1、Designation: E3083 17Standard Terminology Relating toRadiation Processing: Dosimetry and Applications1This standard is issued under the fixed designation E3083; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis terminology covers terms that apply to radiation processing using ionizing radiation. Thecommon radiation fields considered
3、 are gamma radiation, X-radiation, and electrons. This treatmentis not intended to be exhaustive but reflects special and common terms used in technology andapplication of interest to Committee E61, specifically, terms included in the E61 set of ISO/ASTM andASTM standards on radiation processing.Thi
4、s terminology uses recommended definitions and concepts of quantities, with units, for radiationmeasurements as contained in the International Commisssion on Radiation Units and Measurements(ICRU) Report 85a on “Fundamental Quantities and Units for Ionizing Radiation,” October 2011.2Those terms that
5、 are defined essentially according to the terminology of ICRU Report 85a will befollowed by ICRU in parentheses. It should be noted that the units for quantities used are the latestadopted according to the International System of Units (SI). This terminology also uses recommendeddefinitions of two J
6、CGM documents, namely “International vocabulary of metrology” (VIM 2012)and “Guide to the expression of uncertainty in measurement” (GUM, 2008).3Those terms that aredefined essentially according to the terminology of these documents are followed by either VIM orGUM in parentheses. As far as possible
7、, it is also intended to harmonize the definitions with those inTerminology E170, ISO 11139, and ISO 12749-4.It is recommended that the use of the old units for quantities with special names be avoided;however, if it is deemed necessary to use them for clarity, values of quantities should be express
8、ed firstin the new units followed by values in the old units in parentheses. Table X1.1 summarizes therelationship between the old and new units for the quantities of interest.A term is boldfaced when it is defined in this standard. For some terms, text in italics is used justbefore the definition t
9、o limit its field of application, for example, see activity.1. Scope1.1 This terminology standard lists terms and definitionsrelated to radiation processing concepts, especially radiationdose measurements. Use of this standard, and the commonterminology, will foster clearer communication, and remove
10、ambiguity.1.2 The use of ionizing radiation for the treatment ofcommercial products such as the sterilization of medicaldevices, the reduction of microbial contamination in food orthe modification of polymers is referred to as radiation pro-cessing. The types of radiation used may be gamma radiation
11、(typically from cobalt-60 sources), X-radiation or acceleratedelectrons.1.3 This standard provides terms and definitions for dosim-etry for radiation processing concepts dealing with proceduresrelated to operational qualification, performance qualification,and routine processing that may influence a
12、bsorbed dose in theproducts, and types of dosimetry systems that may be usedduring calibration or on a routine basis as part of qualityassurance in commercial radiation processing of products.1.4 When selecting terms and definitions, special care hasbeen taken to include the terms that need to be de
13、fined, that isto say, either because the definitions are essential to the correctunderstanding of the corresponding concepts or because somespecific ambiguities need to be addressed.1.5 The “Discussion” appended to certain definitions offersclarification or examples to facilitate understanding of th
14、e1This terminology is under the jurisdiction of ASTM Committee E61 onRadiation Processing and is the direct responsibility of Subcommittee E61.91 onTerminology.Current edition approved Oct. 1, 2017. Published November 2017. DOI:10.1520/E3083-172Available from International Commission on Radiation Un
15、its and Measure-ments (ICRU), 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.3Document produced by Working Groups of the Joint Committee for Guides inMetrology (JCGM). Available free of charge at BIPM website (http:/www.bipm.org).Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
16、est Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World
17、Trade Organization Technical Barriers to Trade (TBT) Committee.1concepts described. In certain cases, miscellaneous informationis also included, for example, the units in which a quantity isnormally measured, recommended parameter values,references, etc.1.6 This standard does not purport to address
18、all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed
19、 in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Document
20、s2.1 ASTM Standards:4E170 Terminology Relating to Radiation Measurements andDosimetry2.2 ISO/ASTM Standards:4ISO/ASTM 51649 Practice for Dosimetry in an ElectronBeam Facility for Radiation Processing at Energies Be-tween 300 keV and 25 MeV2.3 Joint Committee for Guides in Metrology (JCGM)Reports:3JC
21、GM 100:2008, GUM 1995, with minor corrections Evalu-ation of measurement data Guide to the expression ofuncertainty in measurementJCGM 200:2012, VIM International vocabulary of metrol-ogy Basic and general concepts and associated terms2.4 ICRU and BIPM Documents:ICRU 85a Fundamental quantities and u
22、nits for ionizingradiation2BIPM The International System of Units (SI)52.5 ISO Standards:612749-4 Nuclear energy, nuclear technologies, and radio-logical protection Vocabulary Part 4: Dosimetry forradiation processingISO/TS 11139 Sterilization of health care products Vo-cabularyISO/IEC 17025 General
23、 requirements for the competence oftesting and calibration laboratories3. Significance and Use3.1 The purpose of this standard is to facilitate communi-cation and promote common understanding within the profes-sionals in radiation processing research and industry.3.2 Unambiguous communication of con
24、cepts is crucialtaking into account the relevant implications that may arisefrom misunderstandings with regard to equipment and materi-als involved in the standards dealing with any subject regardingradiation processing activities. Concepts dealing with dosim-etry related to radiation processing and
25、 procedures forpreparation, testing, and using dosimetry systems to determinethe absorbed dose are present in all standards developed byE61 and ISO/TC85/WG3 and need to be designated bycommon terms and described by harmonized definitions inorder to avoid misunderstandings.4. Terminology4.1 Terms and
26、 Definitions:absorbed dose (D)quotient of dbydm, where d is themean energy imparted by ionizing radiation to matter ofmass dm (ICRU), thusD 5 ddmDISCUSSIONThe SI unit of absorbed dose is the gray (Gy), where 1gray is equivalent to the absorption of 1 joule per kilogram of thespecified material (1 Gy
27、=1 J/kg).absorbed-dose rate (D)quotient of dD by dt, where dD isthe increment of absorbed dose in the time interval dt(ICRU), thusD5 dDdtDISCUSSION(1) The SI unit is Gys-1. However, the absorbed-dose rate is oftenspecified in terms of its average value over longer time intervals, forexample, in unit
28、s of Gymin-1or Gyh-1.(2) In gamma industrial irradiators, dose rate may be significantlydifferent at different locations where product is irradiated.(3) In electron-beam irradiators with pulsed or scanned beam, there aretwo types of dose rate: average value over several pulses (scans) andinstantaneo
29、us value within a pulse (scan). These two values can besignificantly different.absorbed-dose mappingmeasurement of absorbed dosewithin an irradiated product to produce a one-, two-, orthree-dimensional distribution map of absorbed dose.DISCUSSIONFor a process load, such a dose map is obtained usingd
30、osimeters placed at specified locations within the process load.accredited dosimetry calibration laboratorydosimetrylaboratory with formal recognition by an accrediting orga-nization that the dosimetry laboratory is competent to carryout specific activities which lead to calibration or calibra-tion
31、verification of dosimetry systems in accordance withdocumented requirements of the accrediting organization.activity (A)of an amount of radionuclide in a particularenergy state at a given time, quotient of dN by dt, where dNis the mean change in the number of nuclei in that energystate due to sponta
32、neous nuclear transitions in the timeinterval dt (ICRU), thusA 52dNdtUnit: s-1The special name for the unit of activity is becquerel (Bq),thus1Bq=1s-1.DISCUSSION(1) The former special unit of activity was the curie (Ci).1 Ci=3.7 1010s-1.4For referenced ASTM and ISO/ASTM standards, visit the ASTM web
33、site,www.astm.org, or contact ASTM Customer Service at serviceastm.org. ForAnnual Book of ASTM Standards volume information, refer to the standardsDocument Summary page on the ASTM website.5Available in electronic form at www.bipm.org/en/si/si_brochure/6Available from International Organization for
34、Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http:/www.iso.org.E3083 172(2) The particular energy stateis the ground state of the nuclide unlessotherwise specified.(3) The activity of an amount of radionuclide in a particul
35、ar energystate is equal to the product of the decay constant, , for that state andthe number of nuclei in that state (that is A=N).alanine dosimeterspecified quantity and physical form ofthe radiation-sensitive material alanine and any added inertsubstance such as a binder.analysis wavelengthwavelen
36、gth used in a spectrophotomet-ric instrument for the measurement of optical absorbance orreflectance.approved laboratorylaboratory that is a recognized na-tional metrology institute, or has been formally accredited toISO/IEC 17025, or has a quality system consistent with therequirements of ISO/IEC 1
37、7025.DISCUSSION(1) A recognized national metrology institute or other calibrationlaboratory accredited to ISO/IEC 17025 should be used in order toensure traceability to a national or international standard.(2) A calibration certificate provided by a laboratory not having formalrecognition or accredi
38、tation will not necessarily be proof of traceabilityto a national or international standard.beam lengthdimension of the irradiation zone along thedirection of product movement, at a specified distance fromthe accelerator window.DISCUSSION(1) For graphic illustration, see ISO/ASTM 51649.(2) This term
39、 usually applies to electron irradiation.(3) Beam length is therefore perpendicular to beam width and to theelectron beam axis.(4) In case of product that is stationary during irradiation, beam lengthand beam width may be interchangeable.beam widthdimension of the irradiation zone perpendicularto th
40、e direction of product movement, at a specified distancefrom the accelerator window.DISCUSSION(1) For graphic illustration, see ISO/ASTM 51649.(2) This term usually applies to electron irradiation.(3) Beam width is therefore perpendicular to beam length and to theelectron beam axis.(4) In the case o
41、f product that is stationary during irradiation, beamwidth and beam length may be interchangeable.(5) Beam width may be quantified as the distance between two pointsalong the dose profile, which are at a defined fraction of the maximumdose value in the profile.(6) Various techniques may be employed
42、to produce an electron beamwidth adequate to cover the processing zone; for example, use ofelectromagnetic scanning of a pencil beam (in which case beam widthis also referred to as scan width), defocusing elements, and scatteringfoils.bremsstrahlungbroad-spectrum electromagnetic radiationemitted whe
43、n an energetic charged particle is influenced bya strong electric or magnetic field, such as that in the vicinityof an atomic nucleus.DISCUSSION(1) In radiation processing, bremmstrahlung photons with sufficientenergy to cause ionization are generated by the deceleration ordeflection of energetic el
44、ectrons in a target material. When an electronpasses close to an atomic nucleus, the strong coulomb filed causes theelectron to deviate from its original motion. This interaction results ina loss of kinetic energy by the emission of electromagnetic radiation.Since such encounters are uncontrolled, t
45、hey produce a continuousphoton energy distribution that extends up to the maximum kineticenergy of the incident electron.(2) The bremsstrahlung spectrum depends on the electron energy, thecomposition and thickness of the target, and the angle of emission withrespect to the incident electron.calibrat
46、ionset of operations that establish, under specifiedconditions, the relationship between values of quantitiesindicated by a measuring instrument or measuring system, orvalues represented by a material measure or a referencematerial, and the corresponding values realized by standards.DISCUSSIONCalibr
47、ation conditions include environmental and irra-diation conditions present during irradiation, storage and measurementof the dosimeters that are used for the generation of a calibrationcurve.calibration curveexpression of the relation between indica-tion and corresponding measured quantity value (VI
48、M).DISCUSSIONIn radiation processing standards, the term dosimeterresponse is generally used for indication.calorimeterassembly consisting of calorimetric body(absorber), thermal insulation, and temperature sensor withwiring.cellulose triacetate dosimeterpiece of CTA film that,during exposure to ion
49、izing radiation, exhibits a quantifiablechange in specific net absorbance as a function of ab-sorbed dose.ceric-cerous dosimeterspecially prepared solution of cericsulfate and cerous sulfate in sulfuric acid, individually sealedin an appropriate container such as a glass ampoule, wherethe radiation-induced changes in electropotential or opticalabsorbance of the solution is related to absorbed dose towater.charged-particle equilibrium (referred to as electron equilib-rium in the case of electrons set in motion by p
