BS ISO 4037-1-1998 X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy - Radiation char.pdf

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1、BRITISH STANDARD BS ISO 4037-1:1996 X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy Part 1: Radiation characteristics and production methods ICS 17.240BSISO4037-1:1996 This British Standard, having been

2、prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15 March1998 BSI 10-1999 ISBN 0 580 29619 9 National foreword This British Standard reproduces verbatim ISO4037-1:1996 and implements it as the UK national stan

3、dard. In conjunction with BS ISO4037-2:1997, it supersedes BS5869:1980 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee NCE/2, Health physics instrumentation, which has the responsibility to: aid enquirers to understand the text; present to the respons

4、ible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on requ

5、est to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of t

6、he BSI Standards Electronic Catalogue. 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. Su

7、mmary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pagesii toiv, pages1 to36 and aback cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on th

8、e inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO4037-1:1996 BSI 10-1999 i Contents Page National foreword Inside front cover Foreword iv Text of ISO 4037-1 1ii blankBSISO4037-1:1996 ii BSI 10-1999 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 De

9、finitions 1 4 Continuous reference filtered X radiation 3 5 Fluorescence X radiation 9 6 Gamma radiation emitted by radionuclides 12 7 Photon radiation with energy between eV and9MeV15 Annex A (informative) Bibliography 35 Figure 1 Low air-kerma rate series spectra 19 Figure 2 Narrow-spectrum series

10、 21 Figure 3 Wide-spectrum series 23 Figure 4 High air-kerma rate series spectra 24 Figure 5 Uranium spectrum 26 Figure 6 Schematic diagram of a K-fluorescence X-ray installation 27 Figure 7 Example of a collimated installation 28 Figure 8 Energy levels and emission probabilities of photon radiation

11、 from the decay of 16 N (left) and from the de-excitation of 16 O for an incident proton energy of340,5keV on 19 F (right)22 29 Figure 9 Thin-target photon yield as a function of proton energy for the 19 F(p, !*) 16 O reaction 30 Figure 10 Example of the photon fluence spectrum of6MeV to7MeV referen

12、ce radiation, proton energy2,7MeV 31 Figure 11 Example of the photon fluence spectrum of the4,4MeV reference radiation, proton energy5,5MeV 32 Figure 12 Photon spectrum of “titanium beam” 33 Figure 13 Photon spectrum of a “nickel beam” 34 Figure 14 Example of an irradiation facility for production o

13、f capture gamma radiation 34 Table 1 List of X and gamma reference radiation and their mean energies 2 Table 2 Specifications of filtered X radiation 5 Table 3 Characteristics of low air-kerma rate series 5 Table 4 Characteristics of narrow-spectrum series 6 Table 5 Characteristics of wide-spectrum

14、series 6 Table 6 Characteristics of high air-kerma rate series 7 Table 7 Approximate characteristics of high air-kerma rate series 7 Table 8 Inherent filtration 8 Table 9 Metal properties 8 Table 10 Radiators and filters used for K-fluorescence reference radiation 10 Table 11 Examples of air-kerma r

15、ates and extraneous radiation measured30cm from the radiator centre with a tube current of10mA 12 Table 12 Radionuclide properties 13 Table 13 Specific activity and recommended chemical form of radioactive nuclides 13 Table 14 Example of composition of aperture alloy used in the collimator of Figure

16、 7 14BSISO4037-1:1996 BSI 10-1999 iii Page Table 15 Typical photon yields and air-kerma rates for specified proton energies and14A proton current 16 Table 16 Principal photon yields of titanium and nickel per100 neutron captures 18 Table 17 Capture gamma radiation Examples of targets, air-kerma rate

17、s and reference energies obtained26 18 Descriptors: Nuclear radiation, radiation protection, radiation measuring instruments, exposure dose-rate meters, calibration, reference sources, gamma radiation, X rays.BSISO4037-1:1996 iv BSI 10-1999 Foreword ISO (the International Organization for Standardiz

18、ation) 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 committee has been established has the right to be

19、 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 electrotechnical standardization. Draft International S

20、tandards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO4037-1 was prepared by Technical Committee ISO/TC85, Nuclear energy, S

21、ubcommittee SC2, Radiation protection. This first edition of ISO4037-1, along with ISO-4037-2, cancels and replaces the first edition of ISO4037:1979, which has been technically revised. ISO4037 consists of the following parts, under the general title X and gamma reference radiation for calibrating

22、dosemeters and doserate meters and for determining their response as a function of photon energy. Part 1: Radiation characteristics and production methods; Part 2: Dosimetry of X and gamma reference radiation for radiation protection over the energy ranges8keV to1,3MeV and4MeV to9MeV. Annex A of thi

23、s part of ISO4037 is for information only.BSISO4037-1:1996 BSI 10-1999 1 1 Scope This part of ISO4037 specifies the characteristics and production methods of X and gamma reference radiation for calibrating protection-level dosemeters and rate dosemeters at air kerma rates from104Gyh 1to10 Gyh 1and f

24、or determining their response as a function of photon energy. The methods for producing a group of reference radiations for a particular photon-energy range are described in four sections which define the characteristics of these radiations. The four groups of reference radiation are: a) in the ener

25、gy range from about7keV to250keV, continuous filtered X radiation and the gamma radiation of americium-241; b) in the energy range8keV to100keV, fluorescence X radiation; c) in the energy range600keV to1,3MeV, gamma radiation emitted by radionuclides; d) in the energy range4MeV to9MeV, gamma radiati

26、on produced by reactors and accelerators. These reference radiations should be selected from Table 1. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO4037. At the time of the publication, the editions i

27、ndicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO4037 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 Intern

28、ational Standards. ISO197-1:1983, Copper and copper alloys Terms and definitions Part1: Materials. ISO1677:1977, Sealed radioactive sources General. ISO3534-1:1993, Statistics Vocabulary and symbols Part1: Probability and general statistical terms. ISO8963:1988, Dosimetry of X and gamma reference ra

29、diations for radiation protection over the energy range from8keV to1,3MeV. ICRU Report10b, Physical Aspects of Irradiation, National Bureau of Standards Handbook85(1964). 3 Definitions For the purposes of this part of ISO4037, the following definitions apply: 3.1 mean photon energy, ratio defined by

30、 the formula: where Eis the derivative of the fluence Eof the primary photons of energy E with respect to energies between E and E + dE1, defined as In this part of ISO4037, this definition is abbreviated to “mean energy” 3.2 spectral resolution, R E(full width at halfmaximum) ratio, expressed as a

31、percentage, defined by the formula: where increment %E is the spectrum width corresponding to half the maximum ordinate of the spectrum NOTEIn the case where fluorescence radiation is present in the spectrum, the spectrum width measured is based upon the continuum only. In this part of ISO4037 this

32、definition is abbreviated to resolution 3.3 half-value layer (air kerma), HVL or HVL x 2 thickness of the specified material which attenuates the beam of radiation to an extent such that the air kerma rate is reduced to half of its original value in this definition, the contribution of all scattered

33、 radiation, other than any which might be present initially in the beam concerned, is deemed to be excluded EBSISO4037-1:1996 2 BSI 10-1999 Table 1 List of X and gamma reference radiation and their mean energies Values in kiloelectronvolts Fluorescence X radiation, mean energy Mean energy, filtered

34、X radiation Gamma radiation, mean energy Low air-kerma rate series Narrow-spectrum series Wide-spectrum series High air-kerma rate series 8,6 8,5 8 7,5 9,9 12 13 15,8 16 17,5 17 20 20 23,2 24 25,3 26 30 31 33 37,4 37 40,1 45 48 48 49,1 59,3 60 57 57 59,5 ( 241Am) 65 68,8 75,0 79 98,4 87 83 100 104 1

35、02 109 118 122 149 137 146 147 164 173 185 208 208 211 250 662( 137 Cs) 1173 and 1333 ( 60 Co) 4 440 ( 12 C) 6000 (Ti) 6 130 a 16 O *and 16 N 8 500 (Ni) a When produced by protons of energy near the reaction theshold, see7.1).BSISO4037-1:1996 BSI 10-1999 3 3.4 homogeneity coefficient, h ratio of the

36、 first half-value layer to the second half-value layer (air kerma): 3.5 effective energy, E eff(of radiation comprised of X-rays with a range of energies) energy of the monoenergetic X-rays which have the same HVL 3.6 value of peak-to-peak voltage; ripple ratio, expressed as a percentage, defined fo

37、r a given current by the formula: where U maxis the maximum value and U minthe minimum value between which the voltage oscillates 3.7 X-ray unit assembly comprising a high-voltage supply, an X-ray tube with its protective housing, and high-voltage electrical connections 3.8 X-ray tube vacuum tube de

38、signed to produce X-rays by bombardment of the anode by a beam of electrons accelerated through a potential difference 3.9 monitor instrument used to monitor the stability of the air kerma rate during irradiation or to compare values of air kerma after successive irradiations 3.10 primary radiation

39、(or beam) radiation or beam emitted by the X-ray tube 3.11 secondary fluorescence radiation radiation or beam emitted by a radiator 3.12 X-ray tube shielding fixed or mobile panel intended to reduce the contribution of scatter X-radiation to the primary or fluorescence (secondary) beam 4 Continuous

40、reference filtered X radiation 4.1 General This clause specifies the characteristics of the reference filtered X radiation and the method by which a laboratory can produce a specified reference radiation. 4.1.1 Radiation quality The quality of a filtered X radiation is characterized in this part of

41、ISO4037 by the following parameters: a) mean energy, , of a beam, expressed in kiloelectronvolts (keV); b) resolution, R E , expressed in percent; c) half-value layer (air kerma), HVL, expressed in millimetres of Al or Cu; d) homogeneity coefficient, h. In practice, the quality of the radiation obta

42、ined depends primarily on the high-voltage across the X-ray tube, the thickness and nature of the total filtration, and the properties of the target. In order to ensure the production of the reference radiation in conformance with the given specifications, the installation shall comply with certain

43、conditions. These are described in4.2. 4.1.2 Choice of reference radiation This part of ISO4037 specifies four series of reference radiation (see Table 2), each series being characterized by the resolution of the spectrum: a) a low air-kerma rate series (see Figure 1); b) a narrow-spectrum series (s

44、ee Figure 2); c) a wide-spectrum series (see Figure 3); d) a high air-kerma rate series (see Figure 4). The spectra shown in Figure 1 to Figure 4 are for the most part based upon theoretical calculations3 and are only given as examples. Some practical spectra are also included and examples of practi

45、cal measurements of spectra are given in references4,5,6,7 and8. The narrowest spectra, i.e.those with the lowest resolution, should be used for measurements of the variation of the response of an instrument with proton energy, provided that the air-kerma rates of that series are consistent with the

46、 range of the instrument under test. The high air-kerma rate series is suitable for determining the overload characteristics of some instruments. EBSISO4037-1:1996 4 BSI 10-1999 Details of the operating conditions for each of the four series are given in Table 3, Table 4, Table 5 and Table 6. Table

47、7 shows an example of the additional filtration required to produce the radiation qualities of the high air-kerma rate series for particular values of the fixed filtration. For the lower air-kerma rate, the narrow-spectrum and the wide-spectrum series, a “reference laboratory” shall verify, by a spe

48、ctrometric study, that the value of the mean energy produced is within 3%, and the resolution, R E , of the spectra is within 10% of the values listed in Table 3, Table 4 and Table 5. For reference radiation for these three series having mean energies lower than30keV, the mean energies shall be with

49、in 5% and the resolutions within 15% of the values in Table 3, Table 4 and Table 5. For reference radiation using additional filtration of1mm AI or less, the target angle, target condition and air path strongly influence the values of the mean energies, resolutions and HVLs. If a laboratory does not have a spectrometry system, the high voltages and filtration characteristics listed in Table 3, Table 4 and Table 5 shall be used and the reference r