Reply to the Comment on "Rotational Alignment in Supersonic Seeded Beams of Molecular Oxygen" (by Charles D. Pibel, Joshua B. Halpern)

Journal of Physical Chemistry A

Volumn 103, Issue 22, 1999, Pages 4424-4426

  Aquilanti, Vincenzo ^a   Ascenzi, Daniela ^a   Cappelletti, David ^a,b   Pirani, Fernando ^a  

^a Dipartimento di Chimica dell'UniVersitá   (Italy)

^b UNIVERSITY OF PERUGIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 78649709585     PISSN: 10895639     EISSN: 15205215     Source Type: Journal    
DOI: 10.1021/jp9838846     Document Type: Note

References (26)

1. Aquilanti, V.; Ascenzi, D.; Cappelletti, D.; Pirani, F. Nature 1994, 371, 399.
2. Aquilanti, V.; Ascenzi, D.; Cappelletti, D.; Pirani, F. J. Phys. Chem. 1995, 99, 13620.
3. Aquilanti, V.; Ascenzi, D.; Cappelletti, D.; Franceschini, S.; Pirani, F. Phys. ReV. Lett. 1995, 74, 2929.
4. Anthony, E. B.; Schade, W.; Bastian, M. J.; Bierbaum, V. M.; Leone, S. R. J. Chem. Phys. 1997, 106, 5413.
5. Harich, S.; Wodtke, A. M. J. Chem. Phys. 1997, 107, 5983.
6. Pibel, C. D.; Halpern, J. B. J. Phys. Chem. A 1999, 103, 4421.
7. Note that values of the degree of alignment reported in Table 2 of ref 2 must be considered as the average of several measurements performed under slightly different experimental conditions, while the weights W(J,mJ) reported in Table 1 of the same paper refer to one sample set of data and are not sufficient to fully reconstruct results in Table 2.
8. Aquilanti, V.; Ascenzi, D.; Cappelletti, D.; De Castro, M.; Pirani, F. J. Chem. Phys. 1998, 109, 3839.
9. An example of the important role of this coupling is given in: Happer, W.; Miron, E.; Schaefer, S.; Schreiber, D.; van Wijngaarden, W. A.; Zeng, X. Phys. ReV. A 1984, 29, 3092.
10. The recoupling of polarized K with S to give J, which occurs also between successive collisions in the expansion, would lead to a natural depolarization effect in the case of unpolarized spin (see: Altkorn, R.; Zare, R. N.; Greene, C. H. Mol. Phys. 1985, 55, 1). In such conditions the maximum alignment observable for K ) 1 should be even lower with respect to that obtained according to PH.
11. Aquilanti, V.; Ascenzi, D.; Cappelletti, D.; Fedeli, R.; Pirani, F. J. Phys. Chem. A 1997, 101, 7648. In this paper anisotropy effects for the N2-Xe system on the value of the cross section and on the position of "glory" extrema have been measured. The observed effects are of the same magnitude as in a pioneering work on the scattering of NO, state selected by a hexapolar field and oriented by means of a magnetic field
12. see: Thuis, H. H. W.; Stolte, S.; Reuss, J. Chem. Phys. 1979, 43, 351.
13. Sinha, M. P.; Caldwell, C. D.; Zare, R. N. J. Chem. Phys. 1975, 61, 491.
14. Visser, A. G.; Bekooy, J. P.; van der Meij, L. K.; de Vreugd, C.; Korving, J. Chem. Phys. 1977, 20, 391.
15. Hefter, U.; Ziegler, G.; Mattheus, A.; Fischer, A.; Bergmann, K. J. Chem. Phys. 1986, 85, 286.
16. Pullman, D. P.; Friedrich, B.; Herschbach, D. R. J. Chem. Phys. 1990, 93, 322.
17. Friedrich, B.; Pullman, D. P.; Herschbach, D. R. J. Phys. Chem. 1991, 95, 8118.
18. Weida, M. J.; Nesbitt, D. J. J. Chem. Phys. 1994, 100, 6372.
19. Saleh, H. J.; McCaffery, A. J. J. Chem. Soc., Faraday Trans. 1993, 89, 3217.
20. Pullman, D. P.; Friedrich, B.; Herschbach, D. R. J. Phys. Chem. 1995, 99, 7407.
21. Simple models based on classical mechanics cannot be exhaustive in the comprehensive of a phenomenon where the rotational relaxation plays such a dominant role.
22. Beneventi, L.; Casavecchia, P.; Volpi, G. G. J. Chem. Phys. 1986, 85, 7011.
23. In ref 8 close-coupling quantum-mechanical calculations have been reported supporting the experimentally observed effects for O2-Kr and O2- Xe systems. The same code is used here for the O2-He system. See: Aquilanti, V.; Ascenzi, D.; de Castro Vítores, M.; Pirani, F.; Cappelletti, D. J. Chem. Phys., in press.
24. The O2 molecules in the beam source exhibit a broad distribution of rotational levels (significantly populated up to K ) 21). The level K ) 5 is among the most populated ones.
25. See for instance: Kuebler, N. A.; Robin, M. B.; Yang, J. J.; Gedanken, A.; Herrick, D. R. Phys. ReV. A 1988, 38, 737.
26. Matsumoto, T.; Kuwata, K. Chem. Phys. Lett. 1990, 171, 314.