| NUKLEONIKA 2010, 55(1):9-12
POSITRON LIFETIME CALCULATIONS FOR SOME ELEMENTS
ON THE BASE OF THE GGA-PHNC APPROXIMATION
Edward Boroński
Institute of Physics, Opole University, 48 Oleska Str., 45-052 Opole, Poland
In studies of several interesting materials by positron annihilation technique the theoretical values of positron lifetimes in bulk and defected elements are useful. These lifetimes are often calculated within the GGA approximation. In this approximation the results of Arponen and Pajanne calculations for the positron in an electron gas are used. It is known, however, that when using the LDA approximation for the calculations of positron lifetime in real metals, Arponen and Pajanne values yield worse agreement with experimental data than the results obtained on the basis of PHNC formalism. Therefore, in this paper the appropriate PHNC formulas are incorporated into the GGA approximation and the calculations have been performed for some metals: bulk as well as containing monovacancies. The comparison of the lifetimes found in this way to the ones based on the previous method is promising for the applicability of the new algorithm.
Close X |