ASTM_E_181_-_10.pdf

Designation:E18110Standard Test Methods forDetector Calibration and Analysis of Radionuclides1This standard is issued under the fixed designation E181;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 indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1These methods cover general procedures for the cali-bration of radiation detectors and the analysis of radionuclides.For each individual radionuclide,one or more of these methodsmay apply.1.2 These methods are concerned only with specific radio-nuclide measurements.The chemical and physical propertiesof the radionuclides are not within the scope of this standard.1.3 The measurement standards appear in the followingorder:SectionsSpectroscopy Methods:Calibration and Usage of Germa-nium Detectors3 12Calibration and Usage of ScintillationDetector Systems:13 20Calibration and Usage of ScintillationDetectors for Simple Spectra16Calibration and Usage of ScintillationDetectors for Complex Spectra17SectionsCounting Methods:Beta Particle Counting25-26Aluminum Absorption Curve27 31Alpha Particle Counting32 39Liquid Scintillation Counting40 481.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Document2.1 ASTM Standards:2E170 Terminology Relating to Radiation Measurements andDosimetrySPECTROSCOPY METHODS3.Terminology3.1 Definitions:3.1.1 certified radioactivity standard sourcea calibratedradioactive source,with stated accuracy,whose calibration iscertified by the source supplier as traceable to the NationalRadioactivity Measurements System(1).33.1.2 check sourcea radioactivity source,not necessarilycalibrated,that is used to confirm the continuing satisfactoryoperation of an instrument.3.1.3 FWHM(full width at half maximum)the full widthof a gamma-ray peak distribution measured at half the maxi-mum ordinate above the continuum.3.1.4 national radioactivity standard sourcea calibratedradioactive source prepared and distributed as a standardreference material by the U.S.National Institute of Standardsand Technology.3.1.5 resolution,gamma raythe measured FWHM,afterbackground subtraction,of a gamma-ray peak distribution,expressed in units of energy.3.2 Abbreviations:3.2.1 MCAMultichannel Analyzer.3.2.2 SCASingle Channel Analyzer.3.2.3 ROIRegion-Of-Interest.3.3 For other relevant terms,see Terminology E170.1These methods are under the jurisdiction of ASTM Committee E10 on NuclearTechnology and Applications.Current edition approved Jan.1,2010.Published February 2010.Originallyapproved in 1961.Last previous edition approved in 2003 as E181 98(2003).DOI:10.1520/E0181-10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to the list of references at the end ofthese methods.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.4 correlated photon summingthe simultaneous detectionof two or more photons originating from a single nucleardisintegration.3.5 dead timethe time after a triggering pulse duringwhich the system is unable to retrigger.NOTE1The terms“standard source”and“radioactivity standard”aregeneral terms used to refer to the sources and standards of NationalRadioactivity Standard Source and Certified Radioactivity StandardSource.CALIBRATION AND USAGE OF GERMANIUMDETECTORS4.Scope4.1 This standard establishes methods for calibration,usage,and performance testing of germanium detectors for themeasurement of gamma-ray emission rates of radionuclides.Itcovers the energy and full-energy peak efficiency calibration aswell as the determination of gamma-ray energies in the 0.06 to2-MeV energy region and is designed to yield gamma-rayemission rates with an uncertainty of 63%(see Note 2).Thismethod applies primarily to measurements that do not involveoverlapping peaks,and in which peak-to-continuum consider-ations are not important.NOTE2Uncertainty U is given at the 68%confidence level;that is,U5=(i211/3(i2where iare the estimated maximum systematicuncertainties,and iare the random uncertainties at the 68%confidencelevel(2).Other methods of error analysis are in use(3,4).5.Apparatus5.1 A typical gamma-ray spectrometry system consists of agermanium detector(with its liquid nitrogen cryostat,preamplifier,and possibly a high-voltage filter)in conjuncti