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Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Nickel
ASTM E264-25
Organization:
ASTM - ASTM International
Year: 2025
Abstract: 5.1 Refer to Guide E844 for the selection, irradiation, and quality control of neutron dosimeters. 5.2 Refer to Practice E261 for a general discussion of the determination of fast-neutron fluence rate with threshold detectors. 5.3 Pure nickel in the form of foil or wire is readily available and easily handled. 5.4 58Co has a half-life of 70.85 (3) days (1, 2)3 and emits a gamma ray with an energy of 810.7602 (20) keV (2, 3). 5.5 Competing activities 65Ni(2.5172 h) and 57Ni(35.9 (3) h (2) are formed by the reactions 64Ni(n,γ) 65Ni and 58Ni(n,2n)57Ni, respectively. 5.6 A second 9.04 h isomer, 58mCo, is formed that decays to 70.85 day 58Co. Loss of 58Co and 58mCo by thermal-neutron burnout will occur in environments (4, 5) having thermal fluence rates of 3 × 1012 cm−2·s −1 and above. Burnout correction factors, R, are plotted as a function of time for several thermal fluxes in Fig. 1. Tabulated values for a continuous irradiation time are provided in Hogg et al. (5). Note 1: The data is taken from the International Reactor Dosimetry and Fusion File (IRDFF-II, the legend of the above plot to be updated). For more details, see Ref (7).
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Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Nickel
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| contributor author | ASTM - ASTM International | |
| date accessioned | 2025-09-30T19:29:01Z | |
| date available | 2025-09-30T19:29:01Z | |
| date copyright | 2025 | |
| date issued | 2025 | |
| identifier other | e0264-25.pdf | |
| identifier uri | http://yse.yabesh.ir/std;query=autho170393FD081DAC4/handle/yse/343815 | |
| description abstract | 5.1 Refer to Guide E844 for the selection, irradiation, and quality control of neutron dosimeters. 5.2 Refer to Practice E261 for a general discussion of the determination of fast-neutron fluence rate with threshold detectors. 5.3 Pure nickel in the form of foil or wire is readily available and easily handled. 5.4 58Co has a half-life of 70.85 (3) days (1, 2)3 and emits a gamma ray with an energy of 810.7602 (20) keV (2, 3). 5.5 Competing activities 65Ni(2.5172 h) and 57Ni(35.9 (3) h (2) are formed by the reactions 64Ni(n,γ) 65Ni and 58Ni(n,2n)57Ni, respectively. 5.6 A second 9.04 h isomer, 58mCo, is formed that decays to 70.85 day 58Co. Loss of 58Co and 58mCo by thermal-neutron burnout will occur in environments (4, 5) having thermal fluence rates of 3 × 1012 cm−2·s −1 and above. Burnout correction factors, R, are plotted as a function of time for several thermal fluxes in Fig. 1. Tabulated values for a continuous irradiation time are provided in Hogg et al. (5). Note 1: The data is taken from the International Reactor Dosimetry and Fusion File (IRDFF-II, the legend of the above plot to be updated). For more details, see Ref (7). | |
| language | English | |
| title | Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Nickel | en |
| title | ASTM E264-25 | num |
| type | standard | |
| status | Active | |
| tree | ASTM - ASTM International:;2025 | |
| contenttype | fulltext | |
| scope | 1.1 This test method covers procedures for measuring reaction rates by the activation reaction 58Ni(n,p)58Co. 1.2 This activation reaction is useful for measuring neutrons with energies above approximately 2.1 MeV and for irradiation times up to about 200 days in the absence of high thermal neutron fluence rates, provided that the analysis methods described in Practice E261 are followed. If dosimeters are analyzed after irradiation periods longer than 200 days, the information inferred about the fluence during irradiation periods more than 200 days before the end of the irradiation should not be relied upon without supporting data from dosimeters withdrawn earlier. 1.3 With suitable techniques, fission-neutron fluence rates densities above 107 cm−2·s−1 can be determined. 1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E261. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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. | |
| identifier DOI | 10.1520/E0264-25 |