1、BSI Standards Publication PD ISO/TR 18147:2014 Space environment (natural and artificial) Method of the solar energetic protons fluences and peak fluxes determinationPD ISO/TR 18147:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 18147:2014. The U
2、K participation in its preparation was entrusted to Technical Committee ACE/68/-/4, Space systems and operations - Space environment (natural and artificial). A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to inclu
3、de all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 83602 2 ICS 49.140 Compliance with a British Standard cannot confer immunity from legal obligations. This P
4、ublished Document was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014. Amendments issued since publication Date Text affectedPD ISO/TR 18147:2014 ISO 2014 Space environment (natural and artificial) Method of the solar energetic protons fluences and p
5、eak fluxes determination Environnement spatial (naturel et artificiel) Mthode des fluences de protons nergtiques solaires et dtermination des flux de pic TECHNICAL REPORT ISO/TR 18147 First edition 2014-04-15 Reference number ISO/TR 18147:2014(E)PD ISO/TR 18147:2014ISO/TR 18147:2014(E)ii ISO 2014 Al
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7、ut prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in
8、SwitzerlandPD ISO/TR 18147:2014ISO/TR 18147:2014(E) ISO 2014 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Definitions, notations, and abbreviations 1 3 Main principles of the method . 2 4 Calculation technique 3 5 Base tables 4 Annex A (informative) Main methodical principles . 8
9、Annex B (informative) Comparing model and experimental data .17 Bibliography .22PD ISO/TR 18147:2014ISO/TR 18147:2014(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International S
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15、ence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations.iv ISO 2014 All rights reservedPD IS
16、O/TR 18147:2014TECHNICAL REPORT ISO/TR 18147:2014(E) Space environment (natural and artificial) Method of the solar energetic protons fluences and peak fluxes determination 1 Scope This Technical Report is intended for calculating the probability for solar energetic particle (SEP) to have an impact
17、on materials, hardware, and biological objects. This Technical Report establishes the differential energy spectra for the (0,1/10 3 ) MeV SEP fluences and/or peak fluxes in the near-earth space, beyond the earth magnetosphere during the missions any duration under varying solar activity. If addition
18、al prepositions are used, the method establishes the basic fluences and peak fluxes for their determination throughout the heliosphere. When the effect of the particle penetration into the magnetosphere is taken into account (see ISO/AWI 17520, Cosmic ray and solar energetic particle penetration ins
19、ide the magnetosphere: Determination of the vertical cutoff values, draft standard), the method establishes the basic fluences and peak fluxes for their determination on the near-earth spacecraft and manned station orbits. Because the occurrence of SEP is a process a probabilistic nature, fluences a
20、nd peak fluxes calculation relate to the different levels of probability. The method is intended for specialists engaged in determination of radiation conditions in space. 2 Definitions, notations, and abbreviations Term Notation Abbreviation Definition Solar energetic particles (or solar cosmic ray
21、s) SEP High-energy (4 MeV/nucl) charged particle of solar origin. Mission duration T Calendar time period for the SEP peak flux or fluence is model calculated (months). Wolf (sunspot) number W W = k(10g+f ), where g is sunspot group number; f is the total sunspot number on the visible solar disc. k
22、is the coefficient adjusting various obser- vation conditions. Solar activity (SA) level 13-month smoothed month sunspot number or predicted by NOAA month sunspot number. Solar activity condition The sum of the smoothed month sunspot num- bers during the space mission Mission parameter n The paramet
23、er of the model, relative deter- mined as the hypothetic mean number of SEP events with the fluences F 30 10 5cm 2protons with energy 30 MeV expected during the mis- sions duration. Particle energy E Particle energy (MeV/nucleon). Particle fluence F The total (time-integrated) number of particles in
24、 given space mission that traverse a unit area from all directions from solid angle 4 (parti- cle/cm 2 ). ISO 2014 All rights reserved 1PD ISO/TR 18147:2014ISO/TR 18147:2014(E) Term Notation Abbreviation Definition Differential proton fluence energy spectrum dF/dE F(E) Differential particle fluence
25、energy (E) dis- tribution during the space mission particle/ (cm 2 MeV). Integral particle fluence energy spectrum F(E) F E Integral particle fluence energy (E) distribution (at E above a given level) during the space mis- sion (particle/cm 2 ). Particle peak flux f The time when a maximum number of
26、 particles traverse a unit area during the space mission, normally to a given observation, direction in unit time through unit solid angle proton/ (cm 2 srs). NOTE The fluxes of particles with different energy reach maximum values at different times during the SEP event. Differential particle peak f
27、lux energy spectrum df/dE f(E) Differential particle peak flux energy (E) dis- tribution during the space mission particle/ (cm 2 srsMeV). Integral proton peak flux energy spectrum f(E) f E Integral particle peak flux energy (E) distribu- tion during the space mission (or in a set of SEP events) par
28、ticle/(cm 2 srs). SEP fluences and/or peak fluxes occurrence probability P Probability The probability the given fluences and/or fluxes should be exceeded. Small fluxes (fluences or peak f luxes) S Small Fluxes, sizes that exceed probability 0,9, or fluxes occurred at the 0,1 confidence level. Mean
29、fluxes (fluences or peak f luxes) M Mean Fluxes, with probability 0,5 (50/50 case), or at the 0,5 confidence level. Large fluxes (fluences or peak f luxes) L Large Fluxes, sizes that exceed probability 0,1 or occurred at the 0,9 confidence level. Extremal fluxes (fluences or peak fluxes) E Extremal
30、Fluxes, sizes that exceed probability 0,01 or occurred above the 0,99 confidence level. Worst case fluxes (fluences or peak fluxes) W Worst case Fluxes, sizes that exceed probability 0,001 or occurred above the 0,999 confidence level. 3 Main principles of the method 3.1 The method establishes the si
31、zes of the SEP fluences and/or peak fluxes, which are expected with probability P, to get exceeded within a time interval T at a given solar activity conditions. 3.2 Angular distribution of SEP fluxes beyond the earths magnetosphere is taken to be isotropic. 3.3 The solar activity condition is descr
32、ibed as sum of smoothed mean (or predicted) month sunspot (Wolf) numbers 1where m is the number of months with solar activity, , each during mission duration T. 3.4 The mission parameter, n, is determined to be equal as: (1) The value /2 is the mean SEP event (with the fluence, F(E 30 MeV) 10 6proto
33、ns/cm 2 ) number in the considered period.2 ISO 2014 All rights reservedPD ISO/TR 18147:2014ISO/TR 18147:2014(E) 3.5 The solar high energy protons (E 30 MeV) distribution function by integral fluences is described as: (2) where the parameters are C = 28,7, = 0,32, and = 8,10 9 . 3.6 The differential
34、 energy spectra of the particle fluences (F) and/or peak fluxes (f) (referred to henceforth as energy spectra of ) for predicted missions are power-law functions of proton energy, E. (3) where E is the protons kinetic energy in MeV. In case of proton fluxes, the following spectral parameters are tak
35、en: a) E k , the centre of the region in which the energy spectra of the broken off (the effect of the knee). b) DE k , the energy region from E min= E k /DE kto E max= E k DE k , wherein the spectral index is changing from 1to 2 . c) D, differential fluence (or peak flux) at E k . d) At E E k DE k
36、, spectral index is proposed to be 2 . f) In case of E min E E max , is proposed to change as: S (4) where Finally, the differential energy spectra Formula (3) in range (0,1/10 3 ) MeV are described by four parameters (1, 3, 4, 5). Therefore, the parameter DE kis supposed to be constant and equal to
37、 1,37. 4 Calculation technique 4.1 The present model includes the specifications of the differential energy spectra parameters for fluences and peak fluxes for the most frequently used integral probability sequence P = 0,9 (small), 0,75, 0,5 (mean), 0,25, 0,1 (large), 0,01 (extreme), and 0,001 (wors
38、t case). For the sequence of the mission parameters = 1, 2, 4, 8, 16, 32, 64, 128, 256, and 512 are used. The parameters, n = 1/2, describe the annual missions at the deep SA minimum; parameters, n = 8, 16, and 32, describe the annual missions in case of mean sunspot numbers W = 50, 100, and 200 acc
39、ordingly; parameter, n = 128, describe the conditions at the full solar cycle (like 19, 20, 21, 22, and 23 cycles) mission period. In the case of approximation methods used, energy spectra for all possible mission duration at all possible solar active conditions can be described in more detail. 4.2
40、The standard method tabulates the parameters of differential spectra for fluences and peak fluxes. E k , D, 1 , and 2for model parameters P (probability) and (mission parameter eq. mean number of SEP events). 4.3 The particle fluence and/or peak flux calculations involve: ISO 2014 All rights reserve
41、d 3PD ISO/TR 18147:2014ISO/TR 18147:2014(E) 4.3.1 Calculation of the mission parameter, , by Formula (1). In case of future missions, use the predicted sunspot number data from:or in accordance with the data of high activity SA cycle 19 (years 1954-1964) from:4.3.2 Establish the probability (confide
42、nce) level needed. 4.3.3 Use the tabulated parameters data or calculation of four parameters using interpolation of the tabulated data (if needed). In case of parameter D for the interpolation, the logarithm values of D should be used. 4.4 Calculate the differential energy spectrum for needed values
43、, , and P, using Formula (3) and Formula (4). 4.5 In case the integral proton energy spectra are to be calculated, use Formula (5): (5) NOTE As the present model, the tabulated parameters, but not figures, are established. The figures, presented in Annexes, serve only as illustrations. 5 Base tables
44、 Table 1 The coefficients of the proton fluence spectrum log, D(/ P) /P 0,9 0,75 0,5 0.,5 0,1 0,01 0,001 1 - - 6,041 7, 241 7,991 8,732 9,442 2 - 6,076 7,041 7,775 8,253 8,983 9,600 4 6,378 6,972 7, 870 8,173 8,571 9,236 9,732 8 7, 324 7, 874 8,220 8,520 8,820 9,442 9,860 16 8,140 8,380 8,630 8,859
45、9,010 9,647 9,982 32 8,640 8,820 8,986 9,137 9,367 9,810 10,190 64 9,037 9,176 9,322 9,465 9,671 9,978 10,210 128 9,441 9,556 9,658 9,799 9,942 1,127 10,320 256 9,829 9,899 9,989 10,104 10,199 10,360 10,440 512 10,143 10,233 10,303 10,405 10,479 10,577 10,6134 ISO 2014 All rights reservedPD ISO/TR 1
46、8147:2014ISO/TR 18147:2014(E) Table 2 The knee energy (MeV) of the proton fluence spectrum, Ek(/ P) /P 0,9 0,75 0,5 0,25 0,1 0,01 0,001 1 - - 9,715 8,279 9,636 18,240 16,067 2 - 9,809 8,700 9,900 12,732 17, 540 15,756 4 9,900 9,500 8,500 11,689 14,380 16,720 15,182 8 9,545 8,946 9,500 13,250 16,500
47、16,092 14,518 16 7,983 8,500 12,100 14,454 16,800 15,449 14,455 32 9,429 12,087 13,321 15,200 15,970 14,782 14,373 64 12,123 12,898 13,700 14,992 14,645 14,562 14,580 128 13,185 13,424 14,179 14,397 14,276 14,468 14,800 256 13,499 13,745 14,083 14,087 14,024 13,984 14,918 512 14,384 13,992 14,152 13
48、,698 13,596 13,672 14,757 Table 3 The index 1 of the proton fluence spectrum, 1(/ P) /P 0,9 0,75 0,5 0,25 0,1 0,01 0,001 1 - - 1,681 1,619 1,464 1,375 1,398 2 - 1,677 1,671 1,538 1,420 1,375 1,418 4 1,710 1,640 1,530 1,461 1,400 1,380 1,440 8 1,674 1,583 1,490 1,430 1,392 1,390 1,460 16 1,549 1,472 1,449 1,400 1,390 1,400 1,480 32 1,480 1,450 1,430 1,400 1,389 1,420 1,507 64 1,440 1,433 1,409 1,402 1,392 1,440 1,530 128 1,434 1,418 1,409 1,398 1,400 1,450 1,542 256 1,420 1,412 1,406 1,400 1,411 1,450 1,537 516 1,421 1,411 1,408 1,407 1,412 1,451 1,477 Table
