ASTM E3084-17(2022)e1
(Practice)Standard Practice for Characterizing Particle Irradiations of Materials in Terms of Non-Ionizing Energy Loss (NIEL)
Standard Practice for Characterizing Particle Irradiations of Materials in Terms of Non-Ionizing Energy Loss (NIEL)
SIGNIFICANCE AND USE
4.1 A radiation-hardness assurance program requires a methodology for relating radiation-induced changes in materials exposed to a variety of particle species over a wide range of energies, including those encountered in spacecraft and in terrestrial environments as well as those produced by particle accelerators and nuclear fission and fusion reactors.
4.2 A major source of radiation damage in electronic and photonic devices and materials is the displacement of atoms from their normal lattice site. An appropriate exposure parameter for such damage is the damage energy calculated from NIEL by means of Eq 2. Other analogous measures, which may be used to characterize the irradiation history that is relevant to displacement damage, are damage energy per atom or per unit mass (displacement kerma, when the primary particles are neutral), and displacements per atom (dpa). See Terminology E170 for definitions of those quantities.
4.3 Each of the quantities mentioned in the previous paragraph should convey similar information, but in a different format. In each case the value of the derived exposure parameter depends on approximate nuclear, atomic, and lattice models, and on measured or calculated cross sections. If consistent comparisons are to be made of irradiation effects caused by different particle species and energies, it is essential that these approximations be consistently applied.
4.4 No correspondence should be assumed to exist between damage energy as calculated from NIEL and a particular change in a material property or device parameter. Instead, the damage energy should be used as a parameter which describes the exposure. It may be a useful correlation variate, even when different particle species and energies are included. NIEL should not be reported as a measure of damage, however, unless its correlation with a particular damage modality has been demonstrated in that material or device.
4.5 NIEL is a construct that depends on a model of the par...
SCOPE
1.1 This practice describes a procedure for characterizing particle irradiations of materials in terms of non-ionizing energy loss (NIEL). NIEL is used in published literature to characterize both charged and neutral particle irradiations.
1.2 Although the methods described in this practice apply to any particles and target materials for which displacement cross sections are known (see Practice E521), this practice is intended for use in irradiations in which observed damage effects may be correlated with atomic displacements. This is true of some, but not all, radiation effects in electronic and photonic materials.
1.3 Procedures analogous to this one are used for calculation of displacements per atom (dpa) in charged particle irradiations (see Practice E521) or neutron irradiations (see Practice E693).
1.4 Guidance on calculation of dpa from NIEL is provided.
1.5 Procedures related to this one are used for calculation of 1-MeV equivalent neutron fluence in electronic materials (see Practice E722), but in that practice the concept of damage efficiency, based on correlation of observed damage effects, is included.
1.6 Guidance on conversion of NIEL in silicon to monoenergetic neutron fluence in silicon (see Practice E722), and vice versa, is provided.
1.7 The application of this standard requires knowledge of the particle fluence and energy distribution of particles whose interaction leads to displacement damage.
1.8 The correlation of radiation effects data is beyond the scope of this standard. A comprehensive review (1)2 of displacement damage effects in silicon and their correlation with NIEL provides appropriate guidance that is applicable to semiconductor materials and electronic devices.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standa...
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: E3084 − 17 (Reapproved 2022)
Standard Practice for
Characterizing Particle Irradiations of Materials in Terms of
Non-Ionizing Energy Loss (NIEL)
This standard is issued under the fixed designation E3084; 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—A misspelling in Section 5 was editorially corrected in July 2022.
1. Scope displacement damage effects in silicon and their correlation
with NIEL provides appropriate guidance that is applicable to
1.1 This practice describes a procedure for characterizing
semiconductor materials and electronic devices.
particle irradiations of materials in terms of non-ionizing
1.9 This international standard was developed in accor-
energy loss (NIEL). NIEL is used in published literature to
dance with internationally recognized principles on standard-
characterize both charged and neutral particle irradiations.
ization established in the Decision on Principles for the
1.2 Althoughthemethodsdescribedinthispracticeapplyto
Development of International Standards, Guides and Recom-
any particles and target materials for which displacement cross
mendations issued by the World Trade Organization Technical
sections are known (see Practice E521), this practice is
Barriers to Trade (TBT) Committee.
intended for use in irradiations in which observed damage
effects may be correlated with atomic displacements. This is
2. Referenced Documents
true of some, but not all, radiation effects in electronic and
2.1 ASTM Standards:
photonic materials.
E170 Terminology Relating to Radiation Measurements and
1.3 Procedures analogous to this one are used for calcula-
Dosimetry
tion of displacements per atom (dpa) in charged particle
E521 Practice for Investigating the Effects of Neutron Ra-
irradiations (see Practice E521) or neutron irradiations (see
diation Damage Using Charged-Particle Irradiation
Practice E693).
E693 Practice for Characterizing Neutron Exposures in Iron
1.4 Guidance on calculation of dpa from NIEL is provided. and Low Alloy Steels in Terms of Displacements Per
Atom (DPA)
1.5 Procedures related to this one are used for calculation of
E722 PracticeforCharacterizingNeutronFluenceSpectrain
1-MeV equivalent neutron fluence in electronic materials (see
Terms of an Equivalent Monoenergetic Neutron Fluence
Practice E722), but in that practice the concept of damage
for Radiation-Hardness Testing of Electronics
efficiency, based on correlation of observed damage effects, is
included.
3. Terminology
1.6 Guidance on conversion of NIEL in silicon to monoen-
3.1 Definitions of some terms used in this practice can be
ergetic neutron fluence in silicon (see Practice E722), and vice
found in Terminology E170.
versa, is provided.
3.2 Definitions:
1.7 The application of this standard requires knowledge of
3.2.1 tracked particles—those particles whose position-
the particle fluence and energy distribution of particles whose
dependent fluence spectra are calculated in a particle transport
interaction leads to displacement damage.
calculation for a specific target geometry.
1.8 The correlation of radiation effects data is beyond the
3.2.1.1 Discussion—In calculating displacement damage
scope of this standard. A comprehensive review (1) of
energy and NIEL, the tracked particles should include
neutrons, photons, protons, and ions up toZ=2, unless their
contributions are known to be negligible. Heavier ions may
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
also be tracked in some Monte Carlo codes. Except in the case
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 July 1, 2022. Published July 2022. Originally approved
in 2017. Last previous edition approved in 2017 as E3084 – 17. DOI: 10.1520/ For referenced ASTM standards, visit the ASTM website, www.astm.org, or
E3084-17R22E01. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3084 − 17 (2022)
of neutrons, particles below a specified minimum energy are with the tracked-particle fluence spectrum over all energies,
not tracked, and are treated as non-tracked particles. and summing over all species of tracked particle:
`
3.2.2 tracked-particle fluence spectrum, Φ (E)—the fluence
p
¯
dε ⁄ dm 5Σ NIEL E Φ E dE (2)
* ~ ! ~ !
d p p
spectrum of particles, of species p and at particle energy E, that
p
are tracked in a particle transport calculation. For each species
3.2.4.5 Discussion—The 1 MeV equivalent neutron fluence
of tracked particle other than neutrons there is a specified –2
(cm ) in silicon may be calculated by dividing the damage
minimum energy. Particles at lower energy are non-tracked
energy per unit mass (MeV/g) in Eq 2 by 2.037 MeV cm /g
particles.
(see 3.2.4.1).
3.2.4.6 Discussion—The dpa may be calculated from the
3.2.3 secondary particles—those particles produced in a
damage energy per unit mass by multiplying by the average
material by interaction with the tracked particles. Secondary
atomic mass of the target and by β/2T , where β is an atomic
particles may include tracked particles and non-tracked par-
d
scattering correction factor equal to 0.8 and T is the displace-
ticles.
d
ment threshold. This approximation to the Norgett, Robinson,
3.2.4 non-ionizing energy loss, NIEL (E)—the quotient of
p
and Torrens (3) model is consistent with the method recom-
dɛ¯ by Φ (E).dE.dm, where Φ (E)dE is the tracked-particle
d p p
mended in Practice E521 (14.5.2.1).
fluence in the energy interval E to E+dE of particle species p
3.2.4.7 Discussion—In cases where secondary particle equi-
in a volume element containing material of mass dm, and dɛ¯
d
librium does not apply due to inhomogeneities in the target
is that part of the mean energy imparted to matter by the
material, the damage energy that can be calculated from NIEL
tracked particle radiation which produces atomic displace-
values is not necessarily equivalent to the local value of the
ments and lattice phonons (that is, excluding the part that
absorbed dose that leads to displacements. The scale of the
produces ionization and excitations of electrons).
relevant inhomogeneities depends on the energies and actual
¯
NIEL E 5 dε ⁄ Φ E dEdm (1) ranges of the non-tracked secondary particles. Detailed Monte
~ ! ~ !
p d p
Carlo modeling in which tracked particles include all those
2 –1 2 –1
Unit: MeV·m ·kg . (also used are keV·cm ·g , and
secondary particles whose range is comparable with or greater
2 –1
MeV·cm ·g )
than the scale of the material inhomogeneity in the target
3.2.4.1 Discussion—For silicon, using the atomic mass
geometry is necessary. Suitable codes include MCNP6, Geant,
28.086 g/mol, a displacement kerma cross section 100
and SRIM (4-9).
MeV·mbarn is equivalent to 2.144 MeV·cm /g (2). Micro-
scopic displacement kerma cross sections (see Practice E722)
4. Significance and Use
having units with dimensions equal to the product of energy
4.1 A radiation-hardness assurance program requires a
and area (for example, MeV·mbarn) are sometimes used to
methodology for relating radiation-induced changes in materi-
apply to single target atoms, and may be thought of as the
als exposed to a variety of particle species over a wide range of
microscopic version of NIEL. For 1-MeV neutrons the refer-
energies, including those encountered in spacecraft and in
ence value of the displacement damage function in silicon is
terrestrial environments as well as those produced by particle
definedinPracticeE722asequalto95MeV·mbarn,equivalent
accelerators and nuclear fission and fusion reactors.
2 2 –1
to a NIEL value of 2.037 MeV·cm /g (0.2037 Mev·m ·kg ).
4.2 A major source of radiation damage in electronic and
3.2.4.2 Discussion—In Eq 1, NIEL (E) is to be interpreted
p
photonic devices and materials is the displacement of atoms
as a function dependent on the particle energy, on the species
from their normal lattice site. An appropriate exposure param-
of particle, and on the material in which the particle fluence is
eter for such damage is the damage energy calculated from
present. Its use requires knowledge of NIEL for all energies
NIELbymeansofEq2.Otheranalogousmeasures,whichmay
and tracked-particle species that contribute significantly to the
be used to characterize the irradiation history that is relevant to
total displacement damage energy in a given material.
displacement damage, are damage energy per atom or per unit
3.2.4.3 Discussion—In the definition, Eq 1, the volume
mass (displacement kerma, when the primary particles are
element in which the tracked-particle fluence Φ is present
p
neutral), and displacements per atom (dpa). SeeTerminology
does not necessarily contain all of the atomic displacements
E170 for definitions of those quantities.
produced by the energy transferred, dɛ¯ . The quantity is
d
4.3 Each of the quantities mentioned in the previous para-
calculated as if the extended volume, dependent on the particle
graph should convey similar information, but in a different
energy, in which displacements occur is homogeneous and of
format. In each case the value of the derived exposure
the same composition as the volume element in which the
parameter depends on approximate nuclear, atomic, and lattice
tracked-particle fluence is present. This assumption is justified
models, and on measured or calculated cross sections. If
in cases in which secondary particle equilibrium applies for the
consistent comparisons are to be made of irradiation effects
non-tracked particles: the number and energy distribution of
caused by different particle species and energies, it is essential
secondary particles entering a volume element is the same as
that these approximations be consistently applied.
forthoseleavingthatelement.Seetheanalogousdescriptionof
“charged particle equilibrium” in the definition of kerma,
4.4 No correspondence should be assumed to exist between
Terminology E170.
damage energy as calculated from NIEL and a particular
3.2.4.4 Discussion—Damageenergyperunitmass, dɛ¯ /dm, change in a material property or device parameter. Instead, the
d
iscalculatedfromNIELbyintegratingtheproductoftheNIEL damage energy should be used as a parameter which describes
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E3084 − 17 (2022)
the exposure. It may be a useful correlation variate, even when 5.3 Most authors who have used formulae analogous to Eq
different particle species and energies are included. NIEL 3 have followed the precedent of Burke (11), but excluding
should not be reported as a measure of damage, however, light ions with masses up to and including He-4 from the
unless its correlation with a particular damage modality has secondary particles that contribute to NIEL. This is equivalent
been demonstrated in that material or device. to treating such particles as tracked particles whose contribu-
tions to displacement were ignored.
4.5 NIEL is a construct that depends on a model of the
particle interaction processes in a material, as well as the cross
5.4 Radiation-induced damage to the lattice of solid mate-
section for each type of interaction. It is essential, when using
rials arises from elastic collisions and nuclear reactions result-
NIEL as a correlation parameter, to ensure that consistent
ing in high energy recoils. These cause ionization and excita-
modeling parameters and nuclear data are used to calculate the tionoftheatomsintheirradiatedmaterialaswellaselasticand
NIEL value for each irradiation.
inelastic scattering which produce displacement of the atoms
from their sites in the lattice. Ionization is a transient effect in
4.6 Damage energy deposited in materials can be calculated
many semiconductors and does not contribute to permanent
directly, without the use of NIEL, using the Monte Carlo codes
damage in, for example, bulk silicon (2). Elastic collisions and
mentioned in 3.2.4.7, if all the particles involved in atomic
inelasticreactionscangeneratepermanentstablelatticedefects
displacement are tracked. The utility of the NIEL concept
via what are called displacement cascades. Cascade dynamics
arises in cases where some particles, especially recoiling heavy
are best described by molecular dynamics simulations (18)
ions, do not need to be tracked. In the NIEL representation,
although energy partitioning can also be obtained from Monte
these are treated instead by means of infinite homogeneous
Carlo simulations (4-9) and other transport calculations.
mediumsolutionsofthetypeoriginatedbyLindhardetal. (10).
5.5 The partition of the secondary particle energy T be-
k
5. Calculation of NIEL
tween electronic excitation and atomic displacements is re-
5.1 The method of calculating NIEL used in this practice is
flected in the partition function L(T ), sometimes called the
k
based on that originally proposed for proton irradiation of
damage efficiency. Various approximations to the partition
silicon by Burke (11). Similar NIEL calculations and compari-
function have been used, based on the Lindhard screened
sonstoexperimenthavesincebeendoneforotherparticlesand
potentialscatteringtheory(LSS) (10),usingtheThomas-Fermi
other targets (12-17).
model.An approximation based on the LSS model is given by
the Robinson fit (19), used also in the NRT model (3) for
5.2 The basic formula for the calculation of NIEL is:
calculating dpa:
`
dσ E,T
~ !
pik k
NIEL ~E! 5ΣN Σ T L~T !dT (3)
*
p i k k k
dT
i k L~T ! 5 (4)
k
0 k 1⁄6 3⁄4
11F ~3.4008 ε 1 0.40244 ε 1 ε!
L
T
k
where:
where ε5 , with
E
L
N=w,N /A = thenumberoftargetatomsofisotope iper
i i av i
2⁄3 2⁄3 1⁄2
E 5 30.724 Z Z ~Z 1 Z ! ~A 1 A !⁄A , and (5)
unit mass, L k L k L k L L
2⁄3 1⁄2 3⁄2
w = the weight fraction of isotope i in the
i 0.0793Z Z ~A 1 A !
k L k L
F (6)
L 2⁄3 2⁄3 3⁄4 3⁄2 1⁄2
target,
Z 1 Z ! A A
~
k L k L
N = is Avogadro’s number/mole,
A and Z are mass numbers and atomic numbers and the sub-
Av
A = the molar mass for isotope i, scripts L and k stand for lattice atom and recoil particle, re-
i
T = the energy of a non-t
...
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