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Selected Document Category:	Published Document
Source:	International Organization for Standardization
Anticipated Publication Year:	2023
Publication Year:	2024
Acronym:	ISO
Identifier:	TS 23878
Document Title:	Nanotechnologies -- Positron annihilation lifetime measurement for nanopore evaluation in materials
url:	https://webstore.ansi.org/standards/iso/isots238782024
Scope:	This document describes a method for performing positron annihilation lifetime measurements with a 22Na positron source with beta-plus decay to analyze the lifetime of positrons as a mean lifetime of the ortho-positronium from 1 ns to 10 ns (ascribed to the pore size, approximately, from 0.3 nm to 1.3 nm in diameter), observed for polymeric materials in which the positronium atoms mostly annihilate via a two-gamma annihilation process. This document is not applicable for measuring non-positronium forming metals, positronium-forming materials that induce a spin conversion reaction or contain chemicals influencing the annihilation process of ortho-positronium by chemical reactions, as well as mesoporous silica gels with a large contribution from the three-gamma annihilation process.
Keywords:
Type of Document:	a. Standard
Issues Areas:	Measurement and Characterizations
Primary Category:
Additional Categories
Goal or Need:
Intended Stakeholders:
Is it Being Implemented:
Submitter's Name:	Heather Benko
Submitter's e-mail:	[email protected]
Submitter's Company:	ANSI
Additional Comments:
Contact for Additional Info:

Selected Document Category:	Published Document
Source:	International Organization for Standardization
Anticipated Publication Year:	2023
Publication Year:	2024
Acronym:	ISO
Identifier:	TS 23878
Document Title:	Nanotechnologies -- Positron annihilation lifetime measurement for nanopore evaluation in materials
url:	https://webstore.ansi.org/standards/iso/isots238782024
Scope:	This document describes a method for performing positron annihilation lifetime measurements with a 22Na positron source with beta-plus decay to analyze the lifetime of positrons as a mean lifetime of the ortho-positronium from 1 ns to 10 ns (ascribed to the pore size, approximately, from 0.3 nm to 1.3 nm in diameter), observed for polymeric materials in which the positronium atoms mostly annihilate via a two-gamma annihilation process. This document is not applicable for measuring non-positronium forming metals, positronium-forming materials that induce a spin conversion reaction or contain chemicals influencing the annihilation process of ortho-positronium by chemical reactions, as well as mesoporous silica gels with a large contribution from the three-gamma annihilation process.
Keywords:
Type of Document:	a. Standard
Issues Areas:	Measurement and Characterizations
Primary Category:
Additional Categories
Goal or Need:
Intended Stakeholders:
Is it Being Implemented:
Submitter's Name:	Heather Benko
Submitter's e-mail:	[email protected]
Submitter's Company:	ANSI
Additional Comments:
Contact for Additional Info:

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