1. EII of plasma edge constituents, properties of Be x H y molecules S. Matejcik, P. Mach, J. Urban Comenius University Bratislava Slovakia

2. Bratislava

3. Overview - Appearance energies of C 2 D 6 - Cross section for EII to propane - BeH and BeH 2 – structure and energies - Structure and energetics of Be m H n clusters

4. Electron impact ionization cross sections (total, partial) ionization energies appearance energies kinetic energy release gas temperature dependencies products of the reactions

5. Experimental setup

6. Cross section measurements Absolute measurement of the pressure Relative flow technique Ar as a calibration gas

7. Atoms: Wannier theory:  w (E,AE,A,d) = 0 E<AE A(E-IE) d E>AE d=1.127 Threshold behaviour of the cross sections f(E,U) - EEDF Fitting function:

8. d=1.127±0.01 Threshold behaviour of the cross sections

9. CH 3 D AE (eV) 293 K CD 4 AE (eV) 293 K CH 4 AE (eV) 293 K CH 3 D + 12.75 ± 0.0312.89 ± 0.0312.65 ± 0.04CH 4 + CH 2 D + + H – CH 2 D + + H 13.66 ± 0.07 14.42 ± 0.05 - 14.54 ± 0.05 13.58 ± 0.1 14.34 ± 0.1 CH 3 + + H – CH 3 + + H Isotopic effect on AE Denifl et al. IJMS 248 (2005) 29

10. Present meV a) meV b) meV (CH 3 D) + /CH 3 D10050 (CH 2 D) + /CH 3 D80 (CH 3 ) + /CH 3 D200 (CHD) + /CH 3 D110 (CD 4 ) + /CD 4 190170160 (CD 3 ) + /CD 4 200130 (CD 2 ) + /CD 4 31090 a) F. P. Lossing, A. W. Tickner, W. A. Bryce, J. Chem. Phys. 19, 1254 (1951). b) V. H. Dibeler, M. Krauss, R. M. Reese, F. N. Harlee J. Chem. Phys. 42, 3791 (1965). Isotopic shift Denifl et al. IJMS 248 (2005) 29

11. EII of C 2 D 6 e + C 2 D 6 → C 2 D 6 + + 2e → C 2 D 5 + + D – + 2e → C 2 D 2 + + 2D 2 + e

12. EII to C 2 D 6

13. Izotopic effects in C 2 D 6 a E. Vaseková, M. Stano, S. Matejcik,, J.D. Skalný, P. Mach, T.D. Märk, J. Urban Int. J. of Mass Spect., 235 (2004) 155-162 e + C 2 D 6 →AE (in eV) PresentEthan a ( C 2 D 6 ) + 11.80 ± 0.0511.46 ± 0.06 ( C 2 D 5 ) + 11.78 ± 0.07 ?12.06± 0.03 ( C 2 D 4 ) + 12.09 ± 0.0811.9± 0.04 ( C 2 D 2 ) + 15.06± 0.215.02± 0.2

14. Grill et al. ZPhysD 25 (1993) 217

15. EII to C 3 H 8

16. Appearance energies C 3 H 8 Denifl CPL 402 (2005) 80

17. EII to C 3 H 8 cross sections Exp: N. Duric, I. Čadež, M. Kurepa, Int. J. Mass Spectrom. & Ion Processes, 108 (1991) R1-R10.

18. Total cross sections σ BEB (12 eV)σ Present (12 eV)σ Exp (12 eV) [10 -16 cm 2 ] 0.1190.210.35 Exp: N. Duric, I. Čadež, M. Kurepa, Int. J. Mass Spectrom. & Ion Processes, 108 (1991) R1-R10. BEB: W. Hwang, Y.-K. Kim and M.E. Rudd, J. Chem. Phys., 104 (1996) 2956

19. Cross sections at 700 K Not finnished yet Problems with contamination

20. EII to Be x H y Experimental problems Vaporisation only at T>1000°C Toxicity of Be

21. BeH dissoc. energy CCSDT-R12 1exc. energy 2 Σ – 2 Π, experiment 17086 cm -1, theory – 17116 cm -1

22. BeH bond lenght

23. BeH 2 basisBeH 2 Be-H [A] TAE a) [eV] DE Be+H2 [eV] CCSD(T)- R12 Be:19s14p8d6f4g H: 9s,6p,4d,3f 1.32606.4181.671 CCSD(T) Full aug-cc-pCvDZ1.33666.1081.585 aug-cc-pCvTZ1.32986.3211.614 aug-cc-pCvQZ1.32676.3911.657 aug-cc-pCv5Z1.32636.4061.664 B3LYP 6-311++G(3d,3p)1.32486.7411.965 aug-cc-pCv5Z1.32396.7481.964

24. BeH 2 bond lenght

25. Be n H clusters – MP2

26. Be n H 1

27. Be 3 H n Be 4 H n

29. Futher plans Propane cross section at high T C 2 D 6 – high T, cross sections Ionization energies of the Be compounds Appearance energies of the fragments Simulation of the Be surface Chemistry on the Be surface

30. Thank you for your attention