BS-5775-10-1993 ISO-31-10-1992.pdf

BRITISH STANDARD BS 5775-10: 1993 ISO 31-10: 1992 Specification for Quantities, units and symbols Part 10: Nuclear reactions and ionizing radiations UDC 389.15/.16:539.16/.17:006.72 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5775-10:1993 This British Standard, having been prepared under the direction of the Systems Department Steering Committee, was published under the authority of the Standards Board and comes into effect on 15 March 1993 © BSI 07-1999 First published September 1982 Second edition March 1993 The following BSI references relate to the work on this standard: Committee reference S/1 Draft for comment 90/55633 DC ISBN 0 580 22003 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Systems Department Steering Committee (S/-) to Technical Committee S/1, upon which the following bodies were represented: Chartered Institution of Building Services Engineers Department of Trade and Industry (National Physical Laboratory) Department of Trade and Industry (National Weights and Measures Laboratory) EEA (The Association of Electronics, Telecommunications and Business Equipment Industries) Institute of Physics Institute of Trading Standards Administration Institution of Chemical Engineers Institution of Electrical Engineers Institution of Mechanical Engineers Institution of Structural Engineers Royal Society Royal Society of Chemistry Schools Mathematics Project Society of Chemical Industry Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5775-10:1993 © BSI 07-1999i Contents Page Committees responsibleInside front cover National forewordii Introduction1 1Scope2 2Normative references2 3Names and symbols2 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5775-10:1993 ii © BSI 07-1999 National foreword This Part of BS 5775 has been prepared under the direction of the Systems Department Steering Committee. It is identical with ISO 31-10:1992 Quantities and units Part 10: Nuclear reactions and ionizing radiations, published by the International Organization for Standardization (ISO). ISO 31-10 was prepared by Technical Committee ISO/TC 12 “Quantities, units, symbols, conversion factors” with the active participation and approval of the UK. This Part of BS 5775 supersedes BS 5775-10:1982, which is withdrawn. The principal changes made in this revised version are as follows: a) the decision by the International Committee for Weights and Measures (Comité International des Poids et Mesures, CIPM) in 1980 concerning the status of supplementary units has been incorporated; b) units in use temporarily have been transferred to the “Conversion factors and remarks” column; c) the annex has been deleted. BS 5775 comprises the following Parts, each of which is identical with the corresponding Part of ISO 31. Part 0: General principles; Part 1: Space and time; Part 2: Periodic and related phenomena; Part 3: Mechanics; Part 4: Heat; Part 5: Electricity and magnetism; Part 6: Light and related electromagnetic radiations; Part 7: Acoustics; Part 8: Physical chemistry and molecular physics; Part 9: Atomic and nuclear physics; Part 10: Nuclear reactions and ionizing radiations; Part 11: Mathematical signs and symbols for use in the physical sciences and technology; Part 12: Characteristic numbers; Part 13: Solid state physics. Cross references International standardCorresponding British Standard ISO 31-6:1992 BS 5775 Specification for quantities, units and symbols Part 6:1993 Light and related electromagnetic radiations (Identical) ISO 31-9:1992Part 9:1993 Atomic and nuclear physics (Identical) Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5775-10:1993 © BSI 07-1999iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 26, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 31-10:1992(E) © BSI 07-19991 Introduction 0.1 Arrangement of the tables The tables of quantities and units in ISO 31 are arranged so that the quantities are presented on the left-hand pages and the units on the corresponding right-hand pages. All units between two full lines belong to the quantities between the corresponding full lines on the left-hand pages. Where the numbering of an item has been changed in the revision of a part of ISO 31, the number in the preceding edition is shown in parentheses on the left-hand page under the new number for the quantity; a dash is used to indicate that the item in question did not appear in the preceding edition. 0.2 Tables of quantities The most important quantities within the field of this document are given together with their symbols and, in most cases, definitions. These definitions are given merely for identification; they are not intended to be complete. The vectorial character of some quantities is pointed out, especially when this is needed for the definitions, but no attempt is made to be complete or consistent. In most cases only one name and only one symbol for the quantity are given; where two or more names or two or more symbols are given for one quantity and no special distinction is made, they are on an equal footing. When two types of italic (sloping) letter exist (for example as with H, Ú, Î, Ì, g, g) only one of these is given. This does not mean that the other is not equally acceptable. In general it is recommended that such variants should not be given different meanings. A symbol within parentheses implies that it is a “reserve symbol”, to be used when, in a particular context, the main symbol is in use with a different meaning. 0.3 Tables of units 0.3.1 General Units for the corresponding quantities are given together with the international symbols and the definitions. For further information, see ISO 31-0. The units are arranged in the following way: a) The names of the SI units are given in large print (larger than text size). The SI units have been adopted by the General Conference on Weights and Measures (Conference Générale des Poids et Mesures, CGPM). The SI units and their decimal multiples and sub-multiples are recommended, although the decimal multiples and sub-multiples are not explicitly mentioned. b) The names of non-SI units which may be used together with SI units because of their practical importance or because of their use in specialized fields are given in normal print (text size). These units are separated by a broken line from the SI units for the quantities concerned. c) The names of non-SI units which may be used temporarily together with SI units are given in small print (smaller than text size) in the “Conversion factors and remarks” column. d) The names of non-SI units which should not be combined with SI units are given only in annexes in some parts of ISO 31. These annexes are informative and not integral parts of the standard. They are arranged in three groups: 1) special names of units in the CGS system; 2) names of units based on the foot, pound and second and some other related units; 3) names of other units. 0.3.2 Remark on units for quantities of dimension one The coherent unit for any quantity of dimension one is the number one (1). When the value of such a quantity is expressed, the unit 1 is generally not written out explicitly. Prefixes shall not be used to form multiples or submultiples of this unit. Instead of prefixes, powers of 10 may be used. EXAMPLES Refractive index n = 1,53 × 1 = 1,53 Reynolds number Re = 1,32 × 103 Considering that plane angle is generally expressed as the ratio between two lengths, and solid angle as the ratio between an area and the square of a length, the CIPM specified in 1980 that, in the International System of Units, the radian and steradian are dimensionless derived units. This implies that the quantities plane angle and solid angle are considered as dimensionless derived quantities. The units radian and steradian may be used in expressions for derived units to facilitate distinction between quantities of different nature but having the same dimension. 0.4 Numerical statements All numbers in the “Definition” column are exact. When numbers in the “Conversion factors and remarks” column are exact, the word “exactly” is added in parentheses after the number. 0.5 Special remarks In this part of ISO 31, the term “particle” includes particles without a rest mass as well as particles having a rest mass. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 31-10:1992(E) 2 © BSI 07-1999 Several quantities given in this part of ISO 31 are spectral concentrations expressed in terms of energy, speed, solid angle, etc. The subscripts E, v and Ë are used as part of the symbol to indicate that the quantity has the dimension of a derivative with respect to E, v and Ë respectively. Spectral concentrations are also called distribution functions. The name of a quantity which is a spectral concentration may be shortened by replacing the words “spectral concentration of” by the adjective “spectral”. In general, these distribution functions are only mentioned in the remarks column; see for example 10-12, 10-29, 10-31 and 10-32. In the case of cross-sections, some of these distribution functions are given special names and are listed as separate items. 1 Scope This part of ISO 31 gives names and symbols for quantities and units of nuclear reactions and ionizing radiations. Where appropriate, conversion factors are also given. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 31. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 31 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 31-6:1992, Quantities and units Part 6: Light and related electromagnetic radiations. ISO 31-9:1992, Quantities and units Part 9: Atomic and nuclear physics. 3 Names and symbols The names and symbols for quantities and units of nuclear reactions and ionizing radiations are given on the following pages. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 31-10:1992(E) © BSI 07-19993 NUCLEAR REACTIONS AND IONIZING RADIATIONSQuantities Item No.QuantitySymbolDefinitionRemarks 10-1reaction energyQIn a nuclear reaction, the sum of the kinetic and photon energies of the reaction products minus the sum of the kinetic and photon energies of the reactant For exothermic nuclear reactions, Q 0. For endothermic nuclear reactions, Q 0. For beta disintegration, see ISO 31-9. 10-2resonance energyEr, EresKinetic energy of an incident particle, in the reference frame of the target, corresponding to a resonance in a nuclear reaction 10-3.1 10-3.2 cross-section total cross section Ö Ötot, ÖT For a specified target entity and for a specified reaction or process produced by incident charged or uncharged particles of specified type and energy, the cross-section is the probability of this reaction or process for this target entity divided by the incident-particle fluence The sum of all cross-sections corresponding to the various reactions or processes between an incident particle of specified type and energy and a target particle The type of process is indicated by subscripts, e.g. absorption cross-section Öa scattering cross-section Ös fission cross-section Öf. In the case of a narrow unidirectional beam of incident particles, this is the effective cross-section for the removal of an incident particle from the beam. See remark on 10-16. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 31-10:1992(E) 4 © BSI 07-1999 UnitsNUCLEAR REACTIONS AND IONIZING RADIATIONS Item No.Name of unitInternational symbol for unit DefinitionConversion factors and remarks 10-1.ajouleJ 10-1.belectronvolteV 1 eV = (1,602 177 33 ± 0,000 000 49) × 1019 Ja Quantity 10-1 is usually expressed in electronvolts. a CODATA Bulletin 63 (1986). 10-2.ajouleJ 10-2.belectronvolteV 1 eV = (1,602 177 33 ± 0,000 000 49) × 1019 Ja Quantity 10-2 is usually expressed in electronvolts. a CODATA Bulletin 63 (1986). 10-3.asquare metre m2barn (b), 1 b = 1028 m2 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:59:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 31-10:1992(E) © BSI 07-19995 NUCLEAR REACTIONS AND IONIZING RADIATIONSQuantities Item No.QuantitySymbolDefinitionRemarks 10-4angular cross-section ÖËCross-section for ejecting or scattering a particle into an element of solid angle, divided by this element. Quantities 10-4, 10-5 and 10-6 are sometimes called differential cross-sections. In accordance with conventions used in other parts of ISO 31, angular and spectral cross-sections are indicated by the use of subscripts. Information about incoming and outgoing particles may be added between parantheses, e.g. ÖË, E(nE0, pEÜ) or ÖË, E(nE0, p) or ÖË, E(n, p). The cross section for a process in which an incoming neutron of energy E0 causes the ejection of a proton within the energy interval (E, E + dE) and in the element of solid angle dË, about the scattering angle Ü is ÖË, E (nE0, pEÜ) dË dE. Sometimes the incoming and outgoing particles are indicated by subscripts, in which case the subscript Ë or E indicating the angular or spectral character could be places in the superscript position, e.g. or. if, however the subscripts Ë or E are omitted completely from the cross-section symbol, the angular or spectral character of the cross-section then follows only from the occurence of the variable Ü or E for the outgoing particles between the parentheses, e.g. Ön, p(E0, EÜ) or Ön, p(EÜ). These variables should then never be omitted. 10-5spectral cross-section ÖECross-section for a process in which