ASTM E720-11
(Guide)Standard Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics
Standard Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics
SIGNIFICANCE AND USE
Because of the wide variety of materials being used in neutron-activation measurements, this guide is presented with the objective of bringing improved uniformity to the specific field of interest here: hardness testing of electronics primarily in critical assembly reactor environments.
Note 2—Some of the techniques discussed are useful for 14-MeV dosimetry. See Test Method E496 for activation detector materials suitable for 14-MeV neutron effects testing.
Note 3—The materials recommended in this guide are suitable for 252Cf or other weak source effects testing provided the fluence is sufficient to generate countable activities.
This guide is organized into two overlapping subjects; the criteria used for sensor selection, and the procedures used to ensure the proper determination of activities for determination of neutron spectra. See Terminology E170 and General Methods E181. Determination of neutron spectra with activation sensor data is discussed in Guides E721 and E944.
SCOPE
1.1 This guide covers the selection and use of neutron-activation detector materials to be employed in neutron spectra adjustment techniques used for radiation-hardness testing of electronic semiconductor devices. Sensors are described that have been used at many radiation hardness-testing facilities, and comments are offered in table footnotes concerning the appropriateness of each reaction as judged by its cross-section accuracy, ease of use as a sensor, and by past successful application. This guide also discusses the fluence-uniformity, neutron self-shielding, and fluence-depression corrections that need to be considered in choosing the sensor thickness, the sensor covers, and the sensor locations. These considerations are relevant for the determination of neutron spectra from assemblies such as TRIGA- and Godiva-type reactors and from Californium irradiators. This guide may also be applicable to other broad energy distribution sources up to 20 MeV.
Note 1—For definitions on terminology used in this guide, see Terminology E170.
1.2 This guide also covers the measurement of the gamma-ray or beta-ray emission rates from the activation foils and other sensors as well as the calculation of the absolute specific activities of these foils. The principal measurement technique is high-resolution gamma-ray spectrometry. The activities are used in the determination of the energy-fluence spectrum of the neutron source. See Guide E721.
1.3 Details of measurement and analysis are covered as follows:
1.3.1 Corrections involved in measuring the sensor activities include those for finite sensor size and thickness in the calibration of the gamma-ray detector, for pulse-height analyzer deadtime and pulse-pileup losses, and for background radioactivity.
1.3.2 The primary method for detector calibration that uses secondary standard gamma-ray emitting sources is considered in this guide and in General Methods E181. In addition, an alternative method in which the sensors are activated in the known spectrum of a benchmark neutron field is discussed in Guide E1018.
1.3.3 A data analysis method is presented which accounts for the following: detector efficiency; background subtraction; irradiation, waiting, and counting times; fission yields and gamma-ray branching ratios; and self-absorption of gamma rays and neutrons in the sensors.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
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Designation: E720 − 11
Standard Guide for
Selection and Use of Neutron Sensors for Determining
Neutron Spectra Employed in Radiation-Hardness Testing of
1
Electronics
This standard is issued under the fixed designation E720; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 1.3.2 The primary method for detector calibration that uses
secondary standard gamma-ray emitting sources is considered
1.1 This guide covers the selection and use of neutron-
in this guide and in General Methods E181. In addition, an
activationdetectormaterialstobeemployedinneutronspectra
alternative method in which the sensors are activated in the
adjustment techniques used for radiation-hardness testing of
known spectrum of a benchmark neutron field is discussed in
electronic semiconductor devices. Sensors are described that
Guide E1018.
have been used at many radiation hardness-testing facilities,
1.3.3 A data analysis method is presented which accounts
and comments are offered in table footnotes concerning the
for the following: detector efficiency; background subtraction;
appropriateness of each reaction as judged by its cross-section
irradiation, waiting, and counting times; fission yields and
accuracy, ease of use as a sensor, and by past successful
gamma-ray branching ratios; and self-absorption of gamma
application. This guide also discusses the fluence-uniformity,
rays and neutrons in the sensors.
neutron self-shielding, and fluence-depression corrections that
need to be considered in choosing the sensor thickness, the
1.4 The values stated in SI units are to be regarded as
sensor covers, and the sensor locations. These considerations standard. No other units of measurement are included in this
are relevant for the determination of neutron spectra from
standard.
assembliessuchasTRIGA-andGodiva-typereactorsandfrom
1.5 This standard does not purport to address all of the
Californium irradiators. This guide may also be applicable to
safety concerns, if any, associated with its use. It is the
other broad energy distribution sources up to 20 MeV.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
NOTE 1—For definitions on terminology used in this guide, see
Terminology E170.
bility of regulatory limitations prior to use.
1.2 This guide also covers the measurement of the gamma-
2. Referenced Documents
ray or beta-ray emission rates from the activation foils and
other sensors as well as the calculation of the absolute specific
2.1 General considerations of neutron-activation detectors
activities of these foils. The principal measurement technique
discussed in Practice E261, Test Method E262, and Guides
is high-resolution gamma-ray spectrometry. The activities are
E721 and E844 are applicable to this guide. Background
usedinthedeterminationoftheenergy-fluencespectrumofthe
informationforapplyingthisguidearegivenintheseandother
neutron source. See Guide E721.
relevant standards as follows:
2
1.3 Details of measurement and analysis are covered as
2.2 ASTM Standards:
follows:
E170Terminology Relating to Radiation Measurements and
1.3.1 Corrections involved in measuring the sensor activi-
Dosimetry
ties include those for finite sensor size and thickness in the
E181Test Methods for Detector Calibration andAnalysis of
calibration of the gamma-ray detector, for pulse-height ana-
Radionuclides
lyzer deadtime and pulse-pileup losses, and for background
E261Practice for Determining Neutron Fluence, Fluence
radioactivity.
Rate, and Spectra by Radioactivation Techniques
1
This guide is under the jurisdiction of ASTM Committee E10 on Nuclear
Technology and Applicationsand is the direct responsibility of Subcommittee
2
E10.07 on Radiation Dosimetry for Radiation Effects on Materials and Devices. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJune1,2011.PublishedJuly2011.Originallyapproved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 1980. Last previous edition approved in 2008 as E720–08. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
E0720-11. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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E720 − 11
E262Test Method for Determining Thermal Neutron Reac- the ENDF/B-VI (1, 2),3 and IRDF-90 (3) cross-sections.These
tion
...
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:E720–08 Designation:E720–11
Standard Guide for
Selection and Use of Neutron Sensors for Determining
Neutron Spectra Employed in Radiation-Hardness Testing of
1
Electronics
This standard is issued under the fixed designation E720; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This guide covers the selection and use of neutron-activation detector materials to be employed in neutron spectra
adjustment techniques used for radiation-hardness testing of electronic semiconductor devices. Sensors are described that have
beenusedatmanyradiationhardness-testingfacilities,andcommentsareofferedintablefootnotesconcerningtheappropriateness
ofeachreactionasjudgedbyitscross-sectionaccuracy,easeofuseasasensor,andbypastsuccessfulapplication.Thisguidealso
discussesthefluence-uniformity,neutronself-shielding,andfluence-depressioncorrectionsthatneedtobeconsideredinchoosing
thesensorthickness,thesensorcovers,andthesensorlocations.Theseconsiderationsarerelevantforthedeterminationofneutron
spectra from assemblies such as TRIGA- and Godiva-type reactors and from Californium irradiators. This guide may also be
applicable to other broad energy distribution sources up to 20 MeV.
NOTE 1—For definitions on terminology used in this guide, see Terminology E170.
1.2 This guide also covers the measurement of the gamma-ray or beta-ray emission rates from the activation foils and other
sensors as well as the calculation of the absolute specific activities of these foils. The principal measurement technique is
high-resolutiongamma-rayspectrometry.Theactivitiesareusedinthedeterminationoftheenergy-fluencespectrumoftheneutron
source. See Guide E721.
1.3 Details of measurement and analysis are covered as follows:
1.3.1 Corrections involved in measuring the sensor activities include those for finite sensor size and thickness in the calibration
of the gamma-ray detector, for pulse-height analyzer deadtime and pulse-pileup losses, and for background radioactivity.
1.3.2 Theprimarymethodfordetectorcalibrationthatusessecondarystandardgamma-rayemittingsourcesisconsideredinthis
guide and in General Methods E181. In addition, an alternative method in which the sensors are activated in the known spectrum
of a benchmark neutron field is discussed in Guide E1018.
1.3.3 A data analysis method is presented which accounts for the following: detector efficiency; background subtraction;
irradiation, waiting, and counting times; fission yields and gamma-ray branching ratios; and self-absorption of gamma rays and
neutrons in the sensors.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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
2.1 Generalconsiderationsofneutron-activationdetectorsdiscussedinPracticeE261,TestMethodE262,andGuidesE721and
E844 are applicable to this guide. Background information for applying this guide are given in these and other relevant standards
as follows:
2
2.2 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and Dosimetry
E181 Test Methods for Detector Calibration and Analysis of Radionuclides
1
This guide is under the jurisdiction of ASTM Committee E10 on Nuclear Technology and Applications and is the direct responsibility of Subcommittee E10.07 on
Radiation Dosimetry for Radiation Effects on Materials and Devices.
´1
CurrenteditionapprovedJuly1,2008.PublishedJuly2008.Originallyapprovedin1980.Lastpreviouseditionapprovedin2004asE720–04 .DOI:10.1520/E0720-08.
Current edition approved June 1, 2011. Published July 2011. Originally approved in 1980. Last previous edition approved in 2008 as E720–08. DOI: 10.1520/E0720-11.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book ofASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, W
...
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