Technical Specification
ISO/TS 23878:2024
Nanotechnologies — Positron annihilation lifetime measurement for nanopore evaluation in materials
Reference number
ISO/TS 23878:2024
Edition 1
2024-08
Technical Specification
Preview
ISO/TS 23878:2024
77259
Indisponible en français
Publiée (Edition 1, 2024)

ISO/TS 23878:2024

ISO/TS 23878:2024
77259
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CHF 129
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Résumé

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.

Informations générales

  •  : Publiée
     : 2024-08
    : Norme internationale publiée [60.60]
  •  : 1
  • ISO/TC 229
    07.120 
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