ASTM E1250-15

Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices

SIGNIFICANCE AND USE
4.1 Although Co-60 nuclei only emit monoenergetic gamma rays at 1.17 and 1.33 MeV, the finite thickness of sources, and encapsulation materials and other surrounding structures that are inevitably present in irradiators can contribute a substantial amount of low-energy gamma radiation, principally by Compton scattering (1, 2).3 In radiation-hardness testing of electronic devices this low-energy photon component of the gamma spectrum can introduce significant dosimetry errors for a device under test since the equilibrium absorbed dose as measured by a dosimeter can be quite different from the absorbed dose deposited in the device under test because of absorbed dose enhancement effects (3, 4). Absorbed dose enhancement effects refer to the deviations from equilibrium absorbed dose caused by non-equilibrium electron transport near boundaries between dissimilar materials.  
4.2 The ionization chamber technique described in this method provides an easy means for estimating the importance of the low-energy photon component of any given irradiator type and configuration.  
4.3 When there is an appreciable low-energy spectral component present in a particular irradiator configuration, special experimental techniques should be used to ensure that dosimetry measurements adequately represent the absorbed dose in the device under test. (See Practice E1249.)
SCOPE
1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this chamber.  
1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 × 10 −6 to 3 × 10−2 C kg −1 s−1 (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the exposure rate is >100 R/s, see Appendix X1.  
Note 1: See Terminology E170 for definition of exposure and its units.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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-2015
• ICS: 31.020 - Electronic components in general
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.07 - Radiation Dosimetry for Radiation Effects on Materials and Devices

Relations

• Replaces: ASTM E1250-10 - Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices
• Effective Date: 01-Jun-2015
• Replaced By: ASTM E1250-15(2020) - Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices
• Effective Date: 01-Jul-2020
• Referred By: ASTM F1892-12(2018) - Standard Guide for Ionizing Radiation (Total Dose) Effects Testing of Semiconductor Devices
• Effective Date: 01-Jun-2015
• Referred By: ASTM E1249-15(2021) - Standard Practice for Minimizing Dosimetry Errors in Radiation Hardness Testing of Silicon Electronic Devices Using Co-60 Sources
• Effective Date: 01-Jun-2015
• Referred By: ASTM F1190-18 - Standard Guide for Neutron Irradiation of Unbiased Electronic Components
• Effective Date: 01-Jun-2015
• Referred By: ASTM E1854-19 - Standard Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts
• Effective Date: 01-Jun-2015

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: E1250 − 15
Standard Test Method for
Application of Ionization Chambers to Assess the Low
Energy Gamma Component of Cobalt-60 Irradiators Used in
1
Radiation-Hardness Testing of Silicon Electronic Devices
This standard is issued under the fixed designation E1250; 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 Dosimetry (TLD) Systems for Determining Absorbed
DoseinRadiation-HardnessTestingofElectronicDevices
1.1 Low energy components in the photon energy spectrum
E1249Practice for Minimizing Dosimetry Errors in Radia-
ofCo-60irradiatorsleadtoabsorbeddoseenhancementeffects
tionHardnessTestingofSiliconElectronicDevicesUsing
in the radiation-hardness testing of silicon electronic devices.
Co-60 Sources
These low energy components may lead to errors in determin-
ing the absorbed dose in a specific device under test. This
3. Terminology
method covers procedures for the use of a specialized ioniza-
3.1 absorbed dose enhancement factor— ratio of the ab-
tion chamber to determine a figure of merit for the relative
sorbed dose at a point in a material of interest to the
importance of such effects. It also gives the design and
equilibrium absorbed dose in that same material.
instructions for assembling this chamber.
3.2 average absorbed dose—mass-weighted mean of the
1.2 This method is applicable to measurements in Co-60
−6
absorbed dose over a region of interest.
radiation fields where the range of exposure rates is 7×10
−2 −1 −1
to3×10 Ckg s (approximately100R/hto100R/s).For
3.3 average absorbed dose enhancement factor—ratio of
guidance in applying this method to radiation fields where the
the average absorbed dose in a region of interest to the
exposure rate is >100 R/s, see Appendix X1.
equilibrium absorbed dose.
NOTE1—SeeTerminologyE170fordefinitionofexposureanditsunits.
3.4 dosimeter—any device used to determine the equilib-
rium absorbed dose in the material and at the irradiation
1.3 The values stated in SI units are to be regarded as the
position of interest. Examples of such devices include ther-
standard. The values given in parentheses are for information
moluminescence dosimeters (TLDs), liquid chemical
only.
dosimeters, and radiochromic dye films. (See Practice E668,
1.4 This standard does not purport to address all of the
for a discussion of TLDs.)
safety concerns, if any, associated with its use. It is the
3.5 equilibrium absorbed dose—absorbed dose at some
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- incremental volume within the material in which the condition
of charged particle equilibrium (the energies, number, and
bility of regulatory limitations prior to use.
direction of charged particles induced by the radiation are
2. Referenced Documents
constant throughout the volume) exists. (See Terminology
2
E170.)
2.1 ASTM Standards:
E170Terminology Relating to Radiation Measurements and
4. Significance and Use
Dosimetry
E668Practice for Application of Thermoluminescence-
4.1 AlthoughCo-60nucleionlyemitmonoenergeticgamma
rays at 1.17 and 1.33 MeV, the finite thickness of sources, and
encapsulation materials and other surrounding structures that
1
This method is under the jurisdiction of ASTM Committee E10 on Nuclear
areinevitablypresentinirradiatorscancontributeasubstantial
Technology and Applicationsand is the direct responsibility of Subcommittee
amount of low-energy gamma radiation, principally by Comp-
E10.07 on Radiation Dosimetry for Radiation Effects on Materials and Devices.
3
Current edition approved June 1, 2015. Published August 2015. Originally tonscattering (1, 2). Inradiation-hardnesstestingofelectronic
approved in 1988. Last previous approved in 2010 as E1250-10. DOI: 10.1520/
devices this low-energy photon component of the gamma
E1250-15.
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 the list of references appended to
the ASTM website. this test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E1250 − 15
Other equivalent twinaxial cable types can be used, but the applicable
spectrum can introduce significant dosimetry errors for a
dimensionsoftheionizationchamberbody,clamp,stem,andcableclamp
device under test since the equilibrium a
...

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: E1250 − 10 E1250 − 15
Standard Test Method for
Application of Ionization Chambers to Assess the Low
Energy Gamma Component of Cobalt-60 Irradiators Used in
1
Radiation-Hardness Testing of Silicon Electronic Devices
This standard is issued under the fixed designation E1250; 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.
1. Scope
1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in
the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the
absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to
determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this
chamber.
−6
1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 × 10 to
−2 −1 −1
3 × 10 C kg s (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the
exposure rate is >100 R/s, see Appendix X1.
NOTE 1—See Terminology E170 for definition of exposure and its units.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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
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
3. Terminology
3.1 absorbed dose, D—quotient of dε by dm, where dε is the mean energy imparted by ionizing radiation to the matter in a
¯ ¯
volume element and dm is the mass of matter in that volume element.
D 5 d¯ε/dm (1)
3.1 absorbed dose enhancement factor— ratio of the absorbed dose at a point in a material of interest to the equilibrium
absorbed dose in that same material.
3.2 average absorbed dose—mass-weighted mean of the absorbed dose over a region of interest.
3.3 average absorbed dose enhancement factor—ratio of the average absorbed dose in a region of interest to the equilibrium
absorbed dose.
1
This method is under the jurisdiction of ASTM Committee E10 on Nuclear Technology and Applicationsand is the direct responsibility of Subcommittee E10.07 on
Radiation Dosimetry for Radiation Effects on Materials and Devices.
Current edition approved Dec. 1, 2010June 1, 2015. Published January 2011August 2015. Originally approved in 1988. Last previous approved in 20052010 as
E1250-88(2005).E1250-10. DOI: 10.1520/E1250-10.10.1520/E1250-15.
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 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, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1250 − 15
3.4 dosimeter—any device used to determine the equilibrium absorbed dose in the material and at the irradiation position of
interest. Examples of such devices include thermoluminescence dosimeters (TLDs), liquid chemical dosimeters, and radiochromic
dye films. (See Practice E668, for a discussion of TLDs.)
3.5 equilibrium absorbed dose—absorbed dose at some incremental volume within the material in which the condition of
charged particle equilibrium (the energies, number, and direction of charged particles induced by the radiation are constant
throughout the volume) exists. (See Terminology E170.)
4. Significance and Use
4.1 Although Co-60 nuclei only emit monoenergetic gamma rays at 1.17 and 1.33 MeV, the finite thickness of sources, and
encapsulation materials and other
...