ASTM E2450-16

Standard Practice for Application of CaF<inf>2</inf>(Mn) Thermoluminescence Dosimeters in Mixed Neutron-Photon Environments

SIGNIFICANCE AND USE
4.1 Electronic devices are typically tested for survivability to gamma radiation in pure gamma-ray fields. Testing electronic device response against neutrons is more complex since there is invariably a gamma-ray component in addition to the neutron field. The gamma-ray response of the electronic device is typically subtracted from the overall response to find the device response to neutrons. This approach to the testing requires a determination of the gamma-ray exposure in the mixed field. To enhance the neutron effects, the radiation field is sometimes selected to have as large a neutron component as possible.  
4.2 CaF2(Mn) TLDs are often used to monitor the gamma-ray dose in mixed neutron/gamma radiation fields. Since the dosimeters are exposed along with the device under test to the mixed field, their response must be corrected for neutrons. In a field rich in neutrons, the uncertainty in the interpretation of the TLD response grows. In fields with relatively few neutrons, the total TLD response may be used to make a correction for gamma response of the device under test. Under this condition, the relative uncertainty in the TLD neutron response is not likely to drive the overall uncertainty in the correction to the electronic device response.  
4.3 This practice gives a means of estimating the response of CaF2(Mn) TLDs to neutrons. This neutron response is then subtracted from the measured response to determine the TLD response due to gamma rays. The procedure has relatively high uncertainty because the neutron response of CaF2(Mn) TLDs may vary depending on the source of the material, and this procedure is a generic calculation applicable to CaF2(Mn) TLDs independent of their manufacturer/source. The neutron response given in this practice is a summary of CaF2(Mn) TLD responses reported in the literature. The associated uncertainty envelops the range of results reported, and includes the variety of CaF2(Mn) TLDs used as well as the uncertainties in the dete...
SCOPE
1.1 This practice describes a procedure for correcting a CaF2(Mn) thermoluminescence dosimeter (TLD) reading for its response to neutrons during the irradiation. The neutron response may be subtracted from the total TLD response to give the gamma-ray response. In fields with a large neutron contribution to the total response, this procedure may result in large uncertainties.  
1.2 More precise experimental techniques may be applied if the uncertainty derived from this practice is larger than the level that the user can accept. These more precise techniques are not discussed here. The references in Section 8 describe some of these techniques.  
1.3 This practice does not discuss effects on the TLD reading from neutron interactions with the material surrounding the TLD and used to ensure a charged particle equilibrium. These effects will depend on the isotopic composition of the surrounding material and its thickness, and on the incident neutron spectrum  (1).2  
1.4 The values stated in SI units are to be regarded as standard.

General Information

• Status: Historical
• Publication Date: 31-May-2016
• ICS: 17.240 - Radiation measurements
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.07 - Radiation Dosimetry for Radiation Effects on Materials and Devices

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: E2450 − 16
Standard Practice for
Application of CaF (Mn) Thermoluminescence Dosimeters in
2
1
Mixed Neutron-Photon Environments
This standard is issued under the fixed designation E2450; 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 Dose in Radiation-HardnessTesting of Electronic Devices
E720 Guide for Selection and Use of Neutron Sensors for
1.1 This practice describes a procedure for correcting a
Determining Neutron Spectra Employed in Radiation-
CaF (Mn) thermoluminescence dosimeter (TLD) reading for
2
Hardness Testing of Electronics
its response to neutrons during the irradiation. The neutron
E721 Guide for Determining Neutron Energy Spectra from
response may be subtracted from the total TLD response to
Neutron Sensors for Radiation-Hardness Testing of Elec-
give the gamma-ray response. In fields with a large neutron
tronics
contribution to the total response, this procedure may result in
E722 PracticeforCharacterizingNeutronFluenceSpectrain
large uncertainties.
Terms of an Equivalent Monoenergetic Neutron Fluence
1.2 More precise experimental techniques may be applied if
for Radiation-Hardness Testing of Electronics
the uncertainty derived from this practice is larger than the
E1854 Practice for Ensuring Test Consistency in Neutron-
level that the user can accept. These more precise techniques
Induced Displacement Damage of Electronic Parts
are not discussed here. The references in Section 8 describe
F1190 Guide for Neutron Irradiation of Unbiased Electronic
some of these techniques.
Components
1.3 This practice does not discuss effects on the TLD
3. Terminology
reading from neutron interactions with the material surround-
3.1 Definitions:
ing the TLD and used to ensure a charged particle equilibrium.
3.1.1 absorbed dose—see Terminology E170.
These effects will depend on the isotopic composition of the
surrounding material and its thickness, and on the incident
3.1.2 exposure—see Terminology E170.
2
neutron spectrum (1).
3.1.3 kerma—see Terminology E170.
1.4 The values stated in SI units are to be regarded as
3.1.4 linear energy transfer (LET)—the energy loss per unit
standard.
distance as a charged particle passes through a material.
3.1.4.1 Discussion—Electrons resulting from gamma-ray
2. Referenced Documents
interactions in a material generally have a low LET. Heavy
3
2.1 ASTM Standards:
charged particles resulting from neutron interactions with a
E170 Terminology Relating to Radiation Measurements and
material generally have a high LET.
Dosimetry
3.1.5 neutron sensitivity m(E)—the ratio of the detector
E666 Practice for CalculatingAbsorbed Dose From Gamma
reading, that is, the effective neutron dose, to the neutron
or X Radiation
fluence. Thus,
E668 Practice for Application of Thermoluminescence-
M E
~ !
Dosimetry (TLD) Systems for Determining Absorbed
m~E! 5 (1)
Φ~E!
where:
1
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
Φ(E) = the neutron fluence, and
Technology and Applications and is the direct responsibility of Subcommittee
E10.07 on Radiation Dosimetry for Radiation Effects on Materials and Devices.
M(E) = the apparent dose (light output) in the TLD caused
CurrenteditionapprovedJune1,2016.PublishedJuly2016.Originallyapproved
by neutrons of energy E.
in 2005. Last previous edition approved in 2011 as E2450 – 11. DOI: 10.1520/
E2450-16.
4. Significance and Use
2
The boldface numbers in parentheses refer to the list of references at the end of
this standard.
4.1 Electronic devices are typically tested for survivability
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
to gamma radiation in pure gamma-ray fields. Testing elec-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
tronic device response against neutrons is more complex since
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. there is invariably a gamma-ray component in addition to the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E2450 − 16
neutron field.The gamma-ray response of the electronic device 5.3 The neutron spectrum must be known (see Guides E720
is typically subtracted from the overall response to find the and E721). This may be determined in a separate exposure. A
device response to neutrons. This approach to the testing neutron monitor should be used on the irradiation along with
requires a determination of the gamma-ray exposure in the the device un
...

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: E2450 − 11 E2450 − 16
Standard Practice for
Application of CaF (Mn) Thermoluminescence Dosimeters in
2
1
Mixed Neutron-Photon Environments
This standard is issued under the fixed designation E2450; 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 This practice describes a procedure for correcting a CaF (Mn) thermoluminescence dosimeter (TLD) reading for its
2
response to neutrons during the irradiation. The neutron response may be subtracted from the total TLD response to give the
gamma-ray response. In fields with a large neutron contribution to the total response, this procedure may result in large
uncertainties.
1.2 More precise experimental techniques may be applied if the uncertainty derived from this practice is larger than the level
that the user can accept. These more precise techniques are not discussed here. The references in Section 8 describe some of these
techniques.
1.3 This practice does not discuss effects on the TLD reading from neutron interactions with the material surrounding the TLD
and used to ensure a charged particle equilibrium. These effects will depend on the isotopic composition of the surrounding
2
material and its thickness, and on the incident neutron spectrum (1).
1.4 The values stated in SI units are to be regarded as standard.
2. Referenced Documents
3
2.1 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and Dosimetry
E666 Practice for Calculating Absorbed Dose From Gamma or X Radiation
E668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining Absorbed Dose in
Radiation-Hardness Testing of Electronic Devices
E720 Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness
Testing of Electronics
E721 Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics
E722 Practice for Characterizing Neutron Fluence Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence for
Radiation-Hardness Testing of Electronics
E1854 Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts
F1190 Guide for Neutron Irradiation of Unbiased Electronic Components
3. Terminology
3.1 Definitions:
3.1.1 absorbed dose—see Terminology E170.
3.1.2 exposure—see Terminology E170.
3.1.3 kerma—see Terminology E170.
3.1.4 linear energy transfer (LET)—the energy loss per unit distance as a charged particle passes through a material. Electrons
resulting from gamma-ray interactions in a material generally have a low LET. Heavy charged particles resulting from neutron
interactions with a material generally have a high LET.
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. 1, 2011June 1, 2016. Published November 2011July 2016. Originally approved in 2005. Last previous edition approved in 20062011 as
E2450E2450 – 11.-06. DOI: 10.1520/E2450-11.10.1520/E2450-16.
2
The boldface numbers in parentheses refer to the list of references at the end of this standard.
3
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 ----------------------
E2450 − 16
3.1.4.1 Discussion—
Electrons resulting from gamma-ray interactions in a material generally have a low LET. Heavy charged particles resulting from
neutron interactions with a material generally have a high LET.
3.1.5 neutron sensitivity m(E)—the ratio of the detector reading, that is, the effective neutron dose, to the neutron fluence. Thus,
M E
~ !
m E 5 (1)
~ !
Φ~E!
where:
Φ(E) = the neutron fluence, and
M(E) = the apparent dose (light output) in the TLD caused by neutrons of energy E.
4. Significance and Use
4.1 Electronic devices are typically tested for survivability to gamma radiation in pure gamma-ray fields. Testing electro
...