BS ISO 6980-3-2006 en_3744 Nuclear energy - Reference beta-particle radiation - Calibration of area and personal dosemeters and the determination of their response as a function of b.pdf

1、BRITISH STANDARD BS ISO 6980-3:2006 Nuclear energy Reference beta-particle radiation Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence ICS 17.240 BS ISO 6980-3:2006 This British Standard was publi

2、shed under the authority of the Standards Policy and Strategy Committee on 31 October 2006 BSI 2006 ISBN 0 580 49404 7 National foreword This 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

3、BS ISO 6980:1996 which is withdrawn.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 NCE/2 can be obtained on request to its secretary. This publication does not purport to include all th

4、e necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. Date Comments Reference number ISO 6980-3:2006(E)INTERNATIONAL STANDARD ISO 6980-3 F

5、irst edition 2006-10-01 Nuclear energy Reference beta-particle radiation Part 3: Calibration of area and personal dosemeters 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 dosimt

6、res individuels et des dosimtres de zone et dtermination de leur rponse en fonction de lnergie et de langle dincidence du rayonnement bta BS ISO 6980-3:2006ii iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 2 3 Terms and definitions. 2 4 Procedures applicable to all

7、 area and personal dosemeters. 9 4.1 General principles. 9 4.2 Determination of the calibration factor and of the correction 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.

8、1 General principles. 13 6.2 Quantity to be measured 13 6.3 Experimental conditions 13 7 Presentation of results. 15 7.1 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 (informativ

9、e) Conversion coefficients for some beta reference radiation fields . 21 Bibliography . 23 BS ISO 6980-3:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards

10、is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical 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 pa

11、rt in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical 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

12、prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the 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 th

13、at some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying 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

14、6980-3, together with ISO 6980-1:2006 and ISO 6980-2:2004, cancels and replaces ISO 6980:1996, which has been technically 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 fun

15、damentals related to basic quantities characterizing the radiation field Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence BS ISO 6980-3:2006v Introduction ISO 6980 covers the production, calibrat

16、ion and use of beta-particle reference radiation fields for the calibration of dosemeters and doserate meters for protection 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 dos

17、e rate to a reference depth of tissue from beta particle reference radiation fields. This part of ISO 6980 describes procedures 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

18、 ISO 6980-3:2006blank1 Nuclear energy Reference beta-particle radiation Part 3: Calibration of area and personal dosemeters 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 det

19、ermining the response of dosemeters and doserate meters in terms of the International Commission on Radiation Units and Measurements (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

20、strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even that which penetrates 10 mm of tissue (E max 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

21、 basic field quantity, absorbed dose to tissue at a depth of 0,07 mm in a tissue-equivalent slab geometry is measured at the 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 qua

22、ntity measured (reference absorbed dose) to the selected operational quantity for the selected irradiation geometry. Finally, 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 d

23、osemeter under test, the irradiation is either carried out on a phantom or free-in-air for personal and area dosemeters respectively. 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 do

24、semeters and doserate meters in terms of the ICRU operational quantities directional dose equivalent, H(0,07; ) and personal dose equivalent, H p (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 determi

25、ne their response as a function of beta-particle energy and angle of incidence. Such measurements can represent part of a type 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,

26、installed area dosemeters. The term “dosemeter” is used as a generic term denoting any dose or doserate meter for individual 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

27、appropriate conversion coefficients. Guidance is provided on the statement of measurement uncertainties and the preparation 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. F

28、or dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (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 Re

29、ference beta-particle radiation Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field 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 Re

30、port 51, VIM and the following apply. 3.1 ICRU tissue material with a density of 1 gcm 3and a mass composition of 76,2 % oxygen, 10,1 % hydrogen, 11,1 % carbon, and 2,6 % nitrogen NOTE See ICRU Report 39. 3.2 maximum beta energy E maxhighest value of the energy of beta particles emitted by a particu

31、lar nuclide which can emit one or several continuous spectra of beta particles with different maximum energies 3.3 mean beta energy E fluence average energy of the beta particle spectrum at the calibration distance 3.4 residual maximum beta energy E reshighest value of the energy of a beta particle

32、spectrum at the calibration distance, after having been modified by scatter and absorption 3.5 absorbed dose D quotient of d by dm where d is the mean energy imparted by ionizing radiation to matter of mass, dm d d D m = (1) NOTE The unit of the absorbed dose is joule per kilogram (Jkg 1 ) with the

33、special name, gray (Gy). BS ISO 6980-3:20063 3.6 dose equivalent H product of Q and D at a point in tissue, where D is the absorbed dose 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 (Jkg 1 ) with the special name, sievert

34、 (Sv). NOTE 2 For photon and beta radiation, the quality factor, Q, has a value very close to 1 SvGy 1 . In the absorbed- dose-to-dose-equivalent conversion coefficient (see 3.12), the quality factor, Q, is included. 3.7 directional dose equivalent for weakly penetrating radiation ,; (0 07 ) H dose

35、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 0,07 mm on a radius in a specified direction, NOTE 1 The unit of the directional dose equivalent is joule per kilogram (Jkg 1 ) with the special name, sievert (Sv)

36、. 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 the actual field at the point of measurement. 3.8 personal dose equivalent for weakly penetrating radiation H p (0,07) dose equivalent in soft tissue below a spe

37、cified point on the body at a depth of 0,07 mm NOTE 1 The unit of the personal dose equivalent is joule per kilogram (Jkg 1 ) with the special name 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

38、 of 0,07 mm in a phantom having the composition of the ICRU tissue. Then, H p (0,07) for the calibration of personal dosemeters is the dose equivalent 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).

39、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 specified normal on the phantom surface. 3.9 reference absorbed dose D Rpersonal absorbed dose, D p (0,07), in a slab phantom made of ICRU tissue with an

40、orientation of the phantom in which the normal to the phantom surface coincides with the (mean) direction of the incident radiation NOTE 1 The personal absorbed dose, D p (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. N

41、OTE 2 The slab phantom is approximated with sufficient accuracy by the material surrounding the standard instrument (extrapolation chamber) used for the measurement of the beta radiation field. NOTE 3 D Ris approximated with sufficient accuracy by the directional absorbed dose in the ICRU sphere, D(

42、0,07; 0). BS ISO 6980-3:20064 3.10 conventional true value of directional dose equivalent H tbest estimate of the value of the quantity to be measured, determined by a primary or secondary standard or by a reference instrument that has been calibrated against a primary or secondary standard, for whi

43、ch, for the quantity directional dose equivalent, H(0,07; ), at a depth of 0,07 mm measured in the direction, , the conventional true value under calibration conditions defined by the angle, , is given by Equation (3): R t (0,07; ) (0,07; ; ) D H hs o u r c e D = (3) with “source” denoting the refer

44、ence radiation field of the source at the calibration distance (specific combination of isotope, distance and filtering) and the angle of beta-particle incidence under calibration conditions NOTE 1 Any statement of absorbed-dose-to-dose-equivalent conversion coefficient (see 3.12) requires the state

45、ment of the type of dose equivalent, e.g. directional or personal dose equivalent. The conversion coefficient, h D , depends on the energy particle spectrum and, for the quantities H(0,07; ) and H p (0,07), also on the direction distribution of the incident radiation (see ICRU Report 47:1992, Figure

46、 2.1). Under calibration conditions, it is assumed that the direction, , coincides with the direction of incidence. Therefore, any directional dependence of the directional and personal dose equivalent is given by the (mean) angle, , between the (mean) direction of incidence and the normal on the ph

47、antom surface. It is, therefore, useful to consider the conversion coefficient, h D (0,07; source; ) as a function of the spectral fluence of the reference radiation field as impacted by the geometry (source), and the angle of incidence, . The conversion coefficient for the directional dose equivale

48、nt is h D (0,07; source; ). NOTE 2 The conversion coefficients, h p,D (0,07; source; ) and h D (0,07; source; ) are approximately equal and no additional data are included. NOTE 3 A conventional true value is, in general, regarded as being sufficiently close to the true value for the difference to b

49、e 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 H p,tconventional true value, determined by a primary or secondary standard, or by a reference instrume