ASTM E521-96(2009)e2
(Practice)Standard Practice for Neutron Radiation Damage Simulation by Charged-Particle Irradiation
Standard Practice for Neutron Radiation Damage Simulation by Charged-Particle Irradiation
SIGNIFICANCE AND USE
4.1 A characteristic advantage of charged-particle irradiation experiments is precise, individual, control over most of the important irradiation conditions such as dose, dose rate, temperature, and quantity of gases present. Additional attributes are the lack of induced radioactivation of specimens and, in general, a substantial compression of irradiation time, from years to hours, to achieve comparable damage as measured in displacements per atom (dpa). An important application of such experiments is the investigation of radiation effects in not-yet-existing environments, such as fusion reactors.
4.2 The primary shortcoming of ion bombardments stems from the damage rate, or temperature dependences of the microstructural evolutionary processes in complex alloys, or both. It cannot be assumed that the time scale for damage evolution can be comparably compressed for all processes by increasing the displacement rate, even with a corresponding shift in irradiation temperature. In addition, the confinement of damage production to a thin layer just (often ∼ 1 μm) below the irradiated surface can present substantial complications. It must be emphasized, therefore, that these experiments and this practice are intended for research purposes and not for the certification or the qualification of equipment.
4.3 This practice relates to the generation of irradiation-induced changes in the microstructure of metals and alloys using charged particles. The investigation of mechanical behavior using charged particles is covered in Practice E821.
SCOPE
1.1 This practice provides guidance on performing charged-particle irradiations of metals and alloys. It is generally confined to studies of microstructural and microchemical changes carried out with ions of low-penetrating power that come to rest in the specimen. Density changes can be measured directly and changes in other properties can be inferred. This information can be used to estimate similar changes that would result from neutron irradiation. More generally, this information is of value in deducing the fundamental mechanisms of radiation damage for a wide range of materials and irradiation conditions.
1.2 The word simulation is used here in a broad sense to imply an approximation of the relevant neutron irradiation environment. The degree of conformity can range from poor to nearly exact. The intent is to produce a correspondence between one or more aspects of the neutron and charged particle irradiations such that fundamental relationships are established between irradiation or material parameters and the material response.
1.3 The practice appears as follows:
Section
Apparatus
4
Specimen Preparation
5 – 10
Irradiation Techniques (including Helium Injection)
11–12
Damage Calculations
13
Postirradiation Examination
14 – 16
Reporting of Results
17
Correlation and Interpretation
18 – 22
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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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´2
Designation: E521 − 96 (Reapproved 2009)
Standard Practice for
Neutron Radiation Damage Simulation by Charged-Particle
Irradiation
This standard is issued under the fixed designation E521; 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.
ε NOTE—Editorial corrections were made in Section 14 in November 2012.
ε NOTE—Editorial corrections were made in 13.1 and 14.4.1.1 in October 2015.
INTRODUCTION
Thispracticeisintendedtoprovidethenuclearresearchcommunitywithrecommendedprocedures
for the simulation of neutron radiation damage by charged-particle irradiation. It recognizes the
diversity of energetic-ion producing devices, the complexities in experimental procedures, and the
difficulties in correlating the experimental results with those produced by reactor neutron irradiation.
Such results may be used to estimate density changes and the changes in microstructure that would
be caused by neutron irradiation. The information can also be useful in elucidating fundamental
mechanisms of radiation damage in reactor materials.
1. Scope
Section
Apparatus 4
1.1 Thispracticeprovidesguidanceonperformingcharged- Specimen Preparation 5–10
Irradiation Techniques (including Helium Injection) 11–12
particle irradiations of metals and alloys. It is generally
Damage Calculations 13
confined to studies of microstructural and microchemical
Postirradiation Examination 14–16
Reporting of Results 17
changes carried out with ions of low-penetrating power that
Correlation and Interpretation 18–22
cometorestinthespecimen.Densitychangescanbemeasured
1.4 The values stated in SI units are to be regarded as
directly and changes in other properties can be inferred. This
standard. No other units of measurement are included in this
informationcanbeusedtoestimatesimilarchangesthatwould
standard.
result from neutron irradiation. More generally, this informa-
1.5 This standard does not purport to address all of the
tion is of value in deducing the fundamental mechanisms of
safety concerns, if any, associated with its use. It is the
radiation damage for a wide range of materials and irradiation
responsibility of the user of this standard to establish appro-
conditions.
priate safety and health practices and determine the applica-
1.2 The word simulation is used here in a broad sense to
bility of regulatory limitations prior to use.
imply an approximation of the relevant neutron irradiation
2. Referenced Documents
environment.Thedegreeofconformitycanrangefrompoorto
nearly exact. The intent is to produce a correspondence
2.1 ASTM Standards:
between one or more aspects of the neutron and charged
C859Terminology Relating to Nuclear Materials
particle irradiations such that fundamental relationships are E170Terminology Relating to Radiation Measurements and
established between irradiation or material parameters and the
Dosimetry
material response. E821Practice for Measurement of Mechanical Properties
During Charged-Particle Irradiation
1.3 The practice appears as follows:
E910Test Method for Application and Analysis of Helium
Accumulation Fluence Monitors for Reactor Vessel
Surveillance, E706 (IIIC)
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
Technology and Applicationsand is the direct responsibility of Subcommittee
E10.08 on Procedures for Neutron Radiation Damage Simulation. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Aug. 1, 2009. Published September 2009. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
ε1
approved in 1976. Last previous edition approved in 2003 as E521–96(2003) . Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E0521-96R09E02. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´2
E521 − 96 (2009)
E942Guide for Simulation of Helium Effects in Irradiated temperature, and quantity of gases present. Additional attri-
Metals butesarethelackofinducedradioactivationofspecimensand,
in general, a substantial compression of irradiation time, from
3. Terminology years to hours, to achieve comparable damage as measured in
displacements per atom (dpa). An important application of
3.1 Definitions of Terms Specific to This Standard:
such experiments is the investigation of radiation effects in
3.1.1 Descriptions of relevant terms are found in Terminol-
not-yet-existing environments, such as fusion reactors.
ogy C859 and Terminology E170.
3.2 Definitions:
4.2 The primary shortcoming of ion bombardments stems
3.2.1 damage energy, n—that portion of the energy lost by from the damage rate, or temperature dependences of the
an ion moving through a solid that is transferred as kinetic
microstructural evolutionary processes in complex alloys, or
energy to atoms of the medium; strictly speaking, the energy both. It cannot be assumed that the time scale for damage
transfer in a single encounter must exceed the energy required
evolution can be comparably compressed for all processes by
to displace an atom from its lattice cite. increasing the displacement rate, even with a corresponding
shift in irradiation temperature. In addition, the confinement of
3.2.2 displacement, n—the process of dislodging an atom
damage production to a thin layer just (often ; 1 µm) below
from its normal site in the lattice.
the irradiated surface can present substantial complications. It
3.2.3 path length, n—the total length of path measured
must be emphasized, therefore, that these experiments and this
along the actual path of the particle.
practice are intended for research purposes and not for the
3.2.4 penetration depth, n—a projection of the range along
certification or the qualification of equipment.
the normal to the entry face of the target.
4.3 This practice relates to the generation of irradiation-
3.2.5 projected range, n—the projection of the range along
induced changes in the microstructure of metals and alloys
the direction of the incidence ion prior to entering the target.
using charged particles. The investigation of mechanical be-
3.2.6 range, n—the distance from the point of entry at the
havior using charged particles is covered in Practice E821.
surface of the target to the point at which the particle comes to
5. Apparatus
rest.
5.1 Accelerator—The major item is the accelerator, which
3.2.7 stopping power (or stopping cross section), n—the
in size and complexity dwarfs any associated equipment.
energy lost per unit path length due to a particular process;
Therefore, it is most likely that irradiations will be performed
usually expressed in differential form as−dE/dx.
at a limited number of sites where accelerators are available (a
3.2.8 straggling, n—the statistical fluctuation due to atomic
1-MeV electron microscope may also be considered an accel-
or electronic scattering of some quantity such as particle range
erator).
or particle energy at a given depth.
5.2 Fixtures for holding specimens during irradiation are
3.3 Symbols:
generally custom-made as are devices to measure and control
3.3.1 A,Z —the atomic weight and the number of the
1 1
particle energy, particle flux, and specimen temperature. Deci-
bombarding ion.
sions regarding apparatus are therefore left to individual
A,Z —the atomic weight and number of the atoms of the
2 2
workerswiththerequestthataccuratedataontheperformance
medium undergoing irradiation.
of their equipment be reported with their results.
depa—damage energy per atom; a unit of radiation expo-
sure. It can be expressed as the product of σ¯ and the fluence.
6. Composition of Specimen
de
dpa—displacements per atom; a unit of radiation exposure
6.1 An elemental analysis of stock from which specimens
giving the mean number of times an atom is displaced from its
are fabricated should be known. The manufacturer’s heat
lattice site. It can be expressed as the product of σ¯ and the
d
number and analysis are usually sufficient in the case of
fluence.
commercally produced metals. Additional analysis should be
heavy ion—used here to denote an ion of mass >4.
performed after other steps in the experimental procedure if
light ion—an arbitrary designation used here for conve-
there is cause to believe that the composition of the specimen
nience to denote an ion of mass ≤4.
may have been altered. It is desirable that uncertainties in the
T —an effective value of the energy required to displace an
d
analyses be stated and that an atomic basis be reported in
atom from its lattice site.
addition to a weight basis.
σ (E)—an energy-dependent displacement cross section; σ¯
d d
denotes a spectrum-averaged value. Usual unit is barns. 7. Preirradiation Heat Treatment of Specimen
σ (E)—an energy-dependent damage energy cross section;
de
7.1 Temperature and time of heat treatments should be well
σ¯ denotes a spectrum-averaged value. Usual unit is barns-eV
de
controlled and reported. This applies to intermediate anneals
or barns-keV.
during fabrication, especially if a metal specimen is to be
irradiated in the cold-worked condition, and it also applies to
4. Significance and Use
operations where specimens are bonded to metal holders by
4.1 A characteristic advantage of charged-particle irradia- diffusion or by brazing. The cooling rate between annealing
tionexperimentsisprecise,individual,controlovermostofthe steps and between the final annealing temperature and room
important irradiation conditions such as dose, dose rate, temperature should also be controlled and reported.
´2
E521 − 96 (2009)
7.2 The environment of the specimen during heat treatment be described in terms of grain size, phases, precipitates,
should be reported. This includes description of container, dislocations, and inclusions.
measureofvacuum,presenceofgases(flowingorsteady),and
9.2 Asectionofarepresentativespecimencutparalleltothe
the presence of impurity absorbers such as metal sponge.Any
particle beam should be examined by light microscopy.Atten-
discoloration of specimens following an anneal should be
tion should be devoted to the microstructure within a distance
reported.
from the incident surface equal to the range of the particle, as
7.3 High-temperature annealing of metals and alloys from well as to the flatness of the surface.
Groups IV, V, and VI frequently results in changes, both
10. Surface Condition of Specimen
positive and negative, in their interstitial impurity content.
Since the impurity content may have a significant influence on
10.1 The surface of the specimen should be clean and flat.
void formation, an analysis of the specimen or of a companion
Details of its preparation should be reported. Electropolishing
piecepriortoirradiationshouldbeperformed.Othersituations,
of metallic specimens is a convenient way of achieving these
such as selective vaporization of alloy constituents during
objectives in a single operation. The possibility that hydrogen
annealing, would also require a final analysis.
is absorbed by the specimen during electropolishing should be
investigated by analyses of polished and nonpolished speci-
7.4 The need for care with regard to alterations in compo-
mens. Deviations in the surface form the perfect-planar condi-
sition is magnified by the nature of the specimens. They are
tion should not exceed, in dimension perpendicular to the
usually very thin with a high exposed surface-to-volume ratio.
plane, 10% of the expected particle range in the specimen.
Information is obtained from regions whose distance from the
surface may be small relative to atomic diffusion distances.
10.2 The specimen may be irradiated in a mechanically
polished condition provided damage produced by polishing
8. Plastic Deformation of Specimen
does not extend into the region of postirradiation examination.
8.1 When plastic deformation is a variable in radiation
damage, care must be taken in the geometrical measurements 11. Dimension of Specimen Parallel to Particle Beam
used to compute the degree of deformation. The variations in
11.1 Specimens without support should be thick enough to
dimensions of the larger piece from which specimens are cut
resist deformation during handling. If a disk having a diameter
should be measured and reported to such a precision that a
of 3 mm is used, its thickness should be greater than 0.1 mm.
standard deviation in the degree of plastic deformation can be
11.2 Supportedspecimensmaybeconsiderablythinnerthan
assigned to the specimens. A measuring device more accurate
unsupported specimens. The minimum thickness should be at
and precise than the common hand micrometer will probably
least fourfold greater than the distance below any surface from
be necessary due to the thinness of specimens commonly
which significant amounts of radiation-produced defects could
irradiated.
escape.Thisdistancecansometimesbeobservedasavoid-free
8.2 The term cold-worked should not stand alone as a
zone near the free surface of an irradiated specimen.
description of state of deformation. Every effort should be
made to characterize completely the deformation. The param-
12. Helium
eters which should be stated are: (1) deformation process (for
12.1 Injection:
example, simple tension or compression, swaging, rolling,
12.1.1 Alpha-particle irradiation is frequently used to inject
rolling with applied tension); (2) total extent of deformation,
helium into specimens to simulate the production of helium
expressed in terms of the principal orthogonal natural strain
during neutron irradiations where helium is produced by
components(ε , ε , ε )orthegeometricshapechangesthatwill
1 2 3
transmutation reactions. Helium injection may be completed
allow the reader to compute the strains; (3) procedure used to
before particle irradiation begins. It may also proceed incre-
reach the total strain level (for example, number of rolling
mentally during interruptions in the particle irradiation or it
passes and reductions in each); (4) strain rate; and (5) defor-
may proceed simultaneously with particle irradiation. The last
mation temperature, including an estimate of temperature
case is the most desirable as it gives the closest simulation to
changes caused by adiabatic work.
neutron irradiation. Some techniques for introducing helium
8.2.1 Many commonly used deformation processes (for
are set forth in Guide E942.
example, rolling and swaging) tend to be nonhomogeneous. In
12.1.2 The influence of implantation temperature on helium
such ca
...
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.
´2 ´2
Designation: E521 − 96 (Reapproved 2009) E521 − 96 (Reapproved 2009)
Standard Practice for
Neutron Radiation Damage Simulation by Charged-Particle
Irradiation
This standard is issued under the fixed designation E521; 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.
ε NOTE—Editorial corrections were made in Section 14 in November 2012.
ε NOTE—Editorial corrections were made in 13.1 and 14.4.1.1 in October 2015.
INTRODUCTION
This practice is intended to provide the nuclear research community with recommended procedures
for the simulation of neutron radiation damage by charged-particle irradiation. It recognizes the
diversity of energetic-ion producing devices, the complexities in experimental procedures, and the
difficulties in correlating the experimental results with those produced by reactor neutron irradiation.
Such results may be used to estimate density changes and the changes in microstructure that would
be caused by neutron irradiation. The information can also be useful in elucidating fundamental
mechanisms of radiation damage in reactor materials.
1. Scope
1.1 This practice provides guidance on performing charged-particle irradiations of metals and alloys. It is generally confined to
studies of microstructural and microchemical changes carried out with ions of low-penetrating power that come to rest in the
specimen. Density changes can be measured directly and changes in other properties can be inferred. This information can be used
to estimate similar changes that would result from neutron irradiation. More generally, this information is of value in deducing the
fundamental mechanisms of radiation damage for a wide range of materials and irradiation conditions.
1.2 The word simulation is used here in a broad sense to imply an approximation of the relevant neutron irradiation
environment. The degree of conformity can range from poor to nearly exact. The intent is to produce a correspondence between
one or more aspects of the neutron and charged particle irradiations such that fundamental relationships are established between
irradiation or material parameters and the material response.
1.3 The practice appears as follows:
Section
Apparatus 4
Specimen Preparation 5 – 10
Irradiation Techniques (including Helium Injection) 11–12
Damage Calculations 13
Postirradiation Examination 14 – 16
Reporting of Results 17
Correlation and Interpretation 18 – 22
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear Technology and Applicationsand is the direct responsibility of Subcommittee E10.08 on
Procedures for Neutron Radiation Damage Simulation.
ε1
Current edition approved Aug. 1, 2009. Published September 2009. Originally approved in 1976. Last previous edition approved in 2003 as E521 – 96 (2003) . DOI:
10.1520/E0521-96R09E01.10.1520/E0521-96R09E02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´2
E521 − 96 (2009)
2. Referenced Documents
2.1 ASTM Standards:
C859 Terminology Relating to Nuclear Materials
E170 Terminology Relating to Radiation Measurements and Dosimetry
E821 Practice for Measurement of Mechanical Properties During Charged-Particle Irradiation
E910 Test Method for Application and Analysis of Helium Accumulation Fluence Monitors for Reactor Vessel Surveillance,
E706 (IIIC)
E942 Guide for Simulation of Helium Effects in Irradiated Metals
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 Descriptions of relevant terms are found in Terminology C859 and Terminology E170.
3.2 Definitions:
3.2.1 damage energy, n—that portion of the energy lost by an ion moving through a solid that is transferred as kinetic energy
to atoms of the medium; strictly speaking, the energy transfer in a single encounter must exceed the energy required to displace
an atom from its lattice cite.
3.2.2 displacement, n—the process of dislodging an atom from its normal site in the lattice.
3.2.3 path length, n—the total length of path measured along the actual path of the particle.
3.2.4 penetration depth, n—a projection of the range along the normal to the entry face of the target.
3.2.5 projected range, n—the projection of the range along the direction of the incidence ion prior to entering the target.
3.2.6 range, n—the distance from the point of entry at the surface of the target to the point at which the particle comes to rest.
3.2.7 stopping power (or stopping cross section), n—the energy lost per unit path length due to a particular process; usually
expressed in differential form as − dE/dx.
3.2.8 straggling, n—the statistical fluctuation due to atomic or electronic scattering of some quantity such as particle range or
particle energy at a given depth.
3.3 Symbols:
3.3.1 A , Z —the atomic weight and the number of the bombarding ion.
1 1
A , Z —the atomic weight and number of the atoms of the medium undergoing irradiation.
2 2
depa—damage energy per atom; a unit of radiation exposure. It can be expressed as the product of σ¯ and the fluence.
de
dpa—displacements per atom; a unit of radiation exposure giving the mean number of times an atom is displaced from its lattice
site. It can be expressed as the product of σ¯ and the fluence.
d
heavy ion—used here to denote an ion of mass >4.
light ion—an arbitrary designation used here for convenience to denote an ion of mass ≤4.
T —an effective value of the energy required to displace an atom from its lattice site.
d
σ (E)—an energy-dependent displacement cross section; σ¯ denotes a spectrum-averaged value. Usual unit is barns.
d d
σ (E)—an energy-dependent damage energy cross section; σ¯ denotes a spectrum-averaged value. Usual unit is barns-eV or
de de
barns-keV.
4. Significance and Use
4.1 A characteristic advantage of charged-particle irradiation experiments is precise, individual, control over most of the
important irradiation conditions such as dose, dose rate, temperature, and quantity of gases present. Additional attributes are the
lack of induced radioactivation of specimens and, in general, a substantial compression of irradiation time, from years to hours,
to achieve comparable damage as measured in displacements per atom (dpa). An important application of such experiments is the
investigation of radiation effects in not-yet-existing environments, such as fusion reactors.
4.2 The primary shortcoming of ion bombardments stems from the damage rate, or temperature dependences of the
microstructural evolutionary processes in complex alloys, or both. It cannot be assumed that the time scale for damage evolution
can be comparably compressed for all processes by increasing the displacement rate, even with a corresponding shift in irradiation
temperature. In addition, the confinement of damage production to a thin layer just (often ; 1 μm) below the irradiated surface
can present substantial complications. It must be emphasized, therefore, that these experiments and this practice are intended for
research purposes and not for the certification or the qualification of equipment.
4.3 This practice relates to the generation of irradiation-induced changes in the microstructure of metals and alloys using
charged particles. The investigation of mechanical behavior using charged particles is covered in Practice E821.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
´2
E521 − 96 (2009)
5. Apparatus
5.1 Accelerator—The major item is the accelerator, which in size and complexity dwarfs any associated equipment. Therefore,
it is most likely that irradiations will be performed at a limited number of sites where accelerators are available (a 1-MeV electron
microscope may also be considered an accelerator).
5.2 Fixtures for holding specimens during irradiation are generally custom-made as are devices to measure and control particle
energy, particle flux, and specimen temperature. Decisions regarding apparatus are therefore left to individual workers with the
request that accurate data on the performance of their equipment be reported with their results.
6. Composition of Specimen
6.1 An elemental analysis of stock from which specimens are fabricated should be known. The manufacturer’s heat number and
analysis are usually sufficient in the case of commercally produced metals. Additional analysis should be performed after other
steps in the experimental procedure if there is cause to believe that the composition of the specimen may have been altered. It is
desirable that uncertainties in the analyses be stated and that an atomic basis be reported in addition to a weight basis.
7. Preirradiation Heat Treatment of Specimen
7.1 Temperature and time of heat treatments should be well controlled and reported. This applies to intermediate anneals during
fabrication, especially if a metal specimen is to be irradiated in the cold-worked condition, and it also applies to operations where
specimens are bonded to metal holders by diffusion or by brazing. The cooling rate between annealing steps and between the final
annealing temperature and room temperature should also be controlled and reported.
7.2 The environment of the specimen during heat treatment should be reported. This includes description of container, measure
of vacuum, presence of gases (flowing or steady), and the presence of impurity absorbers such as metal sponge. Any discoloration
of specimens following an anneal should be reported.
7.3 High-temperature annealing of metals and alloys from Groups IV, V, and VI frequently results in changes, both positive and
negative, in their interstitial impurity content. Since the impurity content may have a significant influence on void formation, an
analysis of the specimen or of a companion piece prior to irradiation should be performed. Other situations, such as selective
vaporization of alloy constituents during annealing, would also require a final analysis.
7.4 The need for care with regard to alterations in composition is magnified by the nature of the specimens. They are usually
very thin with a high exposed surface-to-volume ratio. Information is obtained from regions whose distance from the surface may
be small relative to atomic diffusion distances.
8. Plastic Deformation of Specimen
8.1 When plastic deformation is a variable in radiation damage, care must be taken in the geometrical measurements used to
compute the degree of deformation. The variations in dimensions of the larger piece from which specimens are cut should be
measured and reported to such a precision that a standard deviation in the degree of plastic deformation can be assigned to the
specimens. A measuring device more accurate and precise than the common hand micrometer will probably be necessary due to
the thinness of specimens commonly irradiated.
8.2 The term cold-worked should not stand alone as a description of state of deformation. Every effort should be made to
characterize completely the deformation. The parameters which should be stated are: (1) deformation process (for example, simple
tension or compression, swaging, rolling, rolling with applied tension); (2) total extent of deformation, expressed in terms of the
principal orthogonal natural strain components (ε , ε , ε ) or the geometric shape changes that will allow the reader to compute
1 2 3
the strains; (3) procedure used to reach the total strain level (for example, number of rolling passes and reductions in each); (4)
strain rate; and (5) deformation temperature, including an estimate of temperature changes caused by adiabatic work.
8.2.1 Many commonly used deformation processes (for example, rolling and swaging) tend to be nonhomogeneous. In such
cases the strain for each pass can be best stated by the dimensions in the principal working directions before and after each pass.
The strain rate can then be specified sufficiently by stating the deformation time of each pass.
9. Preirradiation Metallography of Specimen
9.1 A general examination by light microscopy and transmission-electron microscopy should be performed on the specimen in
the condition in which it will be irradiated. In some cases, this means that the examination should be done on specimens that were
mounted for irradiation and then unmounted without being irradiated. The microstructure should be described in terms of grain
size, phases, precipitates, dislocations, and inclusions.
9.2 A section of a representative specimen cut parallel to the particle beam should be examined by light microscopy. Attention
should be devoted to the microstructure within a distance from the incident surface equal to the range of the particle, as well as
to the flatness of the surface.
´2
E521 − 96 (2009)
10. Surface Condition of Specimen
10.1 The surface of the specimen should be clean and flat. Details of its preparation should be reported. Electropolishing of
metallic specimens is a convenient way of achieving these objectives in a single operation. The possibility that hydrogen is
absorbed by the specimen during electropolishing should be investigated by analyses of polished and nonpolished specimens.
Deviations in the surface form the perfect-planar condition should not exceed, in dimension perpendicular to the plane, 10 % of
the expected particle range in the specimen.
10.2 The specimen may be irradiated in a mechanically polished condition provided damage produced by polishing does not
extend into the region of postirradiation examination.
11. Dimension of Specimen Parallel to Particle Beam
11.1 Specimens without support should be thick enough to resist
...
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