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Progress report: Calculations on BeH +

Progress report: Calculations on BeH +. Åsa Larson, Stockholm University Johanna Roos, Stockholm University Ann Orel, UC Davis Mats Larsson, Stockholm University. Motivation. Beryllium used for the first wall and limiter BeH + formed in the plasma

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Progress report: Calculations on BeH +

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  1. Progress report:Calculations on BeH+ Åsa Larson, Stockholm University Johanna Roos, Stockholm University Ann Orel, UC Davis Mats Larsson, Stockholm University

  2. Motivation • Beryllium used for the first wall and limiter • BeH+ formed in the plasma • How fast does it recombine with electrons? • Problem: toxicity of Be; experiments not the preferred choice

  3. What has been done • Theoretical work on BexHy was reported by Stefan Matejcik at the CRP-meeting in June 2007 • High resolution spectroscopy work on BeH published in 2006 (Le Roy et al. J.Mol.Spec.) • High resolution work on BeH+ published by Coxon & Colin, J. Mol. Spec. 1997 • Theoretical calculations by several groups

  4. JCP 2008

  5. Dissociative recombination Be + H BeH+ + e

  6. Results for diatomic hydrides

  7. MRCI calculations on the excited states of the ion:

  8. MRCI calculations on the excited states of BeH (2A1 symmetry)

  9. MRCI calculations on the excited states of BeH (2A2 symmetry)

  10. MRCI calculations on the excited states of BeH (2B1 symmetry)

  11. Electron scattering calculations Using the Complex Kohn variational method, the resonant states of BeH are calculated. Trial wave function: Insert into a variational functional for the T-matrix ci, dμ, T Eigenphase sum of the T-matrix: Eres(R), Γres(R) Target wave function MRCI Correlation and polarization

  12. Eigenphase sum: 2A1 symmetry (2Σ+, 2∆) R = 2.5 a0

  13. Combine resonant potentials obtained with the electron scattering calculation with the electronically bound states obtained with structure calculation. Quasidiabatization 2Σ+ symmetry:

  14. 2Π symmetry

  15. 2∆ symmetry

  16. The driven time-independent SE The resonant state potential PRA 71, 052714 (2005) The driving term or ”entry amplitude” Partial cross section Total cross section Molecular Dynamics with a time-independent nonlocal model

  17. Cross sections Partial cross section for Δ states Partial cross section for Π states Partial cross section for Σ states Total cross section

  18. Concluding remarks • The calculations will be finalized with nonadiabatic couplings included • CRYRING will be used for a few experiments during 2009, and then in 2010 moved to Darmstadt (FAIR) • A new double electrostatic storge ring, Desiree, will be commissioned in Stockholm during 2009

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