ASTM E666-21
(Practice)Standard Practice for Calculating Absorbed Dose From Gamma or X Radiation
Standard Practice for Calculating Absorbed Dose From Gamma or X Radiation
SIGNIFICANCE AND USE
4.1 The absorbed dose is a more meaningful parameter than exposure for use in relating the effects of radiation on materials. It expresses the energy absorbed by the irradiated material per unit mass, whereas exposure is related to the amount of charge produced in air per unit mass. Absorbed dose, as referred to here, implies that the measurement is made under conditions of charged particle (electron) equilibrium (see Appendix X1). In practice, such conditions are not rigorously achievable but, under some circumstances, can be approximated closely.
4.2 Different materials, when exposed to the same radiation field, absorb different amounts of energy. Using the techniques of this standard, charged particle equilibrium must exist in order to relate the absorbed dose in one material to the absorbed dose in another. Also, if the radiation is attenuated by a significant thickness of an absorber, the energy spectrum of the radiation will be changed, and it will be necessary to correct for this.
Note 1: For comprehensive discussions of various dosimetry methods applicable to the radiation types and energies and absorbed dose rate ranges discussed in this method, see ICRU Reports 34 and 80.
SCOPE
1.1 This practice presents a technique for calculating the absorbed dose in a material from knowledge of the radiation field, the composition of the material, (1-5)2,3 and a related measurement. The procedure is applicable for X and gamma radiation provided the energy of the photons fall within the range from 0.01 to 20 MeV.
1.2 A method is given for calculating the absorbed dose in a material from the knowledge of the absorbed dose in another material exposed to the same radiation field. The procedure is restricted to homogeneous materials composed of the elements for which absorption coefficients have been tabulated. All 92 natural elements are tabulated in (2). It also requires some knowledge of the energy spectrum of the radiation field produced by the source under consideration. Generally, the accuracy of this method is limited by the accuracy to which the energy spectrum of the radiation field is known.
1.3 The results of this practice are only valid if charged particle equilibrium exists in the material and at the depth of interest. Thus, this practice is not applicable for determining absorbed dose in the immediate vicinity of boundaries between materials of widely differing atomic numbers. For more information on this topic, see Practice E1249.
1.4 Energy transport computer codes4 exist that are formulated to calculate absorbed dose in materials more precisely than this method. To use these codes, more effort, time, and expense are required. If the situation warrants, such calculations should be used rather than the method described here.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This 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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This 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.
Designation: E666 − 21
Standard Practice for
1
Calculating Absorbed Dose From Gamma or X Radiation
This standard is issued under the fixed designation E666; 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 than this method. To use these codes, more effort, time, and
expense are required. If the situation warrants, such calcula-
1.1 This practice presents a technique for calculating the
tions should be used rather than the method described here.
absorbed dose in a material from knowledge of the radiation
2,3
1.5 This standard does not purport to address all of the
field, the composition of the material, (1-5) and a related
safety concerns, if any, associated with its use. It is the
measurement. The procedure is applicable for X and gamma
responsibility of the user of this standard to establish appro-
radiation provided the energy of the photons fall within the
priate safety, health, and environmental practices and deter-
range from 0.01 to 20 MeV.
mine the applicability of regulatory limitations prior to use.
1.2 A method is given for calculating the absorbed dose in
1.6 This international standard was developed in accor-
a material from the knowledge of the absorbed dose in another
dance with internationally recognized principles on standard-
material exposed to the same radiation field. The procedure is
ization established in the Decision on Principles for the
restrictedtohomogeneousmaterialscomposedoftheelements
Development of International Standards, Guides and Recom-
for which absorption coefficients have been tabulated. All 92
mendations issued by the World Trade Organization Technical
natural elements are tabulated in (2). It also requires some
Barriers to Trade (TBT) Committee.
knowledge of the energy spectrum of the radiation field
produced by the source under consideration. Generally, the
2. Referenced Documents
accuracyofthismethodislimitedbytheaccuracytowhichthe
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2.1 ASTM Standards:
energy spectrum of the radiation field is known.
E170Terminology Relating to Radiation Measurements and
1.3 The results of this practice are only valid if charged
Dosimetry
particle equilibrium exists in the material and at the depth of
E668Practice for Application of Thermoluminescence-
interest. Thus, this practice is not applicable for determining
Dosimetry (TLD) Systems for Determining Absorbed
absorbeddoseintheimmediatevicinityofboundariesbetween
DoseinRadiation-HardnessTestingofElectronicDevices
materials of widely differing atomic numbers. For more infor-
E1249Practice for Minimizing Dosimetry Errors in Radia-
mation on this topic, see Practice E1249.
tionHardnessTestingofSiliconElectronicDevicesUsing
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1.4 Energy transport computer codes exist that are formu- Co-60 Sources
lated to calculate absorbed dose in materials more precisely
2.2 International Commission on Radiation Units and Mea-
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surements (ICRU) Reports:
ICRUReport18SpecificationofHighActivityGamma-Ray
1
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
Sources
Technology and Applications and is the direct responsibility of Subcommittee
ICRUReport21RadiationDosimetry:ElectronswithInitial
E10.07 on Radiation Dosimetry for Radiation Effects on Materials and Devices.
Current edition approved Feb. 1, 2021. Published March 2021. Originally
Energies Between 1 and 50 MeV
approved in 1978. Last previous edition approved in 2014 as E666-14. DOI:
ICRU Report 34The Dosimetry of Pulsed Radiation
10.1520/E0666-21.
2
ICRUReport51RadiationQuantitiesandUnitsinRadiation
The boldface numbers in parentheses refer to the list of references appended to
this practice.
Protection Dosimetry
3
See also ICRU Report 80. For calculation of absorbed dose in dosimetry
ICRU Report 60Radiation Fundamental Quantities and
systemsandmaterialsusedinradiationprocessing,massattenuationcoefficientsand
Units for Ionizing Radiation
mass-energy absorption coefficients for key elements, compounds and materials
used in radiation processing dosimetry over the photon range from 100 keV to 20
MeV are given in Appendix 1 of that report.
4 5
Information on and packages of computer codes can be obtained from The For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Radiation Safety Information Computational Center, Oak Ridge National contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM 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: E666 − 14 E666 − 21
Standard Practice for
1
Calculating Absorbed Dose From Gamma or X Radiation
This standard is issued under the fixed designation E666; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number 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
1.1 This practice presents a technique for calculating the absorbed dose in a material from knowledge of the radiation field, the
2,3
composition of the material, (1-5) and a related measurement. The procedure is applicable for X and gamma radiation provided
the energy of the photons fall within the range from 0.01 to 20 MeV.
1.2 A method is given for calculating the absorbed dose in a material from the knowledge of the absorbed dose in another material
exposed to the same radiation field. The procedure is restricted to homogeneous materials composed of the elements for which
absorption coefficients have been tabulated. All 92 natural elements are tabulated in (2). It also requires some knowledge of the
energy spectrum of the radiation field produced by the source under consideration. Generally, the accuracy of this method is limited
by the accuracy to which the energy spectrum of the radiation field is known.
1.3 The results of this practice are only valid if charged particle equilibrium exists in the material and at the depth of interest. Thus,
this practice is not applicable for determining absorbed dose in the immediate vicinity of boundaries between materials of widely
differing atomic numbers. For more information on this topic, see Practice E1249.
4
1.4 Energy transport computer codes exist that are formulated to calculate absorbed dose in materials more precisely than this
method. To use these codes, more effort, time, and expense are required. If the situation warrants, such calculations should be used
rather than the method described here.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 This 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.
1
This practice 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.
Current edition approved Jan. 1, 2014Feb. 1, 2021. Published February 2014March 2021. Originally approved in 1978. Last previous edition approved in 20092014 as
E666-09.-14. DOI: 10.1520/E0666-14.10.1520/E0666-21.
2
The boldface numbers in parentheses refer to the list of references appended to this practice.
3
See also ICRU Report 80. For calculation of absorbed dose in dosimetry systems and materials used in radiation processing, mass attenuation coefficients and mass-energy
absorption coefficients for key elements, compounds and materials used in radiation processing dosimetry over the photon range from 100 keV to 20 MeV are given in
Appendix 1 of that report.
4
Information on and packages of computer codes can be obtained from The Radiation Safety Information Computational Center, Oak Ridge National Laboratory, P.O.
Box 2008, Oak Ridge, TN 37831-6362. This information center collects, organizes, evaluates, and disseminates shielding information related to radiation from reactors,
weapons, and accelerators and to radiation occurring in space.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E666 − 21
2. Referenced Documents
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2.1 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and Dosimetry
E668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining Absorbed Dose in
Radiation-Hardness Testing of Electronic Devices
E1249 Practice for Minimizing Dosim
...
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