ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
Double differential cross sections of sodium in both the 3S ground state and the 3P electronically excited state scattered from SF6 and SiF4 have been measured at center of mass collision energies of 0.6 and 2.0 eV for SF6 and 1.0 eV for SiF4. For the experiments with Na(3P), a two frequency excitation scheme is applied, by which an excitation efficiency (determined by scattering experiments) of 31% is obtained. In the SF6 experiments, one finds a substantial transfer of the collision energy into the vibrational and rotational degrees of freedom of SF6. A transfer of electronic energy of Na(3P) into SF6 is not observed in nonreactive collisions. For the NaF formed in the reaction, an angular distribution originating from a long-lived complex, superimposed by a forward peak caused by a direct reaction mechanism is found. Especially the ground state measurements show an angular-dependent velocity distribution of the product. Compared to forward and backward scattering in sideways collisions, a lower velocity is found. From Na(3S) to Na(3P), the general characteristic does not change. The gain of reactivity with the excitation is decreasing with the collision energy. For the experiments with Na(3P) and SiF4, a quenching channel is found. The energy transferred to SiF4 is in good agreement with the prior distribution, calculated in a simplified RRHO model. The statistical behavior and the shape of the angular distribution of the intensity suggest the interpretation by the formation of a long-lived collisional complex. © 1998 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.477091
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