BS ISO 6980-3-2006 Nuclear energy - Reference beta-particle radiation - Calibration of area and personal dosemeters and the determination of their response as a function of beta ra.pdf

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2、nction of beta radiation energy and angle of incidenceICS 17.240Nuclear energy Reference beta-particle radiation BRITISH STANDARDBS ISO 6980-3:2006BS ISO 6980-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2006 BSI 2006ISBN

3、0 580 49404 7Amendments issued since publicationAmd. No. Date CommentsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National f

4、orewordThis British Standard was published by BSI. It is the UK implementation of ISO 6980-3:2006. Together with BS ISO 6980-1:2006 and BS ISO 6980-2:2004, it supersedes BS ISO 6980:1996 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee NCE/2, Radiation

5、protection and measurement.A list of organizations represented on NCE/2 can be obtained on request to its secretary.Reference numberISO 6980-3:2006(E)INTERNATIONAL STANDARD ISO6980-3First edition2006-10-01Nuclear energy Reference beta-particle radiation Part 3: Calibration of area and personal dosem

6、eters and the determination of their response as a function of beta radiation energy and angle of incidence nergie nuclaire Rayonnement bta de rfrence Partie 3: talonnage des dosimtres individuels et des dosimtres de zone et dtermination de leur rponse en fonction de lnergie et de langle dincidence

7、du rayonnement bta BS ISO 6980-3:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 2 3 Terms and definitions. 2 4 Procedures applicable to all area and personal dosemeters. 9 4.1 General principles. 9 4.2 Determination of the calibration factor and of the correc

8、tion factor 12 5 Particular procedures for area dosemeters . 13 5.1 General principles. 13 5.2 Quantities to be measured. 13 6 Particular procedures for personal dosemeters . 13 6.1 General principles. 13 6.2 Quantity to be measured 13 6.3 Experimental conditions 13 7 Presentation of results. 15 7.1

9、 Records and certificates 15 7.2 Statement of uncertainties. 15 Annex A (normative) Symbols and abbreviated terms 17 Annex B (normative) Reference conditions 19 Annex C (informative) Conversion coefficients for some beta reference radiation fields . 21 Bibliography . 23 BS ISO 6980-3:2006iv Foreword

10、 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 technical

11、 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 elec

12、trotechnical 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 the

13、 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 iden

14、tifying any or all such patent rights. ISO 6980-3 was prepared by Technical Committee ISO/TC 85, Nuclear energy, Subcommittee SC 2, Radiation protection. This first edition of ISO 6980-3, together with ISO 6980-1:2006 and ISO 6980-2:2004, cancels and replaces ISO 6980:1996, which has been technicall

15、y revised. ISO 6980 consists of the following parts, under the general title Nuclear energy Reference beta-particle radiation: Part 1: Methods of production Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field Part 3: Calibration of area and personal doseme

16、ters and the determination of their response as a function of beta radiation energy and angle of incidence BS ISO 6980-3:2006vIntroduction ISO 6980 covers the production, calibration and use of beta-particle reference radiation fields for the calibration of dosemeters and doserate meters for protect

17、ion purposes. ISO 6980-1 describes the methods of production and characterization of the reference radiation. ISO 6980-2 describes procedures for the determination of absorbed dose rate to a reference depth of tissue from beta particle reference radiation fields. This part of ISO 6980 describes proc

18、edures for the calibration of dosemeters and doserate meters and the determination of their response as a function of beta-particle energy and angle of beta-particle incidence. BS ISO 6980-3:2006blank1Nuclear energy Reference beta-particle radiation Part 3: Calibration of area and personal dosemeter

19、s and the determination of their response as a function of beta radiation energy and angle of incidence 1 Scope This part of ISO 6980 describes procedures for calibrating and determining the response of dosemeters and doserate meters in terms of the International Commission on Radiation Units and Me

20、asurements (ICRU) operational quantities for radiation protection purposes. However, as noted in ICRU Report 56, the ambient dose equivalent, H*(10), used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even that which penetrates 10 mm of

21、 tissue (Emax 2 MeV). For beta particles, the calibration and the determination of the response of dosemeters and doserate meters is essentially a three-step process. First, the basic field quantity, absorbed dose to tissue at a depth of 0,07 mm in a tissue-equivalent slab geometry is measured at th

22、e point of test, using methods described in ISO 6980-2. Then, the appropriate operational quantity is derived by the application of a conversion coefficient that relates the quantity measured (reference absorbed dose) to the selected operational quantity for the selected irradiation geometry. Finall

23、y, the reference point of the device under test is placed at the point of test for the calibration and determination of the response of the dosemeter. Depending on the type of dosemeter under test, the irradiation is either carried out on a phantom or free-in-air for personal and area dosemeters res

24、pectively. For individual and area monitoring, this part of ISO 6980 describes the methods and the conversion coefficients to be used for the determination of the response of dosemeters and doserate meters in terms of the ICRU operational quantities directional dose equivalent, H(0,07; G) and person

25、al dose equivalent, Hp(0,07). This part of ISO 6980 is a guide for those who calibrate protection-level dosemeters and doserate meters with beta-reference radiation and determine their response as a function of beta-particle energy and angle of incidence. Such measurements can represent part of a ty

26、pe test during the course of which the effect of other influence quantities on the response is examined. This part of ISO 6980 does not cover the in situ calibration of fixed, installed area dosemeters. The term “dosemeter” is used as a generic term denoting any dose or doserate meter for individual

27、 or area monitoring. In addition to the description of calibration procedures, this part of ISO 6980 includes recommendations for appropriate phantoms and the way to determine appropriate conversion coefficients. Guidance is provided on the statement of measurement uncertainties and the preparation

28、of calibration records and certificates. BS ISO 6980-3:20062 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (

29、including any amendments) applies. International vocabulary of basic and general terms in metrology (VIM), BIPM/IEC/IFCC/ISO/IUPAC/IUPAP/OIML ISO 6980-2:2004, Nuclear energy Reference beta-particle radiation Part 2: Calibration fundamentals related to basic quantities characterizing the radiation fi

30、eld ICRU Report 51, Quantities and Units in Radiation Protection Dosimetry 3 Terms and definitions For the purposes of this document, the terms and definitions given in ICRU Report 51, VIM and the following apply. 3.1 ICRU tissue material with a density of 1 gcm3and a mass composition of 76,2 % oxyg

31、en, 10,1 % hydrogen, 11,1 % carbon, and 2,6 % nitrogen NOTE See ICRU Report 39. 3.2 maximum beta energy Emaxhighest value of the energy of beta particles emitted by a particular nuclide which can emit one or several continuous spectra of beta particles with different maximum energies 3.3 mean beta e

32、nergy E fluence average energy of the beta particle spectrum at the calibration distance 3.4 residual maximum beta energy Ereshighest value of the energy of a beta particle spectrum at the calibration distance, after having been modified by scatter and absorption 3.5 absorbed dose D quotient of d by

33、 dm where d is the mean energy imparted by ionizing radiation to matter of mass, dm ddDm= (1) NOTE The unit of the absorbed dose is joule per kilogram (Jkg1) with the special name, gray (Gy). BS ISO 6980-3:200633.6 dose equivalent H product of Q and D at a point in tissue, where D is the absorbed do

34、se at that point and Q the quality factor at the point H = DQ (2) NOTE 1 The unit of the dose equivalent is joule per kilogram (Jkg1) with the special name, sievert (Sv). NOTE 2 For photon and beta radiation, the quality factor, Q, has a value very close to 1 SvGy1. In the absorbed-dose-to-dose-equi

35、valent conversion coefficient (see 3.12), the quality factor, Q, is included. 3.7 directional dose equivalent for weakly penetrating radiation ,;(0 07 )H Gdose equivalent that, at a point in a radiation field, would be produced by the corresponding expanded field in the ICRU sphere at a depth of 0,0

36、7 mm on a radius in a specified direction, GNOTE 1 The unit of the directional dose equivalent is joule per kilogram (Jkg1) with the special name, sievert (Sv). NOTE 2 In the expanded field, the fluence and its angular and energy distributions have the same value over the volume of interest as in th

37、e actual field at the point of measurement. 3.8 personal dose equivalent for weakly penetrating radiation Hp(0,07) dose equivalent in soft tissue below a specified point on the body at a depth of 0,07 mm NOTE 1 The unit of the personal dose equivalent is joule per kilogram (Jkg1) with the special na

38、me sievert (Sv). NOTE 2 In ICRU Report 47, the ICRU has considered the definition of the personal dose equivalent to include the dose equivalent at a depth of 0,07 mm in a phantom having the composition of the ICRU tissue. Then, Hp(0,07) for the calibration of personal dosemeters is the dose equival

39、ent at a depth of 0,07 mm in a phantom composed of ICRU tissue (see 3.1), but of the size and shape of the phantom used for the calibration (see 6.3.1). NOTE 3 In a unidirectional field, the direction can be specified in terms of the angle, , between the direction opposing the incident field and a s

40、pecified normal on the phantom surface. 3.9 reference absorbed dose DRpersonal absorbed dose, Dp(0,07), in a slab phantom made of ICRU tissue with an orientation of the phantom in which the normal to the phantom surface coincides with the (mean) direction of the incident radiation NOTE 1 The persona

41、l absorbed dose, Dp(0,07), is defined in ICRU Report 51. For the purposes of this part of ISO 6980, this definition is extended to a slab phantom. NOTE 2 The slab phantom is approximated with sufficient accuracy by the material surrounding the standard instrument (extrapolation chamber) used for the

42、 measurement of the beta radiation field. NOTE 3 DRis approximated with sufficient accuracy by the directional absorbed dose in the ICRU sphere, D(0,07; 0). BS ISO 6980-3:20064 3.10 conventional true value of directional dose equivalent Htbest estimate of the value of the quantity to be measured, de

43、termined by a primary or secondary standard or by a reference instrument that has been calibrated against a primary or secondary standard, for which, for the quantity directional dose equivalent, H(0,07; ),Gat a depth of 0,07 mm measured in the direction, ,Gthe conventional true value under calibrat

44、ion conditions defined by the angle, , is given by Equation (3): Rt(0,07; ) (0,07; ; )DH hsourceD=G(3) with “source” denoting the reference radiation field of the source at the calibration distance (specific combination of isotope, distance and filtering) and the angle of beta-particle incidence und

45、er calibration conditions NOTE 1 Any statement of absorbed-dose-to-dose-equivalent conversion coefficient (see 3.12) requires the statement of the type of dose equivalent, e.g. directional or personal dose equivalent. The conversion coefficient, hD, depends on the energy particle spectrum and, for t

46、he quantities H(0,07;G) and Hp(0,07), also on the direction distribution of the incident radiation (see ICRU Report 47:1992, Figure 2.1). Under calibration conditions, it is assumed that the direction, ,Gcoincides with the direction of incidence. Therefore, any directional dependence of the directio

47、nal and personal dose equivalent is given by the (mean) angle, , between the (mean) direction of incidence and the normal on the phantom surface. It is, therefore, useful to consider the conversion coefficient, hD(0,07; source; ) as a function of the spectral fluence of the reference radiation field

48、 as impacted by the geometry (source), and the angle of incidence, . The conversion coefficient for the directional dose equivalent is hD(0,07; source; ). NOTE 2 The conversion coefficients, hp,D(0,07; source; ) and hD(0,07; source; ) are approximately equal and no additional data are included. NOTE

49、 3 A conventional true value is, in general, regarded as being sufficiently close to the true value for the difference to be insignificant for the given purpose. EXAMPLE Within an organization, the result of a measurement obtained with a secondary standard instrument may be taken as the conventional true value of the quantity to be measured. 3.11 conventional true value of personal dose equivalent Hp,tconventional true value, determined by a primary or second