ISO/ASTM 51607:2013

Practice for use of the alanine-EPR dosimetry system

ISO/ASTM 51607:2013 covers dosimeter materials, instrumentation, and procedures for using the alanine-EPR dosimetry system for measuring the absorbed dose in the photon and electron radiation processing of materials. The system is based on electron paramagnetic resonance (EPR) spectroscopy of free radicals derived from the amino acid alanine. The alanine dosimeter is classified as a type I dosimeter as it is affected by individual influence quantities in a welldefined way that can be expressed in terms of independent correction factors. The alanine dosimeter may be used in either a reference standard dosimetry system or in a routine dosimetry system. ISO/ASTM 51607:2013 is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM E2628 for alanine dosimetry system. It is intended to be read in conjunction with ASTM E2628.

Pratique de l'utilisation d'un système dosimétrique à l'alanine utilisant la résonance paramagnétique électronique

General Information

• Status: Published
• Publication Date: 14-May-2013
• ICS: 17.240 - Radiation measurements
• Technical Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Drafting Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Current Stage: 9599 - Withdrawal of International Standard
• Due Date: 04-Apr-2025
• Completion Date: 04-Apr-2025

Relations

• Revises: ISO/ASTM 51607:2004 - Practice for use of the alanine-EPR dosimetry system
• Effective Date: 20-Oct-2012

Standards Content (Sample)

INTERNATIONAL ISO/ASTM
STANDARD 51607
Third edition
2013-06-01
Practice for use of an alanine-EPR
dosimetry system
Pratique pour l’utilisation d’un système dosimétrique à l’alanine
utilisant la résonance paramagnétique électronique
Reference number
© ISO/ASTM International 2013
© ISO/ASTM International 2013
Allrightsreserved.Unlessotherwisespecified,nopartofthispublicationmaybereproducedorutilizedinanyformorbyanymeans,electronicormechanical,
including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s member body in the country of the
requester. In the United States, such requests should be sent to ASTM International.
ISO copyright office ASTM International, 100 Barr Harbor Drive, PO Box C700,
Case postale 56 • CH-1211 Geneva 20 West Conshohocken, PA 19428-2959, USA
Tel. [phone] Tel. [phone]
Fax [phone] Fax [phone]
E-mail [e-mail] E-mail [e-mail]
Web www.iso.org Web www.astm.org
Published in Switzerland
ii © ISO/ASTM International 2013 – All rights reserved

ISO/ASTM51607:2013(E)
Contents Page
1 Scope . 1
2 Referenced documents . 1
3 Terminology . 1
4 Significance and use . 2
5 Overview . 2
6 Influence quantities . 2
7 Dosimetry system and its verification . 3
8 Incoming dosimeter stock assessment . 4
9 Calibration procedures . 4
10 Routine use . 4
11 Minimum documentation requirements . 5
12 Measurement uncertainty . 5
13 Keywords . 5
Bibliography . 5
© ISO/ASTM International 2013 – All rights reserved iii

Foreword
ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for
voting. Publication as an International Standard requires approval by at least 75% of the member bodies
casting a vote.
ASTM International is one of the world’s largest voluntary standards development organizations with global
participation from affected stakeholders. ASTM technical committees follow rigorous due process balloting
procedures.
A pilot project between ISO and ASTM International has been formed to develop and maintain a group of
ISO/ASTM radiation processing dosimetry standards. Under this pilot project, ASTM Committee E61,
Radiation Processing, is responsible for the development and maintenance of these dosimetry standards with
unrestricted participation and input from appropriate ISO member bodies.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. Neither ISO nor ASTM International shall be held responsible for identifying any or all such patent
rights.
International Standard ISO/ASTM 51607 was developed by ASTM Committee E61, Radiation Processing,
through Subcommittee E61.02, Dosimetry Systems, and byTechnical Committee ISO/TC 85, Nuclear energy,
nuclear technologies and radiological protection.
This third edition of ISO/ASTM 51607 cancels and replaces ISO/ASTM 51607:2004(E)
iv © ISO/ASTM International 2013 – All rights reserved

An American National Standard
Standard Practice for
Use of an Alanine-EPR Dosimetry System
This standard is issued under the fixed designation ISO/ASTM 51607; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 2. Referenced documents
1.1 This practice covers dosimeter materials, instrumenta- 2.1 ASTM Standards:
tion, and procedures for using the alanine-EPR dosimetry E170 TerminologyRelatingtoRadiationMeasurementsand
system for measuring the absorbed dose in the photon and Dosimetry
electron radiation processing of materials.The system is based E2628 Practice for Dosimetry in Radiation Processing
on electron paramagnetic resonance (EPR) spectroscopy of E2701 Guide for Performance Characterization of Dosim-
free radicals derived from the amino acid alanine. etersandDosimetrySystemsforUseinRadiationProcess-
1.2 The alanine dosimeter is classified as a type I dosimeter ing
as it is affected by individual influence quantities in a well- 2.2 ISO/ASTM Standards:
defined way that can be expressed in terms of independent 51261 Practice for Calibration of Routine Dosimetry Sys-
correction factors (see ASTM Practice E2628). The alanine tems for Radiation Processing
dosimetermaybeusedineitherareferencestandarddosimetry 51707 Guide for Estimating Uncertainties in Dosimetry for
system or in a routine dosimetry system. Radiation Processing
1.3 This document is one of a set of standards that provides 2.3 ICRU Reports:
recommendations for properly implementing dosimetry in ICRU Report 85a Fundamental Quantities and Units for
radiation processing, and describes a means of achieving Ionizing Radiation
compliance with the requirements of ASTM E2628 “Practice ICRU Report 80 Dosimetry Systems for Use in Radiation
for Dosimetry in Radiation Processing” for alanine dosimetry Processing
system. It should be read in conjunction with ASTM E2628. 2.4 Joint Committee for Guides in Metrology (JCGM)
1.4 Thispracticecoversalanine-EPRdosimetrysystemsfor Reports:
dose measurements under the following conditions: JCGM 100:2008, GUM 1995, with minor corrections,
1.4.1 The absorbed dose range is between 1 and 1.5 3 Evaluation of measurement data – Guide to the Expres-
10 Gy. sion of Uncertainty in Measurement
2 -1
1.4.2 The absorbed dose rate is up to 10 Gy s for continu- JCGM100:2008,VIM ,Internationalvocabularyofmetrol-
10 -1
ous radiation fields and up to 3 3 10 Gy s for pulsed ogy – Basis and general concepts and associated terms
radiation fields (1-4).
3. Terminology
1.4.3 The radiation energy for photons and electrons is
between 0.1 and 30 MeV (1, 2, 5-8). 3.1 Definitions:
3.1.1 alanine dosimeter—specified quantity and physical
1.4.4 The irradiation temperature is between –78 °C and +
70 °C (2, 9-12). form of the radiation-sensitive material alanine and any added
1.5 This standard does not purport to address all of the inert substance such as a binder.
3.1.2 alanine-EPR dosimetry system—system used for de-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- termining absorbed dose, consisting of alanine dosimeters, an
EPR spectrometer and its associated reference materials, and
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. procedures for the system’s use.
This practice is under the jurisdiction of ASTM Committee E61 on Radiation
Processing and is the direct responsibility of Subcommittee E61.02 on Dosimetry For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
Systems, and is also under the jurisdiction of ISO/TC 85/WG 3. www.astm.org, or contact ASTM Customer Service at [e-mail]. For
Current edition approved April 9, 2013. Published June 2013. Originally Annual Book of ASTM Standards volume information, refer to the standard’s
ϵ1
published as ASTM E1607–94. Last previous ASTM edition E1607–96 . Document Summary page on the ASTM website.
ASTM E1607–94 was adopted by ISO in 1998 with the intermediate designation Available from International Commission on Radiation Units and Measure-
ISO 15566:1998(E).The present International Standard ISO/ASTM 51607:2013(E) ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, U.S.A.
replaces ISO 15566 and is a major revision of the last previous edition ISO/ASTM DocumentproducedbyWorkingGroup1oftheJointCommitteeforGuidesin
51607–2004(E). Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
The term “electron spin resonance” (ESR) is used interchangeably with www.bipm.org).
electron paramagnetic resonance (EPR). DocumentproducedbyWorkingGroup2oftheJointCommitteeforGuidesin
Theboldfacenumbersinparenthesesrefertothebibliographyattheendofthis Metrology (JCGM/WG 2). Available free of charge at the BIPM website (http://
standard. www.bipm.org).
© ISO/ASTM International 2013 – All rights reserved
3.1.3 alanine-EPR dosimeter response—value resulting 5.4 The dosimeter contains crystalline alanine and registers
from applied adjustments to the EPR signal amplitude. the absorbed dose by the formation of alanine-derived free
radicals (22). Identification and measurement of alanine-
3.1.4 check standard—astandardpreparedindependentlyof
the calibration standards that is measured to verify the perfor- derived free radicals are performed by EPR spectroscopy.
ICRU Report 80 provides information on the scientific basis
mance of a dosimetry system.
and historical development of this dosimetry system.
3.1.5 EPR intensity reference material—a stable paramag-
5.5 The measurement of free radicals by EPR spectroscopy
netic material whose measurement by EPR is applied to the
is nondestructive. This can be repeated and hence can be used
dosimeter EPR signal amplitude as part of the dosimeter
for archival purposes (23-25).
response determination.
3.1.6 EPR signal amplitude—peak-to-peakamplitudeofthe
6. Influence quantities
central signal of the EPR spectrum.
6.1 Factors other than absorbed dose which influence the
3.1.6.1 Discussion—This signal is proportional to the
dosimeter response are referred to as influence quantities, and
alanine-derived free radical concentration in the alanine do-
are discussed in the following sections (see alsoASTM Guide
simeter.
E2701).Examplesofsuchinfluencequantitiesaretemperature
3.1.7 EPR spectroscopy—measurement of resonant absorp-
and dose rate.
tion of electromagnetic energy resulting from the transition of
6.2 Pre-Irradiation Conditions:
unpaired electrons between different energy levels, upon ap-
6.2.1 Dosimeter Conditioning and Packaging—Alaninedo-
plication of radio frequencies to a paramagnetic substance in
simeter conditioning and packaging may be important under
the presence of a magnetic field.
certain conditions (see 6.2.4).
3.1.8 EPR spectrum—first derivative of the electron para-
magnetic absorption spectrum measured as a function of the
NOTE 2—Thesortingofalaninepelletdosimetersbymassintosub-lots
magnetic field. will improve the measurement uncertainty.
3.1.9 zero dose amplitude—EPR signal amplitude of an
6.2.2 Time Since Manufacture—There is no known influ-
unirradiated alanine dosimeter with the same EPR spectrom-
ence of time since manufacture on alanine dosimeters when
eter parameters used for the lowest measurable absorbed dose
stored under recommended conditions.
value.
6.2.3 Temperature—There is no known influence of pre-
3.2 Definitions of other terms used in this standard that
irradiation temperature. However, it is recommended that
pertain to radiation measurement and dosimetry may be found
alanine dosimeters be stored at manufacturer recommended
inASTM Terminology E170. Definitions in E170 are compat-
temperatures. Exposure to temperatures outside the manufac-
ible with ICRU Report 85a; that document, therefore, may be
turer’s recommended range should be avoided to reduce the
used as an alternative reference.
potential for adverse effects on dosimeter response.
6.2.4 Relative Humidity—The humidity during pre-
4. Significance and use
irradiation storage may influence the EPR signal amplitude of
alanine dosimeters (24, 25). The effect of humidity may be
4.1 The alanine-EPR dosimetry system provides a means
reduced by sealing dosimeters in a material impervious to
formeasuringabsorbeddose.Itisbasedonthemeasurementof
water.
specific stable free radicals in crystalline alanine generated by
6.2.5 Exposure to Light—There is no known influence of
ionizing radiation.
ambient light.
4.2 Alanine-EPR dosimetry systems are used in reference-
6.3 Conditions During Irradiation:
or transfer-standard or routine dosimetry systems in radiation
6.3.1 Irradiation Temperature—Theirradiationtemperature
applications that include: sterilization of medical devices and
influences the EPR signal amplitude of alanine dosimeters.
pharmaceuticals, food irradiation, polymer modifications,
medical therapy and radiation damage studies in materials (1,
NOTE 3—The effect of irradiation temperature on the dosimeter EPR
13-15).
signal amplitude may be dependent on the dosimeter type. The tempera-
-1
ture coefficient, R (K ) is described by the relationship, (∆m/m)/∆T,
t
where m is the EPR signal amplitude (in arbitrary units) and T is the
5. Overview
irradiation temperature (in K). For dosimeters with L-alanine, a positive
5.1 The dosimeter is prepared using α-alanine, CH -
temperature coeffici
...

INTERNATIONAL ISO/ASTM
STANDARD 51607
Third edition
2013-06-01
Practice for use of an alanine-EPR
dosimetry system
Pratique pour l’utilisation d’un système dosimétrique à l’alanine
utilisant la résonance paramagnétique électronique
Reference number
© ISO/ASTM International 2013
© ISO/ASTM International 2013
Allrightsreserved.Unlessotherwisespecified,nopartofthispublicationmaybereproducedorutilizedinanyformorbyanymeans,electronicormechanical,
including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s member body in the country of the
requester. In the United States, such requests should be sent to ASTM International.
ISO copyright office ASTM International, 100 Barr Harbor Drive, PO Box C700,
Case postale 56 • CH-1211 Geneva 20 West Conshohocken, PA 19428-2959, USA
Tel. [phone] Tel. [phone]
Fax [phone] Fax [phone]
E-mail [e-mail] E-mail [e-mail]
Web www.iso.org Web www.astm.org
Published in Switzerland
ii © ISO/ASTM International 2013 – All rights reserved

ISO/ASTM51607:2013(E)
Contents Page
1 Scope . 1
2 Referenced documents . 1
3 Terminology . 1
4 Significance and use . 2
5 Overview . 2
6 Influence quantities . 2
7 Dosimetry system and its verification . 3
8 Incoming dosimeter stock assessment . 4
9 Calibration procedures . 4
10 Routine use . 4
11 Minimum documentation requirements . 5
12 Measurement uncertainty . 5
13 Keywords . 5
Bibliography . 5
© ISO/ASTM International 2013 – All rights reserved iii

Foreword
ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for
voting. Publication as an International Standard requires approval by at least 75% of the member bodies
casting a vote.
ASTM International is one of the world’s largest voluntary standards development organizations with global
participation from affected stakeholders. ASTM technical committees follow rigorous due process balloting
procedures.
A pilot project between ISO and ASTM International has been formed to develop and maintain a group of
ISO/ASTM radiation processing dosimetry standards. Under this pilot project, ASTM Committee E61,
Radiation Processing, is responsible for the development and maintenance of these dosimetry standards with
unrestricted participation and input from appropriate ISO member bodies.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. Neither ISO nor ASTM International shall be held responsible for identifying any or all such patent
rights.
International Standard ISO/ASTM 51607 was developed by ASTM Committee E61, Radiation Processing,
through Subcommittee E61.02, Dosimetry Systems, and byTechnical Committee ISO/TC 85, Nuclear energy,
nuclear technologies and radiological protection.
This third edition of ISO/ASTM 51607 cancels and replaces ISO/ASTM 51607:2004(E)
iv © ISO/ASTM International 2013 – All rights reserved

An American National Standard
Standard Practice for
Use of an Alanine-EPR Dosimetry System
This standard is issued under the fixed designation ISO/ASTM 51607; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 2. Referenced documents
1.1 This practice covers dosimeter materials, instrumenta- 2.1 ASTM Standards:
tion, and procedures for using the alanine-EPR dosimetry E170 TerminologyRelatingtoRadiationMeasurementsand
system for measuring the absorbed dose in the photon and Dosimetry
electron radiation processing of materials.The system is based E2628 Practice for Dosimetry in Radiation Processing
on electron paramagnetic resonance (EPR) spectroscopy of E2701 Guide for Performance Characterization of Dosim-
free radicals derived from the amino acid alanine. etersandDosimetrySystemsforUseinRadiationProcess-
1.2 The alanine dosimeter is classified as a type I dosimeter ing
as it is affected by individual influence quantities in a well- 2.2 ISO/ASTM Standards:
defined way that can be expressed in terms of independent 51261 Practice for Calibration of Routine Dosimetry Sys-
correction factors (see ASTM Practice E2628). The alanine tems for Radiation Processing
dosimetermaybeusedineitherareferencestandarddosimetry 51707 Guide for Estimating Uncertainties in Dosimetry for
system or in a routine dosimetry system. Radiation Processing
1.3 This document is one of a set of standards that provides 2.3 ICRU Reports:
recommendations for properly implementing dosimetry in ICRU Report 85a Fundamental Quantities and Units for
radiation processing, and describes a means of achieving Ionizing Radiation
compliance with the requirements of ASTM E2628 “Practice ICRU Report 80 Dosimetry Systems for Use in Radiation
for Dosimetry in Radiation Processing” for alanine dosimetry Processing
system. It should be read in conjunction with ASTM E2628. 2.4 Joint Committee for Guides in Metrology (JCGM)
1.4 Thispracticecoversalanine-EPRdosimetrysystemsfor Reports:
dose measurements under the following conditions: JCGM 100:2008, GUM 1995, with minor corrections,
1.4.1 The absorbed dose range is between 1 and 1.5 3 Evaluation of measurement data – Guide to the Expres-
10 Gy. sion of Uncertainty in Measurement
2 -1
1.4.2 The absorbed dose rate is up to 10 Gy s for continu- JCGM100:2008,VIM ,Internationalvocabularyofmetrol-
10 -1
ous radiation fields and up to 3 3 10 Gy s for pulsed ogy – Basis and general concepts and associated terms
radiation fields (1-4).
3. Terminology
1.4.3 The radiation energy for photons and electrons is
between 0.1 and 30 MeV (1, 2, 5-8). 3.1 Definitions:
3.1.1 alanine dosimeter—specified quantity and physical
1.4.4 The irradiation temperature is between –78 °C and +
70 °C (2, 9-12). form of the radiation-sensitive material alanine and any added
1.5 This standard does not purport to address all of the inert substance such as a binder.
3.1.2 alanine-EPR dosimetry system—system used for de-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- termining absorbed dose, consisting of alanine dosimeters, an
EPR spectrometer and its associated reference materials, and
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. procedures for the system’s use.
This practice is under the jurisdiction of ASTM Committee E61 on Radiation
Processing and is the direct responsibility of Subcommittee E61.02 on Dosimetry For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
Systems, and is also under the jurisdiction of ISO/TC 85/WG 3. www.astm.org, or contact ASTM Customer Service at [e-mail]. For
Current edition approved April 9, 2013. Published June 2013. Originally Annual Book of ASTM Standards volume information, refer to the standard’s
ϵ1
published as ASTM E1607–94. Last previous ASTM edition E1607–96 . Document Summary page on the ASTM website.
ASTM E1607–94 was adopted by ISO in 1998 with the intermediate designation Available from International Commission on Radiation Units and Measure-
ISO 15566:1998(E).The present International Standard ISO/ASTM 51607:2013(E) ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, U.S.A.
replaces ISO 15566 and is a major revision of the last previous edition ISO/ASTM DocumentproducedbyWorkingGroup1oftheJointCommitteeforGuidesin
51607–2004(E). Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
The term “electron spin resonance” (ESR) is used interchangeably with www.bipm.org).
electron paramagnetic resonance (EPR). DocumentproducedbyWorkingGroup2oftheJointCommitteeforGuidesin
Theboldfacenumbersinparenthesesrefertothebibliographyattheendofthis Metrology (JCGM/WG 2). Available free of charge at the BIPM website (http://
standard. www.bipm.org).
© ISO/ASTM International 2013 – All rights reserved
3.1.3 alanine-EPR dosimeter response—value resulting 5.4 The dosimeter contains crystalline alanine and registers
from applied adjustments to the EPR signal amplitude. the absorbed dose by the formation of alanine-derived free
radicals (22). Identification and measurement of alanine-
3.1.4 check standard—astandardpreparedindependentlyof
the calibration standards that is measured to verify the perfor- derived free radicals are performed by EPR spectroscopy.
ICRU Report 80 provides information on the scientific basis
mance of a dosimetry system.
and historical development of this dosimetry system.
3.1.5 EPR intensity reference material—a stable paramag-
5.5 The measurement of free radicals by EPR spectroscopy
netic material whose measurement by EPR is applied to the
is nondestructive. This can be repeated and hence can be used
dosimeter EPR signal amplitude as part of the dosimeter
for archival purposes (23-25).
response determination.
3.1.6 EPR signal amplitude—peak-to-peakamplitudeofthe
6. Influence quantities
central signal of the EPR spectrum.
6.1 Factors other than absorbed dose which influence the
3.1.6.1 Discussion—This signal is proportional to the
dosimeter response are referred to as influence quantities, and
alanine-derived free radical concentration in the alanine do-
are discussed in the following sections (see alsoASTM Guide
simeter.
E2701).Examplesofsuchinfluencequantitiesaretemperature
3.1.7 EPR spectroscopy—measurement of resonant absorp-
and dose rate.
tion of electromagnetic energy resulting from the transition of
6.2 Pre-Irradiation Conditions:
unpaired electrons between different energy levels, upon ap-
6.2.1 Dosimeter Conditioning and Packaging—Alaninedo-
plication of radio frequencies to a paramagnetic substance in
simeter conditioning and packaging may be important under
the presence of a magnetic field.
certain conditions (see 6.2.4).
3.1.8 EPR spectrum—first derivative of the electron para-
magnetic absorption spectrum measured as a function of the
NOTE 2—Thesortingofalaninepelletdosimetersbymassintosub-lots
magnetic field. will improve the measurement uncertainty.
3.1.9 zero dose amplitude—EPR signal amplitude of an
6.2.2 Time Since Manufacture—There is no known influ-
unirradiated alanine dosimeter with the same EPR spectrom-
ence of time since manufacture on alanine dosimeters when
eter parameters used for the lowest measurable absorbed dose
stored under recommended conditions.
value.
6.2.3 Temperature—There is no known influence of pre-
3.2 Definitions of other terms used in this standard that
irradiation temperature. However, it is recommended that
pertain to radiation measurement and dosimetry may be found
alanine dosimeters be stored at manufacturer recommended
inASTM Terminology E170. Definitions in E170 are compat-
temperatures. Exposure to temperatures outside the manufac-
ible with ICRU Report 85a; that document, therefore, may be
turer’s recommended range should be avoided to reduce the
used as an alternative reference.
potential for adverse effects on dosimeter response.
6.2.4 Relative Humidity—The humidity during pre-
4. Significance and use
irradiation storage may influence the EPR signal amplitude of
alanine dosimeters (24, 25). The effect of humidity may be
4.1 The alanine-EPR dosimetry system provides a means
reduced by sealing dosimeters in a material impervious to
formeasuringabsorbeddose.Itisbasedonthemeasurementof
water.
specific stable free radicals in crystalline alanine generated by
6.2.5 Exposure to Light—There is no known influence of
ionizing radiation.
ambient light.
4.2 Alanine-EPR dosimetry systems are used in reference-
6.3 Conditions During Irradiation:
or transfer-standard or routine dosimetry systems in radiation
6.3.1 Irradiation Temperature—Theirradiationtemperature
applications that include: sterilization of medical devices and
influences the EPR signal amplitude of alanine dosimeters.
pharmaceuticals, food irradiation, polymer modifications,
medical therapy and radiation damage studies in materials (1,
NOTE 3—The effect of irradiation temperature on the dosimeter EPR
13-15).
signal amplitude may be dependent on the dosimeter type. The tempera-
-1
ture coefficient, R (K ) is described by the relationship, (∆m/m)/∆T,
t
where m is the EPR signal amplitude (in arbitrary units) and T is the
5. Overview
irradiation temperature (in K). For dosimeters with L-alanine, a positive
5.1 The dosimeter is prepared using α-alanine, CH -
temperature coeffici
...