ASTM E266-11

Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Aluminum

SIGNIFICANCE AND USE
Refer to Guide E844 for the selection, irradiation, and quality control of neutron dosimeters.
Refer to Practice E261 for a general discussion of the determination of fast-neutron fluence rate with threshold detectors.
Pure aluminum in the form of foil or wire is readily available and easily handled.  27Al has an abundance of 100 % (1) .
24Na has a half-life of 14.9574 h (2) and emits gamma rays with energies of 1.368626 and 2.754007 MeV (2).
Fig. 1 shows a plot of cross section versus neutron energy for the fast-neutron reaction  27Al(n,α)24Na (3) along with a comparison to the current experimental database (4). This figure is for illustrative purposes only to indicate the range of response of the  27Al(n,α) reaction. Refer to Guide E1018 for descriptions of recommended tabulated dosimetry cross sections.
Two competing activities,  28Al and  27Mg, are formed in the reactions  27Al(n,γ) 28Al and  27Al(n,p) 27Mg, respectively, but these can be eliminated by waiting 2 h before counting.
SCOPE
1.1 This test method covers procedures measuring reaction rates by the activation reaction  27Al(n,α)24Na.
1.2 This activation reaction is useful for measuring neutrons with energies above approximately 6.5 MeV and for irradiation times up to about 2 days (for longer irradiations, see Practice E261).
1.3 With suitable techniques, fission-neutron fluence rates above 106 cm−2·s−1 can be determined.
1.4 Detailed procedures for other fast neutron detectors are referenced in Practice E261.
1.5 This 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-May-2011
• ICS: 17.240 - Radiation measurements
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.05 - Nuclear Radiation Metrology

Relations

• Replaces: ASTM E266-07 - Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Aluminum
• Effective Date: 01-Jun-2011
• Referred By: ASTM E720-23 - Standard Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics
• Effective Date: 01-Jun-2011
• Referred By: ASTM E798-16 - Standard Practice for Conducting Irradiations at Accelerator-Based Neutron Sources
• Effective Date: 01-Jun-2011
• Referred By: ASTM E2005-21 - Standard Guide for Benchmark Testing of Reactor Dosimetry in Standard and Reference Neutron Fields
• Effective Date: 01-Jun-2011
• Referred By: ASTM E944-19 - Standard Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance
• Effective Date: 01-Jun-2011
• Referred By: ASTM E1005-21 - Standard Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance
• Effective Date: 01-Jun-2011
• Referred By: ASTM E721-22 - Standard Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics
• Effective Date: 01-Jun-2011
• Referred By: ASTM E261-16(2021) - Standard Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques
• Effective Date: 01-Jun-2011

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E266 − 11
Standard Test Method for
Measuring Fast-Neutron Reaction Rates by Radioactivation
1
of Aluminum
This standard is issued under the fixed designation E266; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E1018Guide for Application of ASTM Evaluated Cross
Section Data File, Matrix E706 (IIB)
1.1 This test method covers procedures measuring reaction
27 24
rates by the activation reaction Al(n,α) Na.
3. Terminology
1.2 Thisactivationreactionisusefulformeasuringneutrons
3.1 Definitions:
withenergiesaboveapproximately6.5MeVandforirradiation
3.1.1 Refer to Terminology E170.
times up to about 2 days (for longer irradiations, see Practice
E261).
4. Summary of Test Method
1.3 With suitable techniques, fission-neutron fluence rates
4.1 High-purity aluminum is irradiated in a neutron field,
6 −2 −1
24 27 24
above 10 cm ·s can be determined.
thereby producing radioactive Na from the Al(n,α) Na
activation reaction.
1.4 Detailed procedures for other fast neutron detectors are
referenced in Practice E261.
4.2 The gamma rays emitted by the radioactive decay of
24
1.5 This standard does not purport to address all of the Na are counted (see Test Methods E181) and the reaction
rate, as defined by Practice E261, is calculated from the decay
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- rate and irradiation conditions.
priate safety and health practices and determine the applica-
4.3 The neutron fluence rate above about 6.5 MeVcan then
bility of regulatory limitations prior to use.
be calculated from the spectral-weighted neutron activation
cross section as defined by Practice E261.
2. Referenced Documents
2
2.1 ASTM Standards:
5. Significance and Use
E170Terminology Relating to Radiation Measurements and
5.1 Refer to Guide E844 for the selection, irradiation, and
Dosimetry
quality control of neutron dosimeters.
E181Test Methods for Detector Calibration andAnalysis of
5.2 Refer to Practice E261 for a general discussion of the
Radionuclides
determination of fast-neutron fluence rate with threshold de-
E261Practice for Determining Neutron Fluence, Fluence
tectors.
Rate, and Spectra by Radioactivation Techniques
E844Guide for Sensor Set Design and Irradiation for
5.3 Pure aluminum in the form of foil or wire is readily
27
Reactor Surveillance, E 706 (IIC)
available and easily handled. Al has an abundance of 100 %
3
E944Guide for Application of Neutron Spectrum Adjust-
(1) .
ment Methods in Reactor Surveillance, E 706 (IIA)
24
5.4 Na has a half-life of 14.9574 h (2) and emits gamma
E1005Test Method for Application and Analysis of Radio-
rays with energies of 1.368626 and 2.754007 MeV(2).
metric Monitors for Reactor Vessel Surveillance, E 706
5.5 Fig. 1 shows a plot of cross section versus neutron
(IIIA)
27 24
energy for the fast-neutron reaction Al(n,α) Na (3) along
with a comparison to the current experimental database (4).
1
ThistestmethodisunderthejurisdictionofASTMCommitteeE10onNuclear
Thisfigureisforillustrativepurposesonlytoindicatetherange
Technology and Applicationsand is the direct responsibility of Subcommittee
27
E10.05 on Nuclear Radiation Metrology.
ofresponseofthe Al(n,α)reaction.RefertoGuideE1018for
Current edition approved June 1, 2011. Published June 2011. Originally
descriptions of recommended tabulated dosimetry cross sec-
approved in 1965. Last previous edition approved in 2007 as E266–07. DOI:
tions.
10.1520/E0266-11.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on The boldface numbers in parentheses refer to a list of References at the end of
the ASTM website. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E266 − 11
Section 9, and adjust sample size and irradiation time so that
24
the Na may be accurately counted. A trial irradiation is
recommended.
8.2 Determine a suitable irradiation time (see 8.1).
24 24
Since Na has a 14.9574 h half-life, the Na activity will
approach equilibrium after a day of irradiation.
8.3 Weigh the sample.
8.4 Irradiate the sample for the predetermined time period.
Record the power level and any changes in power during the
irradiation,thetimeatthebeginningandendoftheirradiation,
and the relative position of the monitors in the irradiation
facility.
8.5 After irr
...

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:E266–07 Designation:E266–11
Standard Test Method for
Measuring Fast-Neutron Reaction Rates by Radioactivation
1
of Aluminum
This standard is issued under the fixed designation E266; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
27 24
1.1 This test method covers procedures measuring reaction rates by the activation reaction Al(n,a) Na.
1.2 This activation reaction is useful for measuring neutrons with energies above approximately 6.5 MeV and for irradiation
times up to about 2 days (for longer irradiations, see Practice E261).
−2
6 cm −1
1.3 With suitable techniques, fission-neutron fluence rates above 10 ·cm ·s can be determined.
1.4 Detailed procedures for other fast neutron detectors are referenced in Practice E261.
1.5 This 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and Dosimetry
E181 Test Methods for Detector Calibration and Analysis of Radionuclides
E261 Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques
E844 Guide for Sensor Set Design and Irradiation for Reactor Surveillance, E 706 (IIC)
E944 Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance, E 706 (IIA)
E1005 Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance, E 706 (IIIA)
E1018 Guide for Application of ASTM Evaluated Cross Section Data File, Matrix E706 (IIB)
3. Terminology
3.1 Definitions:
3.1.1 Refer to Terminology E170.
4. Summary of Test Method
24 27 24
4.1 High-purityaluminumisirradiatedinaneutronfield,therebyproducingradioactive Nafromthe Al(n,a) Naactivation
reaction.
24
4.2 The gamma rays emitted by the radioactive decay of Na are counted (see Test Methods E181) and the reaction rate, as
defined by Practice E261, is calculated from the decay rate and irradiation conditions.
4.3 The neutron fluence rate above about 6.5 MeV can then be calculated from the spectral-weighted neutron activation cross
section as defined by Practice E261.
5. Significance and Use
5.1 Refer to Guide E844 for the selection, irradiation, and quality control of neutron dosimeters.
5.2 Refer to Practice E261 for a general discussion of the determination of fast-neutron fluence rate with threshold detectors.
5.3 Pure aluminum in the form of foil or wire is readily available and easily handled.
24 27 3
5.4 NaAlhasahalf-lifeanabundanceof14.951h100% (1) andemitsgammarayswithenergiesof1.368.633and2.754028
MeV .
1
This test method is under the jurisdiction of ASTM Committee E10 on Nuclear Technology and Applications and is the direct responsibility of Subcommittee E10.05
on Nuclear Radiation Metrology.
Current edition approved June 1, 2007.2011. Published June 2007. Originally approved in 1965. Last previous edition approved in 20022007 as E266–027. DOI:
10.1520/E0266-07.10.1520/E0266-11.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail] Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The boldface numbers in parentheses refer to a list of References at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E266–11
24
5.4 Na has a half-life of 14.9574 h (2) and emits gamma rays with energies of 1.368626 and 2.754007 MeV (2).
27 24
5.5 Fig. 1 shows a plot of cross section versus neutron energy for the fast-neutron reaction Al(n,a) Na from the IRDF2002
dosimetry cross section library Na (3) along with a comparison to the current experimental database (4). This figure is for
27
illustrative purposes only to indicate the range of response of the Al(n,a) reaction. Refer to Guide E1018 for descriptions
of recommended tabulated dosimetry cross sections.
28 27 27 28 27 27
5.6 Two competing activities, Al and Mg, are formed in the reactions Al(n,g) Al and Al(n,p) Mg,
...