ISO INTERNATIONAL STANDARD 4037-1 Second edition 2019-01 Radiological protection 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 Radioprotection - Rayonnements X et gamma de réference pour I'étalonnage des dosimetres et des débitmetres, et pour la détermination de leur reponse en fonction de I'energie des photons - Partie 1: Caractéristiques des rayonnements et méthodes de production Reference number ISO 4037-1:2019(E) os1 @ IS0 2019 IS0 4037-1:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 4037-1:2019(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. 2 Normative references ...3. 3 Terms and definitions 4 Continuous reference filtered X radiation ..7 4.1 General .7 4.1.1 Realisation of reference radiation fields .7 4.1.2 Basis of conversion coefficients. .7 4.1.3 Radiation quality.. ..8 4.1.4 Choiceofreferenceradiation 4.2 Conditions and methods for producing reference X radiation ..13 4.2.1 Characteristics of the high voltage generator ..13 4.2.2 Tube potential and protective resistor.. ..14 4.2.3 Filtration. .15 4.2.4 Limitations concerning matched fields. .19 4.2.5 X radiation shutter. 20 4.2.6 Beam aperture 20 4.3 Field uniformity and scattered radiation 20 4.3.1 Field diameter. 20 4.3.2 Field uniformity 20 4.3.3 Scatteredradiation 20 4.4 Summary of the requirements for reference X radiation fields 21 4.5 Validation of reference X radiation 21 4.5.1 General 21 4.5.2 Criteria for validation by HVL determination 22 4.5.3 Apparatus for HVL measurement 23 4.5.4 HVL measurement procedure.. 24 4.5.5 Criteria for validation by dosimetry 24 4.5.6 Criteria for validation by spectrometry 24 5 Gamma radiation emitted by radionuclides ..25 5.1 General .25 5.2 Radionuclides used for the production of gamma radiation. 25 5.3 Specification of radiation sources 25 5.3.1 Sources 25 5.3.2 Encapsulation .26 5.4 Irradiation facility and influence of scattered radiation .26 5.4.1 General requirements. 26 5.4.2 Collimated geometry installation 26 5.4.3 Variation of air kerma rate by means of lead attenuators. 27 5.5 Checking installation conformity. .27 6 Photon radiation with energies between 4 MeV and 9 MeV .28 6.1 General. 28 6.2 Production of reference radiation. .28 6.2.1 General. 28 6.2.2 Photon reference radiation from de-excitation of 160 in the 19F(p, αy)160 reaction .28 6.2.3 Photon reference radiation from de-excitation of 12C .30 6.3 Beam diameter and uniformity of radiation field .31 6.4 Contamination of photon reference radiation. .31 6.4.1 General 31 @ IS0 2019 - All rights reserved ii