ISO 15566:1998

IS0
INTERNATIONAL
STANDARD 15566
First edition
1998-l 2-l 5
Practice for use of the alanine-EPR
dosimetry system
Pratique de I’utilisation d ’un systkme dosimktrique 2 I’alanine utilisant la
rhonance paramagktique 6lectronique
Reference number
IS0 15566: 1998(E)

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ISOl5566:1998( E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies
(IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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. IS0 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.
International Standard IS0 15566 was prepared by the American Society for Testing and Materials (ASTM)
Subcommittee E1O.O1 (as E 1607-94) and was adopted, under a special “fast-track procedure ”, by Technical
Committee ISOTTC 85, Nuclear energy, in parallel with its approval by the IS0 member bodies.
A new ISOfTC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review the
voting comments from the IS0 “Fast-track procedure” and to maintain these standards. The USA holds the
convenership of this working group.
International Standard IS0 15566 is one of 20 standards developed and published by ASTM. The 20 fast-tracked
standards and their associated ASTM desianations are listed below:
4
Title
IS0 Designation ASTM Designation
15554 E 1204-93 Practice for dosimetry in gamma irradiation facilities for food
processing
E 1205-93 Practice for use of a ceric-cerous sulfate dosimetry system
15555
15556 E 1261-94 Guide for selection and calibration of dosimetry systems for
radiation processing
15557 E 1275-93 Practice for use of a radiochromic film dosimetry system
E 1276-96 Practice for use of a polymethylmethacrylate dosimetry system
15558
15559 E 1310-94 Practice for use of a radiochromic optical waveguide dosimetry
system
15560 E 1400-95a Practice for characterization and performance of a high-dose
radiation dosimetry calibration laboratory
15561 E 1401-96 Practice for use of a dichromate dosimetry system
0 IS0 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet iso @ isoch
Printed in Switzerland
ii

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IS0 15566: 1998(E)
@IS0
E1431-91 Practice for dosimetry in electron and bremsstrahlung irradiation
15562
facilities for food processing
E 1538-93 Practice for use of the ethanol-chlorobenzene dosimetry system
15563
15564 E 1539-93 Guide for use of radiation-sensitive indicators
E 1540-93 Practice for use of a radiochromic liquid dosimetry system
15565
15566 E 1607-94 Practice for use of the alanine-EPR dosimetry system
Practice for dosimetry in an X-ray (bremsstrahlung) facility for
15567 E 1608-94
radiation processing
Practice for use of calorimetric dosimetry systems for electron
15568 El631-96
beam dose measurements and dosimeter calibrations
Practice for dosimetry in an electron-beam facility for radiation
15569 E 1649-94
processing at energies between 300 keV and 25 MeV
Practice for use of cellulose acetate dosimetry system
15570 E 1650-94
E 1702-95 Practice for dosimetry in a gamma irradiation facility for radiation
15571
processrng
E 1707-95 Guide for estimating uncertainties in dosimetry for radiation
15572
processing
E 1818-96 Practice for dosimetry in an electron-beam facility for radiation
15573
processing at energies between 80 keV and 300 keV
. . .
III

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0 IS0 IS0 15566:1998(E)
AMERICAN SOCIEN FUR TESTING AND MATERIALS
Designation: E 1607 - 94
1916 Race St. Philadelphia, Pa 19103
#Tb
Reprinted from the AnnGal Book ?f ASTM Standards. Copyright ASTM
If not listed in the current combined index, will appear in the next edition.
Standard Practice for
Use of the Alanine-EPR Dosimetry System’
This standard is issued under the fixed designation E 1607; 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 (t) indicates an editorial change since the last revision or reapproval.
E 1400 Practice for Characterization and Performance of a
1. Scope
High-Dose Gamma-Radiation Dosimetry Calibration
1.1 This practice covers materials description, dosimeter
Laboratory4
preparation, instrumentation, and procedures for using the
E 143 1 Practice for Dosimetry in Electron and Brem-
alanine-EPR dosimetry system for measuring the absorbed
sstrahlung Irradiation Facilities for Food Processing4
dose in materials irradiated with photons and electrons. The
2.2 ICRU Reports?
system is based on electron paramagnetic resonance (EPR)
ICRU Report 14 Radiation Dosimetry: X-Rays and
spectroscopy of the amino acid alanine. It is classified as a
Gamma-Rays with Maximum Photon Energies Between
reference standard dosimetry system (see Guide E 126 1).
0.6 and 50 MeV
1.2 This practice covers alanine-EPR dosimetry systems
ICRU Report 17 Radiation Dosimetry: X-Rays Generated
for dose measurements under the following conditions:
1.2.1 The absorbed dose range is between 1 and 1 O5 Gy. at Potentials of 5 to 150 kV
1.2.2 The absorbed dose rate is up to lo2 Gy s-l for ICRU Report 33 Radiation Quantities and Units
continuous radiation fields and up to lo* Gy s-l for pulsed ICRU Report 34 The Dosimetry of Pulsed Radiation
radiation fields (1, 2).3 ICRU Report 35 Radiation Dosimetry: Electron Beams
1.2.3 The radiation energy range for photons is between with Energies between 1 and 50 MeV
0.1 and 50 MeV and for electrons is between 0.3 and 50 ICRU Report 37 Stopping Powers for Electrons and
MeV (1, 2). Positrons
1.2.4 The irradiation temperature is between -60 and
ICRU Report 44 Tissue Substitutes in Radiation
+9O ”C (2, 3).
Dosimetry and Measurement
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for informa-
3. Terminology
tion only.
1.4 This standard does not purport to address all of the
3.1 Definitions -Appropriate terms may be found in
safety concerns, if any, associated with its use. It is the
Terminology E 170.
responsibility of the user of this standard to establish appro-
3.2 Descriptions of Terms Specific to This Standard.
priate safety and health practices and determine the applica-
3.2.1 alanine dosimeter-a specified quantity and phys-
bility of regulatory limitations prior to use.
ical form of the radiation-sensitive material alanine and any
added inert substance such as a binder.
2. Referenced Documents
3.2.2 alanine-EPR dosimetry system-a system used for
determining absorbed dose, consisting of the alanine dosim-
3 1 ASTM Standards:
eters, an EPR spectrometer, the calibration curve, reference
170 Terminology Relating to Radiation Measurements
and Dosimetry4 standards, and procedures for the system ’s use.
178 Practice for Dealing with Outlying Observations5 3.2.3 calibration curve-graphical or mathematical rela-
668 Practice for Application of Thermoluminescence- tionship, between the EPR signal and absorbed dose, for a
Dosimetry (TLD) Systems for Determining Absorbed given type and batch of alanine dosimeters.
Dose in Radiation-Hardness Testing of Electronic 3.2.4 EPR signal--the peak-to-peak distance of the main
Devices4 amplitude of the EPR spectrum. This signal is proportional
1204 Practice for Dosimetry in Gamma Irradiation to alanine radical concentration in the alanine dosimeter.
Facilities for Food Processing4
3.2.5 EPR spectroscopy-the measurement of resonant
126 1 Guide for the Selection and Application of
absorption of electromagnetic energy resulting from the
Dosimetry Systems for Radiation Processing of Food4
transition of unpaired electrons between different energy
levels, upon application of radiofrequencies to a paramag-
netic substance in the presence of a magnetic field.
I This practice is under the jurisdiction of ASTM Committee E- 10 on Nuclear
3.2.6 EPR spectrum- the first derivative of the electron
Technology and Applications and is the direct responsibility of Subcommittee
paramagnetic absorption spectrum as measured as a function
E 10.0 1 on Dosimetry for Radiation Processing.
Current edition approved April 15, 1994. Published August 1994. of the magnetic field.
2 The term “electron spin resonance” (ESR) is used interchangeably with
3.2.7 zero dose reading-signal measurement of an
electron paramagnetic resonance (EPR).
3 The boldface numbers in parentheses refer to the list of references at the end
of this standard.
4 Annual Book oJASTM Standards, Vol 12.02. 6 Available from International Commission on Radiation Units and Measure-
ments, 79 10 Woodmont Ave., Suite 800, Bethesda, MD 208 14.
5 Annual Book of ASTM Standards, Vol 14.02.

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0 IS0
IS0 15566: 1998(E)
6.3.2 Usual physical shapes are pellets, films, cylinders, or
unirradiated &nine dosimeter with the same EPR spectrom-
eter parameters used for the lowest measurable absorbed cables. The dimensions depend on the inner diameter of the
dose value, microwave cavity of the EPR spectrometer, the dosimeter
holder and, the required precision of the measurement.
4. Significance and Use
6.3.3 The softening point of the binder must be compat-
ible with the temperature during radiation exposure.
4.1 The alanine-EPR dosimetry system provides a reliable
6.3.4 The alanine content can vary. Some published
means for measuring the absorbed dose. It is based on the
values of the alanine content with different binders are
generation of specific stab!e radicals in crystalline alanine by
polyvinylpyrrolidone (95 %) (4), paraffin wax (80 to 90 %)
ionizing radiation.
(2, 5, 6), polystyrene (70 %) (7), ethylene-propylene rubber
4.2 The dosimeter contains crystalline alanine and regis-
(67 %) (8), and low-density polyethylene (60 %)
Q
ters the absorbed dose by an increase in the alanine radical
sensitivity of the dosimeter is proportional to the alanine
concentration. Identification and determination of the con-
content.
centration of the specific alanine radical are performed by
6.3.5 The manufacturing process involves a number of
EPR spectroscopy.
.
operations, for example, mortaring, sieving, binder and
4.3 Measurement of the concentration of free radicals by
lubricant (optional) addition, homogenization, pressing, or
EPR spectroscopy is nondestructive. Alanine dosimeters can
extruding. The introduction of radicals from even small
be read out repeatedly and hence can be used for archival
amounts of paramagnetic material or from mechanical force
purposes.
must be avoided during the manufacturing
NOTE l-For a comprehensive discussion of various dosimetry
fabrication techniques are described in Ref (
methods and materials applicable to the radiation types and energies
6.4 Preparation Quality Assurance.
discussed in this practice, see Practices E 178, E 668, E 1204, E 1400,
E 143 1, Guide E 126 1, and ICRU Reports 14, 17,33,34,35,37, and 44. 6.4.1 Care shall be exercised in conducting dosimeter
preparation. Preparation shall be performed under clean
4.4 Alanine-EPR dosimetry systems are used in industrial
laboratory conditions and with high-quality fabrication pro-
radiation processing, for example, sterilization of medical
cedures as specified in the literature (4). Measurement
devices and pharmaceuticals, preservation of foods, polymer
repeatability, interspecimen variation, and batch sensitivity
modifications, and radiation damage studies in materials, as
may be affected by each process step.
reference or transfer standard or routine dosimetry systems.
6.4.2 Important factors for measurement precision are
5. Dosimeter Material homogeneity, reproducibility of mass, density, size, and
shape of the dosimeters.
5.1 The dosimeter is prepared using cu-alanine, Cl-l,-
6.4.3 Representative sampling of dosimeters shall be per-
CH(NH,)-COOH, in the form of polycrystalline powder.
formed for each production batch and subjected to quality
5.2 Both stereoisomers of cu-alanine are suitable for
control tests, for example, visual tests of surface conditions,
dosimetry; L-alanine is used most commonly.
impact tests, weight tests, and dimensional and density
5.3 The purity of the alanine shall be analytical grade
checks.
(99 % or better). Alanine of appropriate purity is commer-
6.4.4 Dosimetric quality control for each production
cially available. Dopants (a specific trace amount of an
batch includes the mean batch sensitivity and interspecimen
element as additive) are not required.
scattering of the zero-dose-signal dosimeter response.
6. Preparation of Dosimeters 6.4.5 To achieve the accuracy described in 13.3, the
interspecimen variation of the radiation-induced response
6.1 The alanine dosimeter may be used in powdered form
should be within tl % at a 95 % confidence level.
or as a solid compressed with a binder.
NOTE 2-Additives used in the preparation of dosimeters should not
7. Apparatus
add any significant intrinsic or radiation-induced EPR signal. Examples
of suitable binders are cellulose, ethylene-propylene rubber, gelatin,
7.1 The following equipment and instruments are neces-
paraffin,
polyethylene, polyethylene vinyl acetate, polystyrene,
sary to determine the radiation-induced response of the
polyvinylpyrrolidone, polyvinyl propylene, and steak Lubricants
alanine-EPR dosimetry system:
added in the dosimeter manufacturing process are optional. An example
7.1.1 The apparatus comprises an X-band EPR spectrom-
of a suitable lubricant is steak acid.
eter capable of determining the alanine radical concentration
6.2 Powder Dosimeters:
in a dosimeter by measurement of the EPR signal or EPR
6.2.1 Alanine powder may be used directly as supplied by
spectrum. A spectrometer capable of attaining the uncer-
the manufacturer.
tainty limits described in 13.3 over the dose range of 1 to lo5
NOTE &Sieving to achieve a narrower range of grain sizes from
Gy should be capable of the following settings: microwave
several tens to several hundreds of pm is recommended to improve the
frequency 9 to 10 GHz with automatic frequency locking
reproducibility of the EPR signal.
(AFC); corresponding magnetic field to set a g-factor of 2.0
6.2.2 The alanine powder is contained in a sachet or
(at 9.8 GHz, this equals 350 mT; see Note 4) with a field scan
capsule for use. From 50 to 200 mg of powder is typically range of 20 mT about the center field; RF modulation
used for a dosimeter. amplitude 0.1 to 1 mT; microwave power 0.1 to IO mW
6.3 Dosimeters Using Binders. (levelled); variable sweep time, time constant, and receiver
6.3.1 Alanine dosimeters can be prepared by compressing,
gain according to absorbed dose. The sensitivity of the
casting, or extruding a mixture of alanine, binder, and
spectrometer should be at least 2 x 10’ 1 spins/mT. The
lubricant (optional).
cavity should have a sample access diameter of at least 1 mm
2

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IS0 15566:1998(E)
@ IS0
value (see Section 9 of Practice E 668).
greater than the diameter of the dosimeter to be analyzed.
8.2.8 The number of sets of alanine dosimeters required
NOTE 4-The relationship between the microwave frequency and the
to establish the calibration curve of the alanine-EPR
magnetic field at the center of the spectrum is given by
dosimetry system depends on the dose range of utilization.
hv = gp,B
Use at least one set per decade of absorbed dose in the linear
where: range. More sets may be necessary in the non-linear range
= Planck ’s constant, (see 10.1).
h
v = microwave frequency, 8.3 Instrument Setup--Follow manufacturer ’s procedures
= the spectroscopic splitting factor (typically 2.0), for the setup and instrument calibration of salient parame-
g
ters, either by reading the appropriate calibration files or
= the Bohr magneton, and
l-b
B = magnetic field. making the appropriate electromechanical adjustments.
7.1.2 There shall be some mechanical means of posi- 8.4 Routine Spectrometer Performance Checks-Verify
tioning the dosimeter accurately and reproducibly, in terms proper operation of the instrument by comparing the mea-
of both height and centricity in the cavity. The dosimeter surement of a suitable spin standard (which might be an
holder is usually made of fused quartz and should be of such irradiated alanine dosimeter stored under controlled condi-
quality and cleanliness to contribute no interfering EPR tions, a pitch sample, or Mn(I1) in CaO). If there is not
signal. ag
...