1、Dosimetry for exposures to cosmic radiation in civilian aircraftPart 2: Characterization of instrument responseBS EN ISO 20785-2:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 20785-2 October 2017 ICS 49.0
2、20; 13.280 English Version Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 2: Characterization of instrument response (ISO 20785-2:2011) Dosimtrie de lexposition au rayonnement cosmique dans laviation civile - Partie 2: Caractrisation de la rponse des instruments (ISO 20785-2
3、:2011) This European Standard was approved by CEN on 13 September 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliograp
4、hical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibili
5、ty of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic o
6、f Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NOR
7、MALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 20785-2:2017 ENational forewordThis British Standard is the UK impl
8、ementation of EN ISO 20785-2:2017. It is identical to ISO 20785-2:2011. It supersedes BS ISO 20785-2:2011, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee NCE/2, Radiation protection and measurement.A list of organizations represented on this committee
9、 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 96934 8ICS 13.280; 49.
10、020Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2011.Amendments/corrigenda issued since publicationDate Text affected31 December 2017 This corrigendum
11、 renumbers BS ISO 20785-2:2011 as BS EN ISO 20785-2:2017BRITISH STANDARDBS EN ISO 20785-2:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 20785-2 October 2017 ICS 49.020; 13.280 English Version Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 2: Characterization o
12、f instrument response (ISO 20785-2:2011) Dosimtrie de lexposition au rayonnement cosmique dans laviation civile - Partie 2: Caractrisation de la rponse des instruments (ISO 20785-2:2011) This European Standard was approved by CEN on 13 September 2017. CEN members are bound to comply with the CEN/CEN
13、ELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre
14、or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the of
15、ficial versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherland
16、s, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All
17、rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 20785-2:2017 EBS EN ISO 20785-2:2017EN ISO 20785-2:2017 (E) 3 European foreword The text of ISO 20785-2:2011 has been prepared by Technical Committee ISO/TC 85 “Nuclear energy, nuclear te
18、chnologies, and radiological protection” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 20785-2:2017 by Technical Committee CEN/TC 430 “Nuclear energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR. This Eu
19、ropean Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2018, and conflicting national standards shall be withdrawn at the latest by April 2018. Attention is drawn to the possibility that some of the eleme
20、nts of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard:
21、 Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia,
22、 Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 20785-2:2011 has been approved by CEN as EN ISO 20785-2:2017 without any modification. ISO 20785-2:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative refe
23、rences1 3 Terms and definitions .2 3.1 General terms 2 3.2 Terms related to quantities and units .7 3.3 Terms related to the atmospheric radiation field.11 4 General considerations.12 4.1 The cosmic radiation field in the atmosphere12 4.2 General considerations for the dosimetry of the cosmic radiat
24、ion field in aircraft and requirements for the characterization of instrument response .14 4.3 General considerations for measurements at aviation altitudes .15 5 Calibration fields and procedures .16 5.1 General considerations.16 5.2 Characterization of an instrument .18 5.3 Instrument-related soft
25、ware .21 6 Uncertainties22 7 Remarks on performance tests22 Annex A (informative) Representative particle fluence energy distributions for the cosmic radiation field at flight altitudes for solar minimum and maximum conditions and for minimum and maximum vertical cut-off rigidity 23 Annex B (informa
26、tive) Radiation fields recommended for use in calibrations.25 Annex C (informative) Comparison measurements 29 Annex D (informative) Charged-particle irradiation facilities31 Bibliography32 BS EN ISO 20785-2:2017ISO 20785-2:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introducti
27、on.v 1 Scope1 2 Normative references1 3 Terms and definitions .2 3.1 General terms 2 3.2 Terms related to quantities and units .7 3.3 Terms related to the atmospheric radiation field.11 4 General considerations.12 4.1 The cosmic radiation field in the atmosphere12 4.2 General considerations for the
28、dosimetry of the cosmic radiation field in aircraft and requirements for the characterization of instrument response .14 4.3 General considerations for measurements at aviation altitudes .15 5 Calibration fields and procedures .16 5.1 General considerations.16 5.2 Characterization of an instrument .
29、18 5.3 Instrument-related software .21 6 Uncertainties22 7 Remarks on performance tests22 Annex A (informative) Representative particle fluence energy distributions for the cosmic radiation field at flight altitudes for solar minimum and maximum conditions and for minimum and maximum vertical cut-of
30、f rigidity 23 Annex B (informative) Radiation fields recommended for use in calibrations.25 Annex C (informative) Comparison measurements 29 Annex D (informative) Charged-particle irradiation facilities31 Bibliography32 BS EN ISO 20785-2:2017ISO 20785-2:2011(E) iv ISO 2011 All rights reservedForewor
31、d ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (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 technica
32、l 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 ele
33、ctrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to th
34、e member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for ide
35、ntifying any or all such patent rights. ISO 20785-2 was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies, and radiological protection, Subcommittee SC 2, Radiological protection. ISO 20785 consists of the following parts, under the general title Dosimetry for exposures
36、 to cosmic radiation in civilian aircraft: Part 1: Conceptual basis for measurements Part 2: Characterization of instrument response A Part 3 dealing with measurements at aviation altitudes is in preparation. BS EN ISO 20785-2:2017ISO 20785-2:2011(E) ISO 2011 All rights reserved vIntroduction Aircra
37、ft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 601, confirmed by
38、Publication 1032, the European Union (EU) introduced a revised Basic Safety Standards Directive3which included exposure to natural sources of ionizing radiation, including cosmic radiation, as occupational exposure. The Directive requires account to be taken of the exposure of aircraft crew liable t
39、o receive more than 1 mSv per year. It then identifies the following four protection measures: (i) to assess the exposure of the crew concerned; (ii) to take into account the assessed exposure when organizing working schedules with a view to reducing the doses of highly exposed crew; (iii) to inform
40、 the workers concerned of the health risks their work involves; and (iv) to apply the same special protection during pregnancy to female crew in respect of the “child to be born” as to other female workers. The EU Council Directive has already been incorporated into laws and regulations of EU member
41、 states and is being included in the aviation safety standards and procedures of the Joint Aviation Authorities and the European Air Safety Agency. Other countries, such as Canada and Japan, have issued advisories to their airline industries to manage aircraft crew exposure. For regulatory and legis
42、lative purposes, the radiation protection quantities of interest are equivalent dose (to the foetus) and effective dose. The cosmic radiation exposure of the body is essentially uniform, and the maternal abdomen provides no effective shielding to the foetus. As a result, the magnitude of equivalent
43、dose to the foetus can be put equal to that of the effective dose received by the mother. Doses on board aircraft are generally predictable, and events comparable to unplanned exposure in other radiological workplaces cannot normally occur (with the rare exceptions of extremely intense and energetic
44、 solar particle events). Personal dosemeters for routine use are not considered necessary. The preferred approach for the assessment of doses of aircraft crew, where necessary, is to calculate directly the effective dose per unit time, as a function of geographic location, altitude and solar cycle p
45、hase, and to combine these values with flight and staff roster information to obtain estimates of effective doses for individuals. This approach is supported by guidance from the European Commission and the ICRP in Publication 754. The role of calculations in this procedure is unique in routine radi
46、ation protection, and it is widely accepted that the calculated doses should be validated by measurement5. Effective dose is not directly measurable. The operational quantity of interest is the ambient dose equivalent, H*(10). In order to validate the assessed doses obtained in terms of effective do
47、se, calculations can be made of ambient dose equivalent rates or route doses in terms of ambient dose equivalent, and values of this quantity determined by measurements traceable to national standards. The validation of calculations of ambient dose equivalent for a particular calculation method may
48、be taken as a validation of the calculation of effective dose by the same computer code, but this step in the process might need to be confirmed. The alternative is to establish, a priori, that the operational quantity ambient dose equivalent is a good estimator of effective dose and equivalent dose
49、 to the foetus for the radiation fields being considered, in the same way that the use of the operational quantity personal dose equivalent is justified for the estimation of effective dose for radiation workers. The radiation field in aircraft at altitude is complex, with many types of ionizing radiation present, with energies ranging up to many GeV. The determination of ambient dose equivalent for such a complex radiation field is difficult. In many cases, the methods used for the determination of ambient dose equivalent in aircraf
