Slow Positron Studies in Polymers

Abstract:

Article Preview

The diffusion trapping model has been applied to slow positron annihilation in He+ irradiated polystyrene and polystyrene – polystyrene bilayers. The S-parameter and the positron lifetime have been calculated as a function of the incident positron energy. The effect of the fluence upon the nature of the S-parameter curve has been discussed. It has been found that a change in fluence affects positronium formation. The transition rate for surface to positronium formation has been found to be dependent upon the fluence and the atomic number of the irradiated ion. The lifetime results show that, at low energy, the o-Ps annihilates mainly at the polymeric surface. The free volume hole concentration is found to decrease at low energy, and becomes constant at higher energies.

Info:

Periodical:

Edited by:

David J. Fisher

Pages:

85-92

DOI:

10.4028/www.scientific.net/DDF.307.85

Citation:

S.B. Shrivastava et al., "Slow Positron Studies in Polymers", Defect and Diffusion Forum, Vol. 307, pp. 85-92, 2010

Online since:

December 2010

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.