ASTM_D_3001_-_71_1984_scan.pdf

W 900927b 0009537 989 AMERICAN ANSVASTM D 3001-71(Reapproved 1977)Giza REAPPROVED 84 Standard Test Method for ABSORBED GAMMA AND ELECTRON RADIATION DOSE WITH THE CERIC SULFATE DOSIMETER This Standard is issued under the fixed designation D 3001;the number immediately following the designation indicates the year or original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year o last reapproval.1.Scope I.I This method covers the preparation and procedure for the use of the ceric sulfate do-simeter.1.2 Ceric sulfate dosimetry is used for ac-curate measurement of the absorbed dose in water irradiated with X or gamma rays or high-energy electrons.It is based on the process of reduction of ceric to cerous ions by ionizing radiation.The method is most accu-rate for absorbed doses in the range from 1 x 10 to 8 x IO6 rd,using spectrophotometric measurement of the ceric ion concentration.2.Summary of Method 2.1 The change in absorbance(at a given wavelength)after irradiation of a solution of ceric ammonium sulfate is measured spectro-photometrically.Since the absorbed dose in the solution is proportional to the change in absorbance(optical density),the dose can be determined by multiplying the change in ab-sorbance by a suitable conversion factor.3.Significance 3.1 Absorbed Dose-This dosimeter pro-vides a means for measuring the radiation dose absorbed in a solution that is equivalent to the dose absorbed in water.To convert to the absorbed photon dose in other materials the procedures of ASTM Recommended Practice D 2568,Calculation of Absorbed Dose from X or Gamma Radiation,should be used.3.2 Dose Rote-No effect on accuracy or measurement of radiation dose is observed with dose rates between 20 rd/s and 108rd/s(100 rd/pulse).3.3 Temperature-The reliability of the method is not significantly influenced by a variation of the temperature of the system between 15 and 30 C during irradiation.However,at temperatures above 30 C the G-value decreases as the temperature increases leading to erroneously low values for ab-sorbed dose.3.4 Energy Dependence-The response of this system(here defined as change in absorb-ance per unit absorbed dose in solution),has been shown to be independent of photon en-ergy in the range of 0.1 to IO MeV.4.Definitions 4.1 rod-the recommended unit for re-porting absorbed radiation dose:it is defined as 100 ergs of energy absorbed per gram of specimen.5.Interferences 5.1 The use of organic stoppers,organic tubing,or metal tubing for sealing or transfer-ring any of the solutions should be avoided,since contact between the solutions and any organic material or metals can lead to erratic results.This system is extremely sensitive to organic impurities even in trace quantities.5.2 Glassware should be kept extremely clean.6.Apparatus 6.1 Spectrophotometer-Beckman Model DU,hydrogen lamp attachment,and I-cm matched quartz cells,or equivalent apparatus equipped with a temperature-controlled cell compartment should be used for absorbance measurements.6.2 Containers:6.2.1 Chemically resistant borosilicate glass 6.2.2 Irradiation containers for the dosim-should be used to hold the reagents.This method is under the jurisdiction of ASTM Committee E-IO on Nuclear Applications and Measurement of Radiation Effecis.r-b.,31.Effective Dec.22,1971.L 134 NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.9007276 0009538 AL5 etry solution should have approximately the same dimensions and geometry as those em-ployed to hold the specimens for irradiation.If the specimen containers are metal or or-ganic,a thin-walled glass liner,1.0 to 1.2 mm in maximum thickness,should be used inside the container(5-ml,quick-break,sealed-glass ampoules or equivalent containers are recom-mended).The inside diameter of the con-tainers should not be less than 8 mm.6.2.3 Dosimetry containers and other glass-ware may be cleaned by filling them with ceric ammonium sulfate solution,irradiating them to a dose lo6 rd,and then rinsing thoroughly(three times)with fresh dosimetry solution.7.Reagents 7.1 Purity of Reagents-Reagent grade chemicals shall be used in all tests.Unless otherwise indicated,it is intended that all re-agents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society,where such speci-fications are available.2 Other grades may be used,provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.7.2 Purity of Water-Distilled water used in this method shall be free of organic impuri-ties.Use triply distilled water for all dosim-etry solutions if possible.Deionized water or commercially available singly distilled water is not acceptable for use with this method.7.3 Dosimetry Soluiion:7.3.1 Dosimetry Stock Solution(0.1 N Ceric Ammonium