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ASTM E 262 : 2017 : R2024 : EDT 1

Current

Current

The latest, up-to-date edition.

Standard Test Method for Determining Thermal Neutron Reaction Rates and Thermal Neutron Fluence Rates by Radioactivation Techniques

Available format(s)

Hardcopy , PDF

Language(s)

English

Published date

14-05-2024

€61.92
Excluding VAT

Committee
E 10
DocumentType
Test Method
Pages
11
ProductNote
8.2.2.4 was editorially corrected in May 2024
PublisherName
American Society for Testing and Materials
Status
Current
Supersedes

1.1The purpose of this test method is to define a general procedure for determining an unknown thermal neutron fluence rate by neutron activation techniques. It is not practicable to describe completely a technique applicable to the large number of experimental situations that require the measurement of a thermal neutron fluence rate. Therefore, this method is presented so that the user may adapt to their particular situation the fundamental procedures of the following techniques.

1.1.1Radiometric counting technique using pure cobalt, pure gold, pure indium, cobalt-aluminum, alloy, gold-aluminum alloy, or indium-aluminum alloy.

1.1.2Standard comparison technique using pure gold, or gold-aluminum alloy, and

1.1.3Secondary standard comparison techniques using pure indium, indium-aluminum alloy, pure dysprosium, or dysprosium-aluminum alloy.

1.2The techniques presented are limited to measurements at room temperatures. However, special problems when making thermal neutron fluence rate measurements in high-temperature environments are discussed in 9.2. For those circumstances where the use of cadmium as a thermal shield is undesirable because of potential spectrum perturbations or of temperatures above the melting point of cadmium, the method described in Practice E481 can be used in some cases. Alternatively, gadolinium filters may be used instead of cadmium. For high-temperature applications in which aluminum alloys are unsuitable, other alloys such as cobalt-nickel or cobalt-vanadium have been used.

1.3This test method may be used to determine the equivalent 2200 m/s fluence rate. The accurate determination of the actual thermal neutron fluence rate requires knowledge of the neutron temperature, and determination of the neutron temperature is not within the scope of the standard.

1.4The techniques presented are suitable only for neutron fields having a significant thermal neutron component, in which moderating materials are present, and for which the average scattering cross section is large compared to the average absorption cross section in the thermal neutron energy range.

1.5Table 1 indicates the useful neutron fluence ranges for each detector material.

1.6This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM E 2006 : 2022 Standard Guide for Benchmark Testing of Light Water Reactor Calculations
ASTM E 1005 : 2021 Standard Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance
ASTM E 721 : 2022 Standard Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics
ASTM E 1854 : 2019 Standard Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts
ASTM E 261 : 2016 : R2021 Standard Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques
ASTM E 1297 : 2018 Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Niobium

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