H G M, Energy pooling reactions between two Na* (3p) atoms specified according to magnetic substate combinations, 10.1088/0953-4075/25/22/018
  6. Urbain X, Blange J J, Dijkerman H A, Rudolph H, Heideman H G M, Internal energy distribution in Na2+ions formed through associative ionization as probed by photofragmentation, 10.1088/0953-4075/27/11/003
  7. Kortyna A., Reisner D., Unruh J., Hüwel L., Wavelength dependence of the absoluteNa2+(1Σu+2←1Σg+2) photodissociation cross section, 10.1103/physreva.50.1399
  8. Lucchese Robert R., Raseev Georges, McKoy Vincent, Studies of differential and total photoionization cross sections of molecular nitrogen, 10.1103/physreva.25.2572
  9. Lucchese Robert R., Takatsuka Kazuo, McKoy Vincent, Applications of the Schwinger variational principle to electron-molecule collisions and molecular photoionization, 10.1016/0370-1573(86)90147-x
  10. Kusch P., Hessel M. M., An analysis of the B 1Πu–X 1∑+g band system of Na2, 10.1063/1.436117
  11. M. W. Schmidt, QCPE Bull., 10, 52 (1990)
  12. Barrow R.F., Verges J., Effantin C., Hussein K., D'incan J., Long-range potentials for the X1∑g+ And (1)1Σg states and the dissociation energy of Na2, 10.1016/0009-2614(84)80192-x
  13. Lynch D. L., Dixit S. N., McKoy V., Shape resonances in the photoionization of cyanogen, 10.1063/1.449907
  14. Braunstein M., McKoy V., Shape resonances in the photoionization of N2O, 10.1063/1.453620
  15. Johnson B. R., New numerical methods applied to solving the one-dimensional eigenvalue problem, 10.1063/1.435384
  16. Rudolph H., Dixit S. N., McKoy V., Huo W. M., Ionic rotational branching ratios in resonant enhanced multiphoton ionization of NO via the A 2Σ+(3sσ) and D 2Σ+(3pσ) states, 10.1063/1.454191
  17. Carlson T. A., Krause M. O., Svensson W. A., Gerard P., Grimm F. A., Whitley T. A., Pullen B. P., Photoelectron dynamics of the cooper minimum in free molecules, 10.1007/bf01426235
  18. Park Hongkun, Zare Richard N., Evidence for a Cooper minimum in the photoionization dynamics of the NO D 2Σ+ state, 10.1016/0009-2614(94)87089-6
  19. Stephens J. A., McKoy V., Non-Franck-Condon Effects Induced by Orbital Evolution and Cooper Minima in Excited-State Photoionization of OH, 10.1103/physrevlett.62.889
  20. Stephens J A, Braunstein M, McKoy V, Rudolph H, Lee M T, Non-Franck-Condon effects induced by shape resonances and orbital evolution in resonance enhanced multiphoton ionization of small molecules, 10.1088/0031-8949/41/4/023
  21. Rudolph H., Dubs Richard L., McKoy V., Cooper minima and circular dichroism in photoelectron angular distributions, 10.1063/1.459377
  22. Rudolph H., Stephens J. A., McKoy V., Lee M.‐T., Vibrational state dependence of ionic rotational branching ratios in resonance enhanced multiphoton ionization of CH, 10.1063/1.457161
  23. Uzer T., Dalgarno A., Photodissociation of Na+2, 10.1016/0009-2614(79)80629-6
  24. Kirby-Docken K., Cerjan C.J., Dalgarno A., Oscillator strengths and photodissociation cross sections for Li2+ and Na2+, 10.1016/0009-2614(76)85059-2
  25. Rudolph H., Lynch D. L., Dixit S. N., McKoy V., Huo Winifred M., (2+1) resonant enhanced multiphoton ionization of H2 via the E,F 1Σ+g state, 10.1063/1.452174
  26. Cornaggia C., Giusti‐Suzor A., Jungen Ch., Photoionization of the EF excited state of H2: Calculation of vibrational branching ratios and photoelectron angular distributions, 10.1063/1.452947
  27. Napolitano Reginaldo, Weiner John, Williams Carl J., Julienne Paul S., Line Shapes of High Resolution Photoassociation Spectra of Optically Cooled Atoms, 10.1103/physrevlett.73.1352
  28. Cline R. A., Miller J. D., Heinzen D. J., Study ofRb2Long-Range States by High-Resolution Photoassociation Spectroscopy, 10.1103/physrevlett.73.632
  29. Ratliff L. P., Wagshul M. E., Lett P. D., Rolston S. L., Phillips W. D., Photoassociative spectroscopy of 1g, 0+u, and 0−g states of Na2, 10.1063/1.467638
Bibliographic reference Rudolph, H. ; Urbain, Xavier. Vibrational branching ratios for single-photon ionization of Na-2. In: Physical review. A, Atomic, molecular, and optical physics, Vol. 53, no. 6, p. 4111-4119 (1996)
Permanent URL http://hdl.handle.net/2078.1/47108