IEC PAS 62396-2:2007

IEC/PAS 62396-2
Edition 1.0 2007-09
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
Process management for avionics – Atmospheric radiation effects –
Part 2: Guidelines for single event effects testing for avionics systems

IEC/PAS 62396-2:2007(E)
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
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,

please contact the address below or your local IEC member National Committee for further information.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC/PAS 62396-2
Edition 1.0 2007-09
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
Process management for avionics – Atmospheric radiation effects –
Part 2: Guidelines for single event effects testing for avionics systems

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
T
ICS 03.100.50; 31.020; 49.060 ISBN 2-8318-9202-3

– 2 – PAS 62396-2 © IEC:2007(E)

CONTENTS
FOREWORD.3

1 General .5

1.1 Use of existing SEE data.5

1.2 Deciding to perform dedicated SEE tests.6

2 Availability of existing SEE data for avionics applications .6
2.1 Types of existing SEE data that may be used.6
2.1.1 Sources of data, proprietary versus published data .7
2.1.2 Data based on the use of different sources.8
2.1.3 Ground level versus avionics applications .11
2.2 Sources of existing data .12
3 Considerations for SEE Testing .13
3.1 Selection of hardware to be tested .14
3.2 Selection of test method.14
3.3 Selection of facility providing energetic particles .15
3.3.1 Spallation neutron source .15
3.3.2 Monoenergetic and quasi-monoenergetic beam sources.16
3.3.3 Thermal neutron sources .17
4 Converting test results to avionics SEE rates .17
4.1 Use of spallation neutron source .17
4.2 Use of SEU cross section curve over energy .18

Bibliography.21

Figure 1 – Comparison of Los Alamos and TRIUMF neutron spectra with terrestrial
neutron spectrum.9
Figure 2 – Variation of high energy neutron SEU cross section per bit as a function of
device feature size.10
Figure 3 — Comparison of mono-energetic SEU cross sections with Weibull and
Piece-Wise Linear Fits .20

Table 1 – Sources of existing data .13

PAS 62396-2 © IEC:2007(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
PROCESS MANAGEMENT FOR AVIONICS –

ATMOSPHERIC RADIATION EFFECTS –

Part 2: Guidelines for single event effects testing

for avionics systems
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
A PAS is a technical specification not fulfilling the requirements for a standard but made

available to the public.
IEC-PAS 62396-2 has been processed by IEC technical committee 107: Process management
for avionics.
The text of this PAS is based on the This PAS was approved for publication
following document: by the P-members of the committee
concerned as indicated in the following
document:
Draft PAS Report on voting
107/57/NP 107/69/RVN
Following publication of this PAS, which is a pre-standard publication, the technical committee
or subcommittee concerned will transform it into an International Standard.

– 4 – PAS 62396-2 © IEC:2007(E)

This PAS shall remain valid for an initial maximum period of three years starting from 2007-09.

The validity may be extended for a single three-year period, following which it shall be revised

to become another type of normative document or shall be withdrawn.

IEC/PAS 62396 consists of the following parts, under the general title Process management

for avionics – Atmospheric radiation effects:

• Part 2: Guidelines for single event effects testing for avionics systems

• Part 3: Optimising system design to accommodate the Single Event Effects (SEE) of

atmospheric radiation
• Part 4: Guidelines for designing with high voltage aircraft electronics and potential
single event effects
• Part 5: Guidelines for assessing thermal neutron fluxes and effects in avionics
systems
PAS 62396-2 © IEC:2007(E) – 5 –

PROCESS MANAGEMENT FOR AVIONICS –

ATMOSPHERIC RADIATION EFFECTS –

Part 2: Guidelines for single event effects testing

for avionics systems
1 General
The purpose of this PAS is to provide guidance related to the testing of microelectronic

devices for purposes of measuring their susceptibility to single event effects (SEE) induced by
the atmospheric neutrons. Since the testing can be performed in a number of different ways,
using different kinds of radiation sources, it also shows how the test data can be used to
estimate the SEE rate of devices and boards due to the atmospheric neutrons in the
atmosphere at aircraft altitudes.
The type of SEE data available can be viewed from many different perspectives. As indicated,
the SEE testing can be performed using a variety of radiation sources, all of which can induce
single event effects in ICs. In addition, many tests are performed on individual devices, but
some tests expose an entire single board computer to radiation fields that can induce SEE
effects. However, a key discriminator is deciding on whether existing SEE data is available
that may be used, or whether there really is no existing data and therefore, a SEE test on the
device or board of interest has to be carried out.
1.1 Use of existing SEE data
The simplest solution is to find previous SEE data on a specific IC device. This is not nearly
as simple as it appears. First, the largest interest lies in SEE data that is directly usable for
purposes of estimating the SEE rate in avionics. Thus, SEE tests that have been carried out
on devices using heavy ions, data which is directly applicable for space missions, is data that
is not directly applicable for avionics purposes. This heavy ion SEE data can be used to
calculate SEE data from high energy neutrons and protons by utilizing a number of different
calculation methods, but this requires the active involvement of a radiation effects expert in
the process. Therefore, heavy ion SEE data should not be used for application to the
atmospheric neutron environment, except by scientists and engineers who have extensive
experience in using this kind of data. For that reason, unless otherwise stated explicitly, when
SEE data is discussed in the remainder of this PAS, it refers only to single event testing using
a neutron or proton source, not to the results from testing with heavy ions.
If SEE data on a device of interest is found from SEE tests using high energy neutrons or
protons, it will still require expertise regarding how the data is to be utilized in order to
calculate a SEE rate at aircraft altitudes. Data obtained by IC vendors for their standard
application to ground level systems are often expressed in totally different units, FIT units,
where one FIT is one error in 10 device hours, which is taken to apply at ground level.
IC devices are constantly changing. In some cases, devices which had been tested, become
obsolete and are replaced by new devices which have not been tested. The fact that a device
is made by the same IC vendor and is of the same type as the one it replaced does not mean
that the SEE data measured in the first device applies directly to the newer device. In some
cases, small changes in the IC design or manufacturing process can have a large effect in
altering the SEE response, but in other cases, the effect on the SEE response may be
minimal.
A continuing problem with the existing SEE data is that there is no single data base
containing all of the neutron or proton SEE data. Instead, portions of this kind of SEE data
can
...