Acta Physica Polonica. A, Vol. 95, nr 4 (1999), s. 632-636
Positron lifetimes measurements in polyethylene were performed. Sam- .
ples of the polyethylene were heated in the temperature range from 320 to
570 K. After cooling, the samples were used for the lifetime measurements
in air at room temperature. A conventional fast-slow coincidence lifetime
spectrometer was used for the measurements. Mean free volumes radii were
calculated from the lifetime data.