ASTM_C_982_-_03.pdf

Designation:C 982 03Standard Guide for Selecting Components forEnergy-Dispersive X-Ray Fluorescence(XRF)Systems1This standard is issued under the fixed designation C 982;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide describes the components for an energy-dispersive X-ray fluorescence(XRF)system for materialsanalysis.It can be used as a reference in the apparatus sectionof test methods for energy-dispersive X-ray fluorescenceanalyses of nuclear materials.1.2 The components recommended include X-ray detectors,signal processing electronics,data acquisition and analysissystems,and excitation sources that emit photons(See Fig.1).1.3 Detailed data analysis methods are not described orrecommended,as they may be unique to a particular analysisproblem.Some applications may require the use of spectrumdeconvolution to separate partially resolved peaks or to correctfor matrix effects in data reduction.1.4 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 Documents2.1 ASTM Standards:E 135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related Materials2E 181 General Methods for Detector Calibration andAnaly-sis of Radionuclides32.2Other Document:ANSI/HPS N43.22001 Radiation Safety for X-Ray Dif-fraction and Fluorescence Analysis Equipment43.Significance and Use3.1 This guide describes typical prospective analyticalX-ray fluorescence systems that may be used for qualitativeand quantitative elemental analysis of materials related to thenuclear fuel cycle.3.2 Standard methods for the determination of materialsusing energy-dispersive XRF5usually employ apparatus withthe components described in this document.4.Hazards4.1 XRF equipment analyzes by the interaction of ionizingradiation with the sample.Applicable safety regulation andstandard operating procedures must be reviewed prior to theuse of such equipment.(See ANSI/HPS N43.2.)4.2 Instrument performance may be influenced by environ-mental factors such as heat,vibration,humidity,dust,strayelectronic noise,and line voltage stability.These factors andperformance criteria should be reviewed with equipmentmanufacturers.4.3 The quality of quantitative XRF results can be depen-dent on a variety of factors,such as sample preparation andmounting.Consult the specific analysis method for recom-mended procedures.4.4 Sample chambers are available commercially for opera-tion in air,vacuum,or helium atmospheres,depending uponthe elements to be determined and the physical form of thesample.5.Energy Dispersive X-Ray DetectorsNOTE1Because of the rapid improvement in detector and electronicstechnologies,the most up-to-date information on XRF components isfound in manufacturers literature.Lists of vendors of XRF equipment canbe found in compilations such as the“Guide to Scientific Instruments,”published by the American Association for the Advancement of Science,Washington,DC.5.1 Energy-dispersive X-ray detectors can be used to detectX rays with energies from approximately 1 to 100 keV;however,a single-type detector usually cannot satisfy all therequirements of efficiency and energy resolution over such awide energy range.1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved July 10,2003.Published September 2003.Originallyapproved in 1988.Last previous edition aproved in 1997 as C 98288(1997)e12Annual Book of ASTM Standards,Vol 03.05.3Annual Book of ASTM Standards,Vol 12.02.4Available from American National Standards Institute,Inc.or the HealthPhysics Society.5General References for XRF include Bertin,Eugene P.,Principles andPractices of X-Ray Spectrometric Analysis,Second Ed.,Plenum Press,NewYork-London,1975,Jenkins,Ron,An Introduction to X-Ray Spectrometry,Heydenand Sons,Ltd.,London,New York,Rhine,1974,and Woldseth,Rolf,All You EverWanted to Know About X-Ray Energy Spectrometry,First Ed.,Kevex Corporation,Burlingame,CA,1973.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.5.2 The energy resolution(Terminology E 135)of a detectoris usually specified by the FWHM(full width at half maxi-mum)of the full energy peak of an X ray(or g ray)of aparticular energy and at a specified count rate.The FWTM(fullwidth at one-tenth maximum)of the full-energy peak or thepeak-to-background ratio,or both,may also be specified.“High resolution”(small values of FWHM)detectors arerequired to separate X rays of s