1、Designation: E 2303 03An American National StandardStandard Guide forAbsorbed-Dose Mapping in Radiation Processing Facilities1This standard is issued under the fixed designation E 2303; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 document provides guidance in determiningabsorbed-dose distributions in products, materials or su
3、b-stances irradiated in gamma, X-ray (bremsstrahlung) andelectron beam facilities.NOTE 1For irradiation of food and the radiation sterilization of healthcare products, other specific ISO and ISO/ASTM standards containingdose mapping requirements exist. For food irradiation, see ISO/ASTM51204, Practi
4、ce for Dosimetry in Gamma Irradiation Facilities for FoodProcessing and ISO/ASTM 51431, Practice for Dosimetry in Electron andBremsstrahlung Irradiation Facilities for Food Processing. For the radia-tion sterilization of health care products, see ISO 11137: 1995, Steriliza-tion of Health Care Produc
5、ts Requirements for Validation and RoutineControl Radiation Sterilization. In those areas covered by ISO 11137, thatstandard takes precedence. ISO/ASTM Practice 51608, ISO/ASTM Prac-tice 51649, and ISO/ASTM Practice 51702 also contain dose mappingrequirements.1.2 Methods of analyzing the dose map da
6、ta are described.Examples are provided of statistical methods that may be usedto analyze dose map data.1.3 Dose mapping for bulk flow processing and fluidstreams is not discussed.1.4 Dosimetry is only one component of a total qualityprogram for an irradiation facility. Other controls besidesdosimetr
7、y may be required for specific applications such asmedical device sterilization and food preservation.1.5 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 and he
8、alth practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:E 170 Terminology Relating to Radiation Measurementsand Dosimetry2E 177 Practice for the Use of the Terms Precision andAccuracy Applied to Measurement of a Property of Ma
9、te-rial3E 178 Practice for Dealing with Outlying Observations3E 666 Practice for Calculating Absorbed Dose from Gammaor X Radiation2E 668 Practice for the Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining Absorbed Dosein Radiation-Hardness Testing of Electronic Devices2E 1026
10、 Practice for Using the Fricke Reference StandardDosimetry System2E 2232 Guide for Selection and Use of Mathematical Meth-ods for Calculating Absorbed Dose in Radiation ProcessingApplications22.2 ISO/ASTM Standards:4ISO/ASTM 51204 Practice for Dosimetry in Gamma Irra-diation Facilities for Food Proc
11、essingISO/ASTM 51205 Practice for Use of a Ceric-Cerous Sul-fate Dosimetry SystemISO/ASTM 51261 Guide for Selection and Calibration ofDosimetry Systems for Radiation ProcessingISO/ASTM 51275 Practice for Use of a Radiochromic FilmDosimetry SystemISO/ASTM 51276 Practice for Use of a Polymethyl-methac
12、rylate Dosimetry SystemISO/ASTM 51310 Practice for Use of a RadiochromicOptical Waveguide Dosimetry SystemISO/ASTM 51400 Practice for Characterization and Perfor-mance of a High-Dose Radiation Dosimetry CalibrationLaboratoryISO/ASTM 51401 Practice for Use of a Dichromate Dosim-etry SystemISO/ASTM 51
13、431 Practice for Dosimetry in Electron andBremsstrahlung Irradiation Facilities for Food ProcessingISO/ASTM 51538 Practice for Use of the Ethanol-Chlorobenzene Dosimetry SystemISO/ASTM 51540 Practice for Use of a RadiochromicLiquid Dosimetry SystemISO/ASTM 51607 Practice for Use of the Alanine-EPRDo
14、simetry System1This guide is under the jurisdiction of ASTM Committee E10 on NuclearTechnology and Application and is the direct responsibility of Subcommittee E10.01on Dosimetry for Radiation Processing.Current edition approved July 10, 2003. Published August 20032Annual Book of ASTM Standards, Vol
15、 12.02.3Annual Book of ASTM Standards, Vol 14.02.4Standards on Dosimetry for Radiation Processing ASTM International 2002.See Annual Book of ASTM Standards, Vol 12.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ISO/ASTM 51608 Pra
16、ctice for Dosimetry in an X-ray(Bremsstrahlung) Facility for Radiation ProcessingISO/ASTM 51631 Practice for Use of Calorimetric Dosim-etry Systems for Electron Beam Dose Measurements andDosimeter CalibrationsISO/ASTM 51649 Practice for Dosimetry in an Electronbeam Facility for Radiation Processing
17、at Energies be-tween 300 keV and 25 MeVISO/ASTM 51650 Practice for Use of Cellulose AcetateDosimetry SystemsISO/ASTM 51702 Practice for Dosimetry in a GammaIrradiation Facility for Radiation ProcessingISO/ASTM 51707 Guide for Estimating Uncertainties inDosimetry for Radiation ProcessingISO/ASTM 5181
18、8 Practice for Dosimetry in an ElectronBeam Facility for Radiation Processing at Energies be-tween 80 and 300 keV2.3 International Commission on Radiation Units andMeasurements Reports:5ICRU Report 14 Radiation Dosimetry: X-Rays and GammaRays with Maximum Photon Energies Between 0.6 and 50MeVICRU Re
19、port 17 Radiation Dosimetry: X-Rays Generated atPotentials of 5 to 150 kVICRU Report 34 The Dosimetry of Pulsed RadiationICRU Report 35 Radiation Dosimetry: Electron Beams withEnergies Between 1 and 50 MeVICRU Report 37 Stopping Powers for Electrons andPositronsICRU Report 60 Fundamental Quantities
20、and Units forIonizing Radiation2.4 International Organization for Standardization:6ISO 11137 Sterilization of Health Care ProductsRequirements for Validation and Routine ControlRadiation Sterilization3. Terminology3.1 Definitions:3.1.1 absorbed-dose mapping measurement of absorbeddose within a proce
21、ss load using dosimeters placed at specifiedlocations to produce a one, two or three-dimensional distribu-tion of absorbed dose, thus rendering a map of absorbed-dosevalues.3.1.2 calibration curvegraphical representation of thedosimetry systems response function.3.1.3 containercarrier, tote, cart, t
22、ray or other container inwhich product is loaded to traverse the irradiation field. Insome instances, this may be the actual product package.3.1.4 dose map, dose mappingSee absorbed-dose map-ping.3.1.5 dose uniformity ratioratio of the maximum to theminimum absorbed dose within a process load. The c
23、oncept isalso referred to as the max/min dose ratio.3.1.6 dose zonea volume or discrete point(s) within aprocess load that receives the same absorbed dose within thestatistical uncertainty of the irradiation process and absorbeddose measurement(s).3.1.7 installation qualification (IQ)obtaining and d
24、ocu-menting evidence that equipment has been provided andinstalled in accordance with its specification.3.1.8 operational qualification (OQ)obtaining and docu-menting evidence that installed equipment operates withinpredetermined limits when used in accordance with its opera-tional procedures.3.1.9
25、performance qualification (PQ)obtaining and docu-menting evidence that the equipment, as installed and operatedin accordance with operational procedures, consistently per-forms in accordance with predetermined criteria and therebyyields product meeting its specification.3.1.10 process loada volume o
26、f material with a specifiedloading configuration irradiated as a single entity.3.1.11 reference positiondose measurement position withan established relationship to the minimum and/or maximumdose zones.3.1.12 simulated productmaterial with attenuation andscattering properties similar to those of the
27、 product, material orsubstance to be irradiated.3.1.12.1 DiscussionSimulated product may be used dur-ing operational qualification as a substitute for the actualproduct, material or substance to be irradiated. When used inroutine production runs, it is sometimes referred to as compen-sating dummy. W
28、hen used for absorbed-dose mapping, simu-lated product is sometimes referred to as phantom material.3.2 Definitions of other terms used in this standard thatpertain to radiation measurement and dosimetry may be foundin Terminology E 170. Definitions in E 170 are compatiblewith ICRU 60; that document
29、, therefore, may be used as analternative reference.4. Significance and Use4.1 Radiation processing is carried out under fixed pathconditions where (a) a process load is automatically movedthrough the radiation field by mechanical means or (b)aprocess load is irradiated statically by manually placin
30、g prod-uct at predetermined positions before the process is started. Inboth cases the process is controlled in such a manner that theprocess load position(s) and orientation(s) are reproduciblewithin specified limits.4.2 Some radiation processing facilities that utilize a fixedconveyor path for rout
31、ine processing may also characterize aregion within the radiation field for static radiation processing,sometimes referred to as “Off Carrier” processing.4.3 Radiation processing may require a minimum absorbeddose (to achieve a desired effect or to fulfill a legal require-ment), and a maximum dose t
32、hat can be tolerated (while theproduct, material or substance still meets functional specifica-tions or to fulfill a legal requirement).4.4 Dose mapping is used to characterize the radiationprocess and assess the reproducibility of absorbed-dose results,which may be used as part of operational quali
33、fication andperformance qualification.5Available from International Commission on Radiation Units and Measure-ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.6Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerlan
34、d.E23030324.5 Dose mapping is used to determine the spatial distribu-tion of absorbed doses and the zone(s) of maximum andminimum absorbed doses throughout a process load, whichmay consist of an actual or simulated product.4.6 Dose mapping is used to establish the relationshipbetween the dose at a r
35、eference position and the dose within theminimum and maximum dose zones established for a processload.4.7 Dose mapping is used to verify mathematical dosecalculation methods. See Guide E 2232.4.8 Dose mapping is used to determine the process shut-down and startup transit dose effect on the distribut
36、ion ofabsorbed dose and the magnitude of the minimum and maxi-mum doses.4.9 Dose mapping is used to assess the impact on thedistribution of absorbed dose and the magnitude of the mini-mum and maximum doses resulting from the transition fromone process load to another where changes, for example, inde
37、nsity or product loading pattern may occur.5. Prerequisites5.1 Installation Qualification, Dosimetry and Other Prereq-uisites to Dose Mapping:5.1.1 Prior to performing the irradiator operational qualifi-cation (OQ) and performance qualification (PQ) dose mapping,confirm that installation qualificati
38、on (IQ) is complete.5.1.2 Select an appropriate dosimetry system(s) for the dosemapping experiments. See ISO/ASTM Guide 51261 for guid-ance.NOTE 2For requirements on the qualification of equipment andcontrol systems, refer to ISO/ASTM Standard Practices 51204, 51431,51608, 51649, 51702, and ISO 1113
39、7.5.2 Calibration of the Dosimetry System:5.2.1 Prior to use, the dosimetry system (consisting of aspecific batch of dosimeters and specific measurement instru-ments) shall be calibrated in accordance with the usersdocumented procedure that specifies details of the calibrationprocess and quality ass
40、urance requirements. This calibrationprocess shall be repeated at regular intervals to ensure that theaccuracy of the absorbed-dose measurement is maintainedwithin required limits. Calibration methods are described inISO/ASTM Guide 51261.5.3 Calibration Irradiation of DosimetersIrradiation is acriti
41、cal component of the calibration of the dosimetry system.Calibration irradiations shall be performed in one of three waysby irradiating the dosimeters at:5.3.1 An accredited calibration laboratory that provides anabsorbed dose (or an absorbed-dose rate) having measurementtraceability to nationally o
42、r internationally recognized stan-dards, or5.3.2 An in-house calibration facility that provides an ab-sorbed dose (or an absorbed-dose rate) having measurementtraceability to nationally or internationally recognized stan-dards, or5.3.3 A production or research irradiation facility togetherwith refer
43、ence- or transfer-standard dosimeters that have mea-surement traceability to nationally or internationally recog-nized standards.5.4 Measurement Instrument Calibration and PerformanceVerificationFor the calibration of the instruments, and for theverification of instrument performance between calibra
44、tions,see ISO/ASTM Guide 51261 and/or instrument-specific oper-ating manuals.6. Dose Mapping6.1 Dose Mapping for Operational Qualification of theIrradiation Facility:6.1.1 As specified in Practices ISO/ASTM 51204, ISO/ASTM 51431, ISO/ASTM 51608, ISO/ASTM 51649, ISO/ASTM 51702 and ISO 11137, perform
45、irradiation facility dosemapping to characterize the irradiator with respect to the dosedistribution and reproducibility of absorbed dose delivery. Thisshould be performed in accordance with a formal validationprogram over the operational range that will be used in theirradiation of products.6.1.2 P
46、erform irradiation facility dose mapping by placingdosimeters in a process load of homogeneous density materialthat fills the container to its design volume limits. Materialdensities should be within the density range for which theirradiator is to be used. In electron beam facilities, a singlemateri
47、al density may be used provided the maximum andminimum process settings that affect dose are demonstrated(for example, conveyor speed, beam current, scan frequencyand scan height or width). Determine absorbed dose distribu-tion throughout the process load for each product path throughthe irradiation
48、 field.DiscussionElectron beam irradiation facilities may satisfythe dose mapping requirements described in 6.1.2 using a twodimensional surface grid dose map with a separate penetrationtest performed in a homogenous density material. Appropriatemethods should be used (see ISO/ASTM Practice 51649) t
49、odetermine the electron beam energy. For process load fringe oredge effect studies in electron beam, several different densitiesof homogeneous material should be used. The maximumelectron beam process area limits may be determined bydemonstrating the uniformity of absorbed dose in both thedirection of scan and direction of travel under the maximumand minimum process settings that affect dose (for example,conveyor speed, beam current, scan frequency and scan heightor width). Different product paths through the radiation processfield need not be a physical transport p
