1、Designation: E170 15E170 15aStandard Terminology Relating toRadiation Measurements and Dosimetry1This standard is issued under the fixed designation E170; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis terminology generally covers terms that apply to radiation measurements and dosimetryassociated with energy deposition and radiat
3、ion effects, or damage, in materials caused by interactionsby high-energy radiation fields. The common radiation fields considered are X-rays, gamma rays,electrons, alpha particles, neutrons, and mixtures of these fields. This treatment is not intended to beexhaustive but reflects special and common
4、 terms used in technology and applications of interest toCommittee E10, as for example, in areas of radiation effects on components of nuclear power reactors,radiation hardness testing of electronics, and radiation processing of materials.This terminology uses recommended definitions and concepts of
5、 quantities, with units, for radiationmeasurements as contained in the International Commission on Radiation Units and Measurements(ICRU) Report 85a on “Fundamental Quantities and Units for Ionizing Radiation,” October20112011.2 Those terms that are defined essentially according to the terminology o
6、f ICRU Report 85awill be followed by ICRU in parentheses. It should also be noted that the units for quantities used arethe latest adopted according to the International System of Units (SI) which are contained inAppendixX1 as taken from a table in ICRU Report 85a.2 This terminology also uses recomm
7、ended definitionsof two ISO documentsJCGM documents,3, namely “International Vocabulary of Basic and GeneralTerms in Metrology.” (VIM, 2008) vocabulary of metrology” (VIM, 2012, unless indicated otherwise)and “Guide to the Expressionexpression of Uncertaintyuncertainty in Measurement”measurement”(GU
8、M, 1995).2008). Those terms that are defined essentially according to the terminology of thesedocuments will be followed by either VIM or GUM in parentheses.A term is boldfaced when it is defined in this standard. For some terms, text in italics is used justbefore the definition to limit its field o
9、f application, for example, see activity.1. Referenced Documents1.1 ASTM Standards:4E380 Practice for Use of the International System of Units (SI) (the Modernized Metric System) (Withdrawn 1997)5E456 Terminology Relating to Quality and StatisticsE706 Master Matrix for Light-Water Reactor Pressure V
10、essel Surveillance Standards, E 706(0) (Withdrawn 2011)5E722 Practice for Characterizing Neutron Fluence Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence forRadiation-Hardness Testing of ElectronicsE910 Test Method for Application and Analysis of Helium Accumulation Fluence Monitors f
11、or Reactor Vessel Surveillance,E706 (IIIC)1 This terminology is under the jurisdiction of ASTM Committee E10 on Nuclear Technology and Applications and is the direct responsibility of Subcommittee E10.93on Editorial.Current edition approved March 15, 2015Sept. 1, 2015. Published April 2015October 20
12、15. Originally approved in 1963. Last previous edition approved in 20142015 asE170 14a.E170 15. DOI: 10.1520/E0170-15.10.1520/E0170-15A.2 ICRU Report 60 has been supercededsuperseded by ICRU Report 85a on “Fundamental Quantities and Units for Ionizing Radiation,” October 2011. Both of thesedocuments
13、 are available from International Commission on Radiation Units and Measurements (ICRU), 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.3 Available from International Organization for Standardization (ISO), 1 Rue de Varembe, Case Postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.Docum
14、ent produced by Working Groups of the Joint Committee for Guides in Metrology (JCGM). Available free of charge at BIPM website (http:/www.bipm.org).4 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standar
15、dsvolume information, refer to the standards Document Summary page on the ASTM website.5 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what change
16、s have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the officia
17、l document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.2 ISO Standards:Joint Committee for Guides in Metrology (JCGM) Reports:3JCGM 100:2008, GUM 1995 , with minor corrections, Evaluation of measurement data Guide to the Express
18、ionexpression ofUncertainty in Measurement, ISO 1995uncertainty in measurementJCGM 200:2012, VIM International Vocabularyvocabulary of Basic and General Terms in Metrology, ISO 2008metrology Basic and general concepts and associated terms1.3 ICRU Documents:2ICRU 60 Fundamental Quantities and Units f
19、or Ionizing Radiation, December 30, 1998ICRU 85a Fundamental Quantities and Units for Ionizing Radiation, October, 20111.4 NIST Document:6NIST Technical Note 1297 Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results, 19942. Terminologyabsorbed dose (D)quotient of d by
20、 dm, where d is the mean incremental energy imparted by ionizing radiation to matterof incremental mass dm. (ICRU), thusD 5d/dm (1)DISCUSSIONThe SI unit of absorbed dose is the gray (Gy), where 1 gray is equivalent to the absorption of 1 joule per kilogram of the specified material (1 Gy= 1 J/kg). T
21、he unit rad (1 rad = 100 erg/g = 0.01 Gy) is still widely used in the nuclear community; however, its continued use is not encouraged. Fora photon source under conditions of charged particle equilibrium, the absorbed dose, D, may be expressed as follows:D 5Een/, (2)where: = fluence (m2),E = energy o
22、f the ionizing radiation (J), anden/ = mass energy absorption coefficient (m2/kg).If bremsstrahlung production within the specified material is negligible, the mass energy absorption coefficient (en/) is equal to the mass energytransfer coefficient (tr/), and absorbed dose is equal to kerma if, in a
23、ddition, charged particle equilibrium exists.absorbed dose rate (D)quotient of dD by dt where dD is the increment of absorbed dose in the time interval dt (ICRU), thusD 5dD/dt (3)SI unit: Gys1.DISCUSSIONThe absorbed-dose rate is often specified as an average value over a longer time interval, for ex
24、ample, in units of Gymin1 or Gyh1.accuracycloseness of agreement between a measurement result and an accepted reference value (see Terminology E456).activation cross sectioncross section for processes in which the product nucleus is radioactive (seea specific direct orcompound nuclear interaction in
25、 which cross sectionthe product). nucleus is radioactive.DISCUSSIONFission and spallation processes produce a statistical ensemble of outgoing nuclear channels, but they are not considered to be activation reactions.activity (A)of an amount of radionuclide in a particular energy state at a given tim
26、e, quotient of dN by dt, where dN is themean change in the number of nuclei in that energy state due to spontaneous nuclear transformations in the time interval dt(ICRU), thusA 52dN/dt (4)Unit: s1The special name for the unit of activity is the becquerel (Bq), where1Bq51s21 (5)6 Available from Natio
27、nal Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, USA, http:/www.nist.govE170 15a2DISCUSSIONThe former special unit of activity was the curie (Ci), where1Ci53.731010 s21 exactly!. (6)The negative sign in Eq 4 is an indication that the activity
28、is decreasing with time. The “particular energy state” is the ground state of the nuclideunless otherwise specified. The activity of an amount of radionuclide in a particular energy state is equal to the product of the decay constant forthat state and the number of nuclei in that state (that is, A =
29、 N). (See decay constant.)analysis bandwidthspectral band used in a photometric instrument, such as a densitometer, for the measurement of opticalabsorbance or reflectance.analysis wavelengthwavelength used in a spectrophotometric instrument for the measurement of optical absorbance orreflectance.an
30、nihilation radiationgamma radiation produced by the annihilation of a positron and an electron.DISCUSSIONFor particles at rest, two photons are produced, each having an energy corresponding to the rest mass of an electron (511 keV).backscatter peakpeak in the observed photon spectrum resulting from
31、large-angle (110) Compton scattering of gamma raysfrom materials near the detector.DISCUSSIONThis peak is normally below about 0.25 MeV. Also, it will not have the same shape as the full-energy peaks (being wider and skewed toward lowerenergy).benchmark neutron fieldwell-characterized neutron field
32、which will provide a fluence of neutrons for irradiation environmentwhich provides a fluence or fluence rate of neutrons suitable for the validation or calibration of experimental techniques andmethods and as well as for validation of cross sections and other nuclear data. Thedata, where following c
33、lassification ofbenchmark neutron fields for reactor dosimetry has been made:7controlled neutron fieldneutron field physically well-defined, and with some spectrum definition, employed for a restricted setof validation experiments.reference neutron fieldpermanent and reproducible neutron field less
34、well characterized than a standard field but accepted asa measurement reference by a community of users.standard neutron fieldpermanent and reproducible neutron field with that is characterized to state-of-the-art accuracy in termsof neutron fluence rate and energy spectra, and their associated spat
35、ial and angular distributions characterized to state-of-the-artaccuracy. Important field quantities must distributions, where important field quantities need to be verified by interlaboratorymeasurements and calculations.measurements.DISCUSSIONA type of neutron field is considered to be a “standard”
36、 over a specified energy range and there is only one type of “standard neutron field” for a givenenergy range. Currently, the 252Cf spontaneous fission field is a “standard neutron field” from 0.5 MeV to 8 MeV. The deuterium-tritium (DT)accelerator field is considered to be the “standard neutron fie
37、ld” from 13.5 to 15 MeV. The thermal Maxwellian and epithermal 1/E slowing-down fieldare also considered to be “standard neutron fields.”bremsstrahlungbroad-spectrum electromagnetic radiation emitted when an energetic charged particle is influenced by a strongelectric field, such as the Coulomb fiel
38、d of an atomic nucleus.DISCUSSIONIn radiation processing, bremsstrahlung photons are generated by the deceleration or deflection of energetic electrons in a target material. When anelectron passes close to an atomic nucleus, the strong Coulomb field causes the electron to deviate from its original m
39、otion. This interaction resultsin a loss of kinetic energy by the electron with the emission of electromagnetic radiation; the photon energy distribution extends up to the maximum7 The following three definitions are derived from: Neutron Cross Sections for Reactor Dosimetry, International Atomic En
40、ergy Agency, Laboratory Activities, Vienna,1978, Vol 1, p. 62.1978, p. 62 and Vlasov, M., IAEA Program on Benchmark Neutron Fields Applications for Reactor Dosimetry, Report INDC(SEC)-54/L+Dos, IAEA,Vienna, 1976.E170 15a3kinetic energy of the incident electron. This bremsstrahlung spectrum depends o
41、n the electron energy, the composition and thickness of the target, andthe angle of emission with respect to the incident electron.buildup factorfor radiation passing through a medium, ratio of the total value of a specified radiation quantity (such as absorbeddose) at any point in that medium to th
42、e contribution to that quantity from the incident uncollided radiation reaching that point.cadmium ratioratio of the neutron reaction rate measured with a given bare neutron detector to the neutron reaction ratemeasured with an identical neutron detector enclosed by a particular cadmium cover and ex
43、posed in the same neutron field atthe same or an equivalent spatial location.DISCUSSIONIn practice, meaningful experimental values can be obtained in an isotropic neutron field by using a cadmium filter approximately 1 mm thick.calibrated instrumentinstrument for which the response has been document
44、ed upon being directly compared with the responseof that has been through a standardcalibration instrument, both having been exposed to the same radiation field under the sameconditions; or one for which the response has been documented upon being exposed to a standard radiation field underwell-defi
45、ned conditions.process at established time intervals.DISCUSSIONMeasurements carried out by this instrument have metrological traceability to the reference standard if calibration is properly carried out.calibrationset of operations that establish, under specified conditions, the relationship between
46、 values of quantities indicated bya measuring instrument or measuring system, or values represented by a material measure or a reference material, and thecorresponding values realized by standards (VIM: 1993).DISCUSSION(1) Calibration conditions include environmental and irradiation conditions prese
47、nt during calibration.(2) These standards should have metrological traceability to a national or international standard.(3) To be reliable, calibration should be carried out at regular time intervals frequency may depend on the final use of thedata. Often, the frequency is specified by regulatory au
48、thorities.calibration source or fieldsee electron standard field, -raygamma-ray standard field, and X-ray standard field.calorimeterinstrument capable of making absolute measurements of energy deposition (or absorbed dose) in a material throughmeasurement of its change in temperature and a knowledge
49、 of the characteristics of its material construction.certified reference materialmaterial that has been characterized by a recognized standard or testing laboratory, for some of itschemical or physical properties, and that is generally used for calibration of a measurement system, or for development orevaluation of a measurement method.DISCUSSIONCertification of a reference material can be obtained by one of the following three established routes of measurement of properties: (1) using apreviously valida
