ASTM E666-09
(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
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.
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 14, 21, and 34.
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) , 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 (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 E 1249.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: E666 − 09
StandardPractice 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 Department of Defense.
1. Scope expense are required. If the situation warrants, such calcula-
tions should be used rather than the method described here.
1.1 This practice presents a technique for calculating the
1.5 This standard does not purport to address all of the
absorbed dose in a material from knowledge of the radiation
2,3
safety concerns, if any, associated with its use. It is the
field, the composition of the material, (1-5) and a related
responsibility of the user of this standard to establish appro-
measurement. The procedure is applicable for X and gamma
priate safety and health practices and determine the applica-
radiation provided the energy of the photons fall within the
bility of regulatory limitations prior to use.
range from 0.01 to 20 MeV.
1.2 A method is given for calculating the absorbed dose in
2. Referenced Documents
a material from the knowledge of the absorbed dose in another
5
2.1 ASTM Standards:
material exposed to the same radiation field. The procedure is
E170Terminology Relating to Radiation Measurements and
restrictedtohomogeneousmaterialscomposedoftheelements
Dosimetry
for which absorption coefficients have been tabulated (2). It
E380Practice for Use of the International System of Units
also requires some knowledge of the energy spectrum of the
6
(SI) (the Modernized Metric System) (Withdrawn 1997)
radiation field produced by the source under consideration.
E668 Practice for Application of Thermoluminescence-
Generally, the accuracy of this method is limited by the
Dosimetry (TLD) Systems for Determining Absorbed
accuracy to which the energy spectrum of the radiation field is
DoseinRadiation-HardnessTestingofElectronicDevices
known.
E1249Practice for Minimizing Dosimetry Errors in Radia-
1.3 The results of this practice are only valid if charged
tionHardnessTestingofSiliconElectronicDevicesUsing
particle equilibrium exists in the material and at the depth of
Co-60 Sources
interest. Thus, this practice is not applicable for determining
2.2 International Commission on Radiation Units and Mea-
absorbeddoseintheimmediatevicinityofboundariesbetween
surements (ICRU) Reports:
materials of widely differing atomic numbers. For more infor-
ICRU Report 14—Radiation Dosimetry: X Rays and
mation on this topic, see Practice E1249.
Gamma Rays with Maximum Photon Energies Between
7
4
0.6 and 60 MeV
1.4 Energy transport computer codes exist that are formu-
ICRU Report 18—Specificationof High Activity Gamma-
lated to calculate absorbed dose in materials more precisely
7
Ray Sources
than this method. To use these codes, more effort, time, and
ICRU Report 21—RadiationDosimetry: Electrons with Ini-
7
tial Energies Between 1 and 50 MeV
7
1 ICRU Report 33—RadiationQuantities and Units
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
7
Technology and Applicationsand is the direct responsibility of Subcommittee
ICRU Report 34—TheDosimetry of Pulsed Radiation
E10.07 on Radiation Dosimetry for Radiation Effects on Materials and Devices.
Current edition approved June 1, 2009. Published June 2009. Originally
3. Terminology
approved in 1997. Last previous edition approved in 2008 as E666-08. DOI:
3.1 energy fluence spectrum(ψE)—the product of the par-
10.1520/E0666-09.
2
The boldface numbers in parentheses refer to the list of references appended to
ticlefluencespectrum(seeTerminologyE170)andtheparticle
this practice.
3
For calculation of absorbed dose in biological materials such as tissue or bone,
5
etc.,ICRUReport14providesmoreinformationandproceduresforamoreaccurate For referenced ASTM standards, visit the ASTM website, www.astm.org, or
calculation than this practice. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4
Information on and packages of computer codes can be obtained from The Standards volume information, refer to the standard’s Document Summary page on
Radiation Safety Information Computational Center, Oak Ridge National the ASTM website.
6
Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6362. This information center The last approved version of this historical standard is referenced on
collects, organizes, evaluates, and disseminates shielding information related to www.astm.org.
7
radiation from reactors, weapons, and accelerators and to radiation occurring in Available from In
...
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:E666–08 Designation: E 666 – 09
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 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
whichabsorptioncoefficientshavebeentabulated(2).Italsorequiressomeknowledgeoftheenergyspectrumoftheradiationfield
producedbythesourceunderconsideration.Generally,theaccuracyofthismethodislimitedbytheaccuracytowhichtheenergy
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.Tousethesecodes,moreeffort,time,andexpensearerequired.Ifthesituationwarrants,suchcalculationsshouldbeused
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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
5
2.1 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and Dosimetry
6
E380 Practice for Use of the International System of Units (SI) (The Modernized Metric System)
E668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining Absorbed Dose in
Radiation-Hardness Testing of Electronic Devices
E1249 Practice for Minimizing Dosimetry Errors in Radiation Hardness Testing of Silicon Electronic Devices Using Co-60
Sources
2.2 International Commission on Radiation Units and Measurements (ICRU) Reports:
7
ICRUReport14—Radiation Dosimetry:XRaysandGammaRayswithMaximumPhotonEnergiesBetween0.6and60MeV
7
ICRU Report 18—Specification of High Activity Gamma-Ray Sources
7
ICRU Report 21—Radiation Dosimetry: Electrons with Initial Energies Between 1 and 50 MeV
7
ICRU Report 33—Radiation Quantities and Units
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 Nov.June 1, 2008.2009. Published JanuaryJune 2009. Originally approved in 1997. Last previous edition approved in 20032008 as
E666–03.E666-08.
2
The boldface numbers in parentheses refer to the list of references appended to this practice.
3
For calculation of absorbed dose in biological materials such as tissue or bone, etc., ICRU Report 14 provides more information and procedures for a more accurate
calculation than this practice.
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.
5
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
6
Withdrawn. The last approved version of this hi
...
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