Full Description

This document describes a method for performing positron annihilation lifetime measurements using a 22Na positron source that decays with β+ emission. The β+ (positron) lifetime is determined from a measurement of the lifetime of the ortho-positronium which ranges from 1 ns to 10 ns (ascribed to a pore size from approximately 0,3 nm to 1,3 nm in diameter), as observed for polymeric materials in which the positronium atoms mostly annihilate via a two-gamma annihilation process.

This document is not applicable to thin surface layers (that are less than several micrometers).

This document does not apply to measuring:
— non-positronium forming materials;
— positronium-forming materials that induce a spin conversion reaction;
— positronium-forming materials that contain chemicals influencing the annihilation process of ortho-positronium by chemical reactions;
— positronium-forming materials that contain mesoporous silica gels with a large contribution from the three-gamma annihilation process.

Product Details

Published:

08/31/2024

ISBN(s):

9780539159509

Number of Pages:

30

File Size:

1 file , 2.3 MB

Note:

This product is restricted and cannot be purchased in the following countries Ukraine, Russia, Belarus