1、Designation: D7902 18Standard Terminology forRadiochemical Analyses1This standard is issued under the fixed designation D7902; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indic
2、ates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard describes terminology commonly used inradiochemistry and radioanalysis.1.2 The values stated in SI units are to be regarded asstandard. Other units
3、of measurement, including some unitsthat are not accepted for use with the SI, are also defined.1.3 This standard does not purport to address 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
4、 environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International S
5、tandards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D7282 Practice for Set-up, Calibration, and Quality Controlof Instruments Used for Radioactivity Measurements2.2 BIPM Documents:3GUM Guid
6、e to the Expression of Uncertainty in Measure-ment (GUM), 100:20082.3 Code of Federal Regulations:440 CFR 141.25 Analytical Methods for Radioactivity40 CFR Appendix B to Part 136 Definition and Procedurefor the Determination of the Method Detection Limit2.4 ANSI Documents:5ANSI N42.22 Traceability o
7、f Radioactive Sources to theNational Institute of Standards and Technology (NIST)and Associated Instrument Quality Control3. Significance and Use3.1 This terminology standard describes terms and defini-tions used in standards for radiochemical analysis maintainedby ASTM Committee D19 on Water. The t
8、erminology is alsorecommended for general use in the radiochemistry commu-nity.4. Terminology: Terms and Definitions4 geometry, ngeometry in which the radiation detector hasessentially the same probability of detecting radiation fromthe source emitted in any direction.absorption (of radiation), ntra
9、nsfer of some or all of theenergy of a radiation to matter it traverses.abundance, (1) nprobability of emission of a given radiationduring the decay of an atom of a given radionuclide;radiation emission probabilityalso called intensity;(2) see isotopic abundance.actinide, nany element with atomic nu
10、mber between 89 and103, including actinium, thorium, protactinium, uranium,neptunium, plutonium, americium, and curium.activation, ninducement of radioactivity by irradiation.activation analysis, nanalysis based on the characteristicradiations emitted by nuclides formed by activation.activity (for r
11、adionuclides), A T1, nmean rate of radio-active decay in a quantity of material.DISCUSSIONThe term activity may be qualified by specifying one ormore radionuclides (for example,238U activity) or the type of decay(for example, gross alpha activity).DISCUSSIONThe SI unit of activity is the becquerel (
12、Bq), whichequals 1 s1(one nuclear disintegration per second).activity concentration, (1) nquotient of the activity of aspecified quantity of material and its volume; volumic1This terminology is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.
13、04 on Methods of Radiochemi-cal Analysis.Current edition approved Feb. 1, 2018. Published March 2018. Originallyapproved in 2014. Last previous edition approved in 2016 as D7902 16. DOI:10.1520/D7902-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Ser
14、vice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Bureau International des Poids et Mesures (BIPM), Pavillon deBreteuil F-92312 Svres Cedex, France, http:/www.bipm.org.4Available from U.S. Gov
15、ernment Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West 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 Rec
17、ommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1activity;(2) nquotient of the activity of a specified quantity ofmaterial and its associated mass or size.aliquant, nfractional part that does not evenly divide thewhole.aliquot, nfractional part that ev
18、enly divides the whole.DISCUSSIONChemists commonly use the term aliquot to mean eitheran aliquant or aliquot of a sample.alpha decay, nradioactive decay accompanied by the emis-sion of an alpha particle.alpha particle, particle, nparticle consisting of twoprotons and two neutrons (a4He nucleus) emit
19、ted from anucleus during certain types of radioactive decay.alpha-particle spectrometry, alpha spectrometry,nmeasurement of components of a sample or system basedon analysis of alpha-particle spectra.DISCUSSIONIn titles and summaries, the full name alpha-particlespectrometry is preferred. In other c
20、ontexts, either name is oftenacceptable.alpha scintillation cell, nspecially designed sealablecontainer, whose walls are coated with silver-activated zincsulfide (a scintillator), having a transparent window at oneend, which can be filled with a gas such as helium ornitrogen containing some quantity
21、 of radon and used inconjunction with a scintillation counter to measure the alphaemissions of the radon and its progeny.analyst, nperson who performs analyses.analyte, nin an analysis, the component analyzed for.ancestor (radionuclide), parent (radionuclide),nradionuclide that produces a given nucl
22、ide in a series ofone or more radioactive decays.DISCUSSIONThe term ancestor is often used in the context ofindirect relationships involving a series of decays. The term parent isoften used when there is a direct relationship.annihilation, ninteraction between a particle and its antipar-ticle in whi
23、ch the original particles disappear and newphotons or particles are produced.annihilation peak, npeak in a gamma-ray spectrum at511 keV produced by annihilations of positrons and elec-trons.DISCUSSIONEach annihilation results in two 511 keV gamma-rays,at least one of which usually escapes from the d
24、etector withoutdepositing its energy.anticoincidence counting, nradiometric counting techniquethat lowers interference levels by rejecting any event that isaccompanied by one or more other events occurring withina specified time interval.DISCUSSIONAnticoincidence counting requires two or moredetecto
25、rs, often of different types, operating simultaneously.areic, adjin proportion to area.DISCUSSIONThe adjective areic, when applied to the name of ameasurable quantity, indicates the quotient of that quantity and itsassociated area, as in areic activity or areic mass.attenuation (of radiation), ndecr
26、ease in intensity of radia-tion due to interactions with matter.attenuation coefficient, linear attenuation coefficient, or lL1, nfor a parallel beam of photons passing through amaterial, the fraction of the photons removed in a shortdistance, divided by that distance (see also mass attenua-tion coe
27、fficient).DISCUSSIONThe concept of an attenuation coeffcient may beapplied to other types of radiation provided the attenuation followsapproximately an exponential law.attenuation curve, nplot of attenuation factors versus an-other quantity such as distance, mass, or areic mass.attenuation factor, n
28、fraction of a beam of radiation remain-ing after the beam has passed through a given amount ofmaterial.Auger effect, nejection of an electron, called an Augerelectron, from an outer shell, accompanying the filling of avacancy in an inner shell.DISCUSSIONThe Auger effect and X-ray emission are altern
29、ativemeans of releasing energy when such an inner shell vacancy is filled.Auger electron, norbital electron ejected from an atom inthe Auger effect.background, (1) nin general, the normal analyteconcentration, radiation level, or instrument signal observedin the absence of the analyte or in the abse
30、nce of any analytecontributed by a given cause;(2) ninstrument signal observed in the absence of asource (also instrument background or detector back-ground).DISCUSSIONThe unqualified term background has so many shadesof meaning that it can be a source of confusion unless it is explained.background
31、subtraction count, BSC, na source count usedto determine the background to be subtracted from thesample test source count. D7282backscatter(ing), ndeflection of radiation by matter at anyangle greater than 90 from its original direction of motion.backscatter peak, npeak in a gamma-ray spectrum pro-d
32、uced by photons resulting from Compton scattering in thematerial surrounding the detector.baseline, nin the graph of a spectrum, the straight or curvingline on which peaks are superimposed.becquerel, Bq, nspecial name for the SI derived unit ofactivity, equal to 1 s1(one nuclear disintegration perse
33、cond).beta decay, decay, nradioactive decay that results in achange in atomic number but no change in mass number; decay, +decay, or electron capture.decay, nradioactive decay accompanied by the emissionof a particle and an antineutrino.+decay, nradioactive decay accompanied by the emissionof a +par
34、ticle and a neutrino.D7902 182beta particle, particle, nelectron () or positron (+)emitted from a nucleus during certain types of radioactivedecay.bias (voltage), nfor many types of radiation detector, avoltage applied to the detector to enable it to detect anionizing event.blank, (1) adjcontaining
35、little or no analyte; analyte-free;(2) see blank sample.blank sample, nany of various types of real or artificialsamples that are expected to contain little or no analyte, suchas a method blank or reagent blank.DISCUSSIONUse of the term blank sample without qualification orexplanation may cause conf
36、usion.blank source, nsource prepared to simulate a test sourcewith no analyte present.branching decay, nradioactive decay that can proceed inmore than one way.branching fraction, branching ratio, nin branching decay,the fraction of nuclei that decay in a specified way.calibration source, CS, na know
37、n quantity of radioactivematerial, traceable to a national standards body, prepared forthe purpose of calibrating nuclear instruments. D7282carrier, nan isotope or mixture of isotopes of an element,chemically identical or similar to the radionuclide(s) ofinterest, added in a quantity sufficient to p
38、romote a desiredchemical behavior and move the radionuclide(s) or anunwanted contaminant through a chemical process.DISCUSSIONIn radiochemistry the use of a carrier may also allowgravimetric measurement of the chemical yield.cascade summing, (true) coincidence summing,nsumming produced when the ener
39、gies of two or moreradiations emitted by the same atom are absorbed by thedetector within a period of time shorter than the resolvingtime of the detector.erenkov counting, nradiation counting technique based ondetection of erenkov radiation (also Cerenkov or Cheren-kov).erenkov radiation, nelectroma
40、gnetic radiation emitted bya charged particle moving through a medium at a speedgreater than the speed of light in that medium (also Cerenkovor Cherenkov).channel, nany of the data registers or memory locations usedto record pulses in a single-channel or multichannel ana-lyzer.chemical yield, nfract
41、ion of the amount of a given analyte orother substance remaining after specified chemical separa-tions (sometimes called recovery or chemical recovery).DISCUSSIONUse of the term recovery as a synonym for chemicalyield may cause confusion and should be avoided. See recovery.chemiluminescence, nemissi
42、on of electromagnetic radiationas a result of a chemical reaction a possible cause ofinterference in liquid scintillation counting.coincidence counting, nradiometric counting technique thatlowers interferences by rejecting any event that is notaccompanied by one or more other events occurring within
43、a specified time interval; for example, coincidence countingof the beta particle and 364.5 keV gamma-ray from thedecay of131I.DISCUSSIONCoincidence counting requires two or more detectors,often of different types, operating bined standard uncertainty, uc, nstandard uncertaintyof a measurement result
44、 obtained by uncertainty propaga-tion.Compton baseline, nbaseline in a gamma-ray spectrum,which is due largely to Compton scattering but also in partto tailing and other effects.Compton edge, nfeature of a gamma-ray spectrum whichappears as an abrupt decrease in the baseline at the upper endof the e
45、nergy distribution of the Compton electrons associ-ated with a gamma-ray photopeak.DISCUSSIONThe Compton edge is found at the energyE2 E1 mec22!where Eis the energy of the photopeak.Compton effect, Compton scattering, nscattering of aphoton by a free or weakly bound electron in which theincident pho
46、ton imparts a portion of its energy and momen-tum to the electron, resulting in a free electron and ascattered lower-energy photon.Compton electron, nthe energetic free electron resultingfrom the Compton effect.Compton photon, nthe scattered photon resulting from theCompton effect.conversion electro
47、n, nthe orbital electron ejected from anatom by internal conversion.coprecipitation, nprecipitation of a normally soluble com-ponent by inclusion in the precipitate of another less solublecomponent from the same solution.cosmic radiation, nradiation that originates outside Earthsatmosphere.count, (1
48、) vto perform a radiation counting measurement;(2) na radiation counting measurement;(3) na single pulse registered during counting;(4) ntotal number of pulses registered during counting.counting effciencysee detection efficiency.counting period, counting interval, ntime interval from thebeginning t
49、o the end of a radiation counting measurement.counting uncertainty, nin radiochemistry, the uncertainty ofthe result of a measurement due to the random nature ofradioactive decay, radiation emission, and radiationdetectionalso called counting error.DISCUSSIONThe term counting uncertainty is preferred because ofthe emphasis in metrology on the distinction between error of mea-surement and uncertainty of measurement.D7902 183coun
