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ASTM ISO/ASTM51900-23 Standard Guidance for Dosimetry for Radiation Research Active 发布日期 :  1970-01-01 实施日期 : 

4.1 Reliable dosimetry is indispensable for research on the effects of ionizing radiation on materials and products. Without reliable dosimetry valid conclusions cannot be reached, or the wrong conclusions might be reached.4.2 This document is intended to provide direction on how to conduct dosimetry for research and experiments on the effects of ionizing radiation on materials and products, and on the reporting of dosimetry results. Requirements on dosimetry and on dose ranges might differ between the various types of experiments to be carried out.4.3 Proper reporting of the manner in which the irradiation was carried out is important since the degree of radiation effect might be a function of various factors, other than absorbed dose, such as the radiation source, the absorbed-dose rate, energy of the incident radiation, ambient environmental conditions during irradiation, and the type of incident radiation. This document attempts to highlight the information, including the methodology and results of the absorbed-dose measurements, necessary for an experiment to be repeatable by other researchers.4.4 In most cases an experiment should be designed to irradiate the sample as uniformly as possible. In practice, a certain variation in absorbed dose will exist throughout the sample. Absorbed-dose mapping is used to determine the magnitude, location, and reproducibility of the maximum (Dmax) and minimum absorbed dose (Dmin) for a given set of experimental parameters. Dosimeters used for dose mapping must be capable of operation over the expected range of doses and must have sufficient spatial resolution to determine likely dose gradients (see ISO/ASTM 52303).4.5 Computer simulations might provide useful information about absorbed-dose distribution in the irradiated sample, especially near material interfaces (see ASTM E2232), but are not a substitute for dosimetry.1.1 This document covers essential recommendations for dosimetry needed to conduct research on the effects of ionizing radiation on materials, products and biological samples. Such research includes establishment of the quantitative relationship between absorbed dose and the relevant effects. This document also describes the overall need for dosimetry in such research, and for reporting of the results. Dosimetry should be considered an integral part of the experiment, and the researcher is responsible for ensuring the accuracy and applicability of the dosimetry system used.NOTE 1: For research involving food products, note that the Codex Alimentarius Commission has developed an international General Standard and a Code of Practice that address the application of ionizing radiation to the treatment of foods and which strongly emphasizes the role of dosimetry for ensuring that irradiation will be properly performed (1).2NOTE 2: This document includes tutorial information in the form of Notes. Researchers should also refer to the references provided at the end of the standard, and other applicable scientific literature, to assist in the experimental methodology as applied to dosimetry (2-5).1.2 This document covers research conducted using the following types of ionizing radiation: gamma radiation (typically from Cobalt-60 or Cesium-137 sources), X-radiation (bremsstrahlung, typically with energies between 50 keV and 7.5 MeV), and electrons (typically with energies ranging from 80 keV to more than 10 MeV). See ISO/ASTM 51608, 51649, 51818 and 51702.1.3 This document describes dosimetry recommendations for establishing the experimental method. It does not include dosimetry recommendations for installation qualification or operational qualification of the irradiation facility. These subjects are treated in ISO/ASTM 51608, 51649, 51818 and 51702.1.4 This document is not intended to limit the flexibility of the researcher in the determination of the experimental methodology. The purpose of the document is to ensure that the radiation source and experimental methodology are chosen such that the results of the experiment will be useful and understandable to other scientists and regulatory agencies. The total uncertainty in the absorbed-dose measurement results and the absorbed-dose variation within the irradiated sample should be taken into account in the interpretation of the research results (see ISO/ASTM Guide 51707).1.5 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ISO/ASTM 52628. This document is thus intended to be read in conjunction with ISO/ASTM 52628.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 Integral Mode Dosimetry—As shown in 3.2, two different integral relationships can be established using proton-recoil emulsion data. These two integral reactions can be obtained with roughly an order of magnitude reduction in scanning effort. Consequently, this integral mode is an important complementary alternative to the customary differential mode of NRE spectrometry. The integral mode can be applied over extended spatial regions, for example, perhaps up to as many as ten in-situ locations can be covered for the same scanning effort that is expended for a single differential measurement. Hence the integral mode is especially advantageous for dosimetry applications which require extensive spatial mapping, such as exist in Light Water Reactor-Pressure Vessel (LWR-PV) benchmark fields (see Test Method E1005). In low power benchmark fields, NRE can be used as integral dosimeters in a manner similar to RM, solid state track recorders (SSTR) and helium accumulation monitors (HAFM) neutron dosimeters (see Test Methods E854 and E910). In addition to spatial mapping advantages of these other dosimetry methods, NRE offer fine spatial resolution and can therefore be used in-situ for fine structure measurements. In integral mode scanning, both absolute reaction rates, that is I(ET) and J(Emin), are determined simultaneously. Separate software codes need to be used to permit operation of a computer based interactive system in the integral mode (see Section 9). It should be noted that the integrals I(ET) and J(Emin) possess different units, namely proton-recoil tracks/MeV per hydrogen atom and proton-recoil tracks per hydrogen atom, respectively. 4.2 Applicability for Spectral Adjustment Codes—In the integral mode, NRE provide absolute integral reaction rates that can be used in neutron spectrum least squares adjustment codes (see Guide E944). In the past, such adjustment codes could not utilize NRE integral reaction rates because of the non-existence of NRE data. NRE integral reaction rates provide unique benchmark data for use in least squares spectral adjustment codes. The unique significance of NRE integral data arises from a number of attributes, which are described separately below. Thus, inclusion of NRE integral reaction rate data in the spectral adjustment calculations can result in a significant improvement in the determination of neutron spectra in low power benchmark fields. 4.3 The Neutron Scattering Cross Section of Hydrogen—Integral NRE reaction rates are based on the standard neutron scattering cross section of hydrogen. For fast neutron spectrometry and dosimetry applications, the accuracy of this (n,p) cross section over extended energy regions is essentially unmatched. A semi-empirical representation of the energy-dependence of the (n,p) cross section is given in Eq 13. where: E is in MeV and σnp(E) is in barns. This energy-dependent representation of the (n,p) cross section possesses an uncertainty of approximately 1 % at the (1σ) level (19). 4.4 Threshold Energy Definition—In contrast with all other fast neutron dosimetry cross sections, the threshold energy of the I and J integral reaction rates can be varied. NRE integral reaction threshold variability extends down to approximately 0.3 to 0.4 MeV, which is the lower limit of applicability of the NRE method. Threshold variation is readily accomplished by using different lower bounds of proton track length to analyze NRE proton-recoil track length distributions. Furthermore, these NRE thresholds are more accurately defined than the corresponding thresholds of all other fast neutron dosimetry cross sections. NRE therefore provide a response with an extremely sharp energy cutoff that is not only unmatched by other cross sections, but an energy threshold that is independent of the in-situ neutron spectrum. No other fast neutron dosimetry cross sections possess a threshold response with these significant attributes. The behavior of the I-integral and J-integral response for different threshold energies is shown in Figs. 2 and 3, respectively, in comparison to the threshold 237Np(n,f) reaction used in RM dosimetry. FIG. 2 Comparison of the I-Integral Response with the 237Np (n,f) Threshold Reaction FIG. 3 Comparison of the J-Integral Response for ET = 0.404, 0.484, 0.554 and 0.620 MeV with the 237Np (n,f) Threshold Reaction 4.5 Complimentary Energy Response—It is of interest to compare the differential energy responses available from these two integral relations. From Eq 4 and 11, one finds responses of the form σ(E)/ E and (1 –Emin/E)σ(E) for the I and J integral relations, respectively. These two responses are compared in Fig. 4 using a common cut-off of 0.5 MeV for both ET and Emin. Since these two responses are substantially different, simultaneous application of these two integral relations would be highly advantageous. As shown in Fig. 4, the energy response of the I and J integral reaction rates complement each other. The J-integral response increases with increasing neutron energy above the threshold value and therefore possesses an energy dependence qualitatively similar to most fast neutron dosimetry cross sections. However, significant quantitative differences exist. As discussed above, the J-integral response is more accurately defined in terms of both the energy-dependent cross section and threshold energy definition. The I-integral possesses a maximum value at the threshold energy and decreases rapidly from this maximum value as neutron energy increases above the threshold value. As can be seen in Fig. 4, the I-integral possesses a much more narrowly defined energy response than the J-integral. While the J-integral response is broadly distributed, most of the I-integral response is concentrated in the neutron energy just above threshold. As a consequence, the I-integral reaction rate data generally provides a more rigorous test of the ability of neutron transport calculations to describe the complex spatial and energy variations that exist in benchmark fields than does the J-integral data. This conclusion is supported by the calculation to experiment ratios (C/E) obtained from NRE experiments in the VENUS-1 LWR-PV benchmark field. For these VENUS-1 NRE experiments, the C/E values for the I integral possessed larger variation and deviated more widely from unity than the corresponding C/E values for the J-integral (20). FIG. 4 Energy Dependent Response for the Integral Reactions I(ET) and J(Emin) 1.1 Nuclear Research Emulsions (NRE) have a long and illustrious history of applications in the physical sciences, earth sciences and biological sciences (1, 2)2. In the physical sciences, NRE experiments have led to many fundamental discoveries in such diverse disciplines as nuclear physics, cosmic ray physics and high energy physics. In the applied physical sciences, NRE have been used in neutron physics experiments in both fission and fusion reactor environments (3-6). Numerous NRE neutron experiments can be found in other applied disciplines, such as nuclear engineering, environmental monitoring and health physics. Given the breadth of NRE applications, there exist many textbooks and handbooks that provide considerable detail on the techniques used in the NRE method (1-4, 6). As a consequence, this practice will be restricted to the application of the NRE method for neutron measurements in reactor physics and nuclear engineering with particular emphasis on neutron dosimetry in benchmark fields (see Matrix E706). 1.2 NRE are passive detectors and provide time integrated reaction rates. As a consequence, NRE provide fluence measurements without the need for time-dependent corrections, such as arise with radiometric (RM) dosimeters (see Test Method E1005). NRE provide permanent records, so that optical microscopy observations can be carried out any time after exposure. If necessary, NRE measurements can be repeated at any time to examine questionable data or to obtain refined results. 1.3 Since NRE measurements are conducted with optical microscopes, high spatial resolution is afforded for fine structure experiments. The attribute of high spatial resolution can also be used to determine information on the angular anisotropy of the in-situ neutron field (4, 5, 7). It is not possible for active detectors to provide such data because of in-situ perturbations and finite-size effects (see Section 11). 1.4 The existence of hydrogen as a major constituent of NRE affords neutron detection through neutron scattering on hydrogen, that is, the well known (n,p) reaction. NRE measurements in low power reactor environments have been predominantly based on this (n,p) reaction. NRE have also been used to measure the 6Li (n,t) 4He and the 10B (n,α) 7Li reactions by including 6Li and 10B in glass specks near the mid-plane of the NRE (8, 9). Use of these two reactions does not provide the general advantages of the (n,p) reaction for neutron dosimetry in low power reactor environments (see Section 4). As a consequence, this standard will be restricted to the use of the (n,p) reaction for neutron dosimetry in low power reactor environments. 1.5 Limitations—The NRE method possesses four major limitations for applicability in low power reactor environments. 1.5.1 Gamma-Ray Sensitivity—Gamma-rays create a significant limitation for NRE measurements. Above a gamma-ray exposure of approximately 0.025 Gy, NRE can become fogged by gamma-ray induced electron events. At this level of gamma-ray exposure, neutron induced proton-recoil tracks can no longer be accurately measured. As a consequence, NRE experiments are limited to low power environments such as found in critical assemblies and benchmark fields. Moreover, applications are only possible in environments where the buildup of radioactivity, for example, fission products, is limited. 1.5.2 Low Energy Limit—In the measurement of track length for proton recoil events, track length decreases as proton-recoil energy decreases. Proton-recoil track length below approximately 3μm in NRE cannot be adequately measured with optical microscopy techniques. As proton-recoil track length decreases below approximately 3 μm, it becomes very difficult to measure track length accurately. This 3-μm track length limit corresponds to a low energy limit of applicability in the range of approximately 0.3 to 0.4 MeV for neutron induced proton-recoil measurements in NRE. 1.5.3 High-Energy Limits—As a consequence of finite-size limitations, fast-neutron spectrometry measurements are limited to ≤15 MeV. The limit for in-situ spectrometry in reactor environments is ≤8MeV. 1.5.4 Track Density Limit—The ability to measure proton recoil track length with optical microscopy techniques depends on track density. Above a certain track density, a maze or labyrinth of overlapping tracks is created, which precludes the use of optical microscopy techniques. For manual scanning, this limitation arises above approximately 104 tracks/cm2, whereas interactive computer-based scanning systems can extend this limit up to approximately 105 tracks/cm2. These limits correspond to neutron fluences of 106 − 10 7 cm−2, respectively. 1.6 Neutron Spectrometry (Differential Measurements)—For differential neutron spectrometry measurements in low-power reactor environments, NRE experiments can be conducted in two different modes. In the more general mode, NRE are irradiated in-situ in the low power reactor environment. This mode of NRE experiments is called the 4π mode, since the in-situ irradiation creates tracks in all directions (see 3.1.1). In special circumstances, where the direction of the neutron flux is known, NRE are oriented parallel to the direction of the neutron flux. In this orientation, one edge of the NRE faces the incident neutron flux, so that this measurement mode is called the end-on mode. Scanning of proton-recoil tracks is different for these two different modes. Subsequent data analysis is also different for these two modes (see 3.1.1 and 3.1.2). 1.7 Neutron Dosimetry (Integral Measurements)—NRE also afford integral neutron dosimetry through use of the (n,p) reaction in low power reactor environments. Two different types of (n,p) integral mode dosimetry reactions are possible, namely the I-integral (see 3.2.1) and the J-integral (see 3.2.2) (10, 11). Proton-recoil track scanning for these integral reactions is conducted in a different mode than scanning for differential neutron spectrometry (see 3.2). Integral mode data analysis is also different than the analysis required for differential neutron spectrometry (see 3.2). This practice will emphasize NRE (n,p) integral neutron dosimetry, because of the utility and advantages of integral mode measurements in low power benchmark fields. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Research O.N. correlates with commercial automotive spark-ignition engine antiknock performance under mild conditions of operation.5.2 Research O.N. is used by engine manufacturers, petroleum refiners and marketers, and in commerce as a primary specification measurement related to the matching of fuels and engines.5.2.1 Empirical correlations that permit calculation of automotive antiknock performance are based on the general equation:Values of k1, k2, and k3 vary with vehicles and vehicle populations and are based on road-O.N. determinations.5.2.2 Research O.N., in conjunction with Motor O.N., defines the antiknock index of automotive spark-ignition engine fuels, in accordance with Specification D4814. The antiknock index of a fuel approximates the Road octane ratings for many vehicles, is posted on retail dispensing pumps in the U.S., and is referred to in vehicle manuals.This is more commonly presented as:5.2.3 Research O.N. is also used either alone or in conjunction with other factors to define the Road O.N. capabilities of spark-ignition engine fuels for vehicles operating in areas of the world other than the United States.5.3 Research O.N. is used for measuring the antiknock performance of spark-ignition engine fuels that contain oxygenates.5.4 Research O.N. is important in relation to the specifications for spark-ignition engine fuels used in stationary and other nonautomotive engine applications.1.1 This laboratory test method covers the quantitative determination of the knock rating of liquid spark-ignition engine fuel in terms of Research O.N., including fuels that contain up to 25 % v/v of ethanol. However, this test method may not be applicable to fuel and fuel components that are primarily oxygenates.2 The sample fuel is tested using a standardized single cylinder, four-stroke cycle, variable compression ratio, carbureted, CFR engine run in accordance with a defined set of operating conditions. The O.N. scale is defined by the volumetric composition of PRF blends. The sample fuel knock intensity is compared to that of one or more PRF blends. The O.N. of the PRF blend that matches the K.I. of the sample fuel establishes the Research O.N.1.2 The O.N. scale covers the range from 0 to 120 octane number but this test method has a working range from 40 to 120 Research O.N. Typical commercial fuels produced for spark-ignition engines rate in the 88 to 101 Research O.N. range. Testing of gasoline blend stocks or other process stream materials can produce ratings at various levels throughout the Research O.N. range.1.3 The values of operating conditions are stated in SI units and are considered standard. The values in parentheses are the historical inch-pound units. The standardized CFR engine measurements continue to be in inch-pound units only because of the extensive and expensive tooling that has been created for this equipment.1.4 For purposes of determining conformance with all specified limits in this standard, an observed value or a calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in expressing the specified limit, in accordance with the rounding method of Practice E29.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see Section 8, 14.4.1, 15.5.1, 16.6.1, Annex A1, A2.2.3.1, A2.2.3.3 (6) and (9), A2.3.5, X3.3.7, X4.2.3.1, X4.3.4.1, X4.3.9.3, X4.3.11.4, and X4.5.1.8.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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This specification covers the performance requirements for a high octane number test fuel suitable for spark-ignition engines to be used in ground vehicles that will require 100 research octane number (RON) minimum rated fuel. The fuels described by this specification are intended for developing technologies that lead to reduced vehicle energy consumption, such as higher compression ratio, higher power density, increased turbocharger boost pressure, smaller swept displacement volume, and operation at lower engine speeds. These fuels may contain oxygenates, such as alcohols and ethers, up to 50% by volume, and both fossil and bio-derived components.This specification prescribes the vapor pressure and distillation requirements as well as the oxygenate blendstock requirements for a high octane number test fuel. It also covers the ordering information, test methods, workmanship, sampling, containers, and sample handling.1.1 This specification covers the requirements of a high octane number test fuel suitable for spark-ignition engines to be utilized in ground vehicles that will require 100 research octane number (RON) minimum rated fuel.1.1.1 The fuels described by this specification are intended for developing technologies that lead to reduced vehicle energy consumption, such as higher compression ratio, higher power density, increased turbocharger boost pressure, smaller swept displacement volume, and operation at lower engine speeds.1.1.2 The fuels described in this test fuel specification may not meet all of the performance or regulatory requirements for use in vehicles using commercial gasoline.1.2 The fuels covered in this specification may contain oxygenates, such as alcohols and ethers, up to 50 % by volume. This specification covers fuels that may contain both fossil and bio-derived components.1.3 This specification provides a description of high RON test fuel for automotive spark-ignition engines that are not currently in the marketplace but are being developed and require a defined standard test fuel. The high RON fuel could become available in the marketplace if/when such engines are introduced in commerce. The specification is under continuous review, which can result in revisions based on changes in fuel, automotive requirements, or test methods, or a combination thereof. All users of this specification, therefore, should refer to the latest edition.NOTE 1: If there is any doubt as to the latest edition of Specification D8076, contact ASTM International Headquarters.1.4 The values stated in SI units are the standard.1.4.1 Exception—Non-SI values are provided for information only. U.S. federal regulations frequently specify non-SI units.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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This practice establishes essential and renumbered elements in the design, conduct, and reporting of research (both laboratory and field) on the psychophysiological detection of deception (polygraph). In laboratory research, all procedures shall be documented in sufficient detail such that others can replicate them. Subject manipulation shall require minimal human interaction; however, when human interaction is deemed necessary, such procedure shall be standardized to the extent possible. Also, when studies of exploratory nature are conducted, they shall be clearly identified as exploratory studies. In field research, on the other hand, the procedure for case selection shall be reported in sufficient detail, including the qualifications of the polygraph testing and chart evaluating participants. In cases where departures from conventional field practice are encountered, these shall be documented in sufficient detail including an explanation for the nonstandard procedures. For both laboratory and field research, statements of generalization shall be limited to those which can be supported by data, procedures, and statistical methodology. Polygraph testing shall be carried out in terms of evidentiary psychophysiological detection of deception (PDD) examinations and investigative PDD examinations, the validity and utility of which shall conform to the requirements specified. Investigative PDD examinations may resort to a "successive hurdles" approach to satisfy the minimum validity requirements.1.1 This practice establishes essential and recommended elements in the design, conduct, and reporting of research on psychophysiological detection of deception (polygraph) (PDD). Analog and field research are addressed separately.1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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