{"title":"22Na 半衰期的测量和支持指数衰减规律的证据","authors":"S. Pommé , H. Stroh , J. Paepen","doi":"10.1016/j.nds.2024.01.002","DOIUrl":null,"url":null,"abstract":"<div><p>The half-life of <sup>22</sup>Na has been determined through 523 activity measurements over 14.5 years with a re-entrant ionisation chamber in a temperature-stabilised room. The data were selected and aggregated from in total 127 830 ionisation current measurements with a reproducibility of the order of 0.065<!--> <!-->% standard deviation. The ionisation current was collected over an air capacitor and measured as a change of voltage over time, which warrants excellent linearity with activity throughout the experiment. The residuals to an exponential decay curve show a distinct annual cycle of 0.0055 (5)<!--> <!-->% amplitude, which reduces to 0.0012 (5)<!--> <!-->% after compensation for a correlation with ambient humidity. The data confirm the validity of the exponential-decay law, in absence of cyclic perturbations at daily, monthly, and multi-annual scale at the level of 0.0005<!--> <!-->% standard deviation. The <sup>22</sup>Na half-life value obtained in this study is 950.68 (12) d or 2.60290 (34) a, with a relative standard uncertainty of 0.013<!--> <!-->%. This value is consistent with the mean value of other measurement results in the literature, although the latter have an issue with incomplete uncertainty budgets. Owing to the high statistical accuracy and conservative uncertainty estimate of systematic errors, the result obtained in this work can be recommended as a reliable reference value.</p></div>","PeriodicalId":49735,"journal":{"name":"Nuclear Data Sheets","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0090375224000024/pdf?md5=7dc354d98673d4d756cda9b73dfc3296&pid=1-s2.0-S0090375224000024-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Measurement of the 22Na half-life and evidence supporting the exponential-decay law\",\"authors\":\"S. Pommé , H. Stroh , J. Paepen\",\"doi\":\"10.1016/j.nds.2024.01.002\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The half-life of <sup>22</sup>Na has been determined through 523 activity measurements over 14.5 years with a re-entrant ionisation chamber in a temperature-stabilised room. The data were selected and aggregated from in total 127 830 ionisation current measurements with a reproducibility of the order of 0.065<!--> <!-->% standard deviation. The ionisation current was collected over an air capacitor and measured as a change of voltage over time, which warrants excellent linearity with activity throughout the experiment. The residuals to an exponential decay curve show a distinct annual cycle of 0.0055 (5)<!--> <!-->% amplitude, which reduces to 0.0012 (5)<!--> <!-->% after compensation for a correlation with ambient humidity. The data confirm the validity of the exponential-decay law, in absence of cyclic perturbations at daily, monthly, and multi-annual scale at the level of 0.0005<!--> <!-->% standard deviation. The <sup>22</sup>Na half-life value obtained in this study is 950.68 (12) d or 2.60290 (34) a, with a relative standard uncertainty of 0.013<!--> <!-->%. This value is consistent with the mean value of other measurement results in the literature, although the latter have an issue with incomplete uncertainty budgets. Owing to the high statistical accuracy and conservative uncertainty estimate of systematic errors, the result obtained in this work can be recommended as a reliable reference value.</p></div>\",\"PeriodicalId\":49735,\"journal\":{\"name\":\"Nuclear Data Sheets\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-02-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0090375224000024/pdf?md5=7dc354d98673d4d756cda9b73dfc3296&pid=1-s2.0-S0090375224000024-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nuclear Data Sheets\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0090375224000024\",\"RegionNum\":1,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Data Sheets","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0090375224000024","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, NUCLEAR","Score":null,"Total":0}
Measurement of the 22Na half-life and evidence supporting the exponential-decay law
The half-life of 22Na has been determined through 523 activity measurements over 14.5 years with a re-entrant ionisation chamber in a temperature-stabilised room. The data were selected and aggregated from in total 127 830 ionisation current measurements with a reproducibility of the order of 0.065 % standard deviation. The ionisation current was collected over an air capacitor and measured as a change of voltage over time, which warrants excellent linearity with activity throughout the experiment. The residuals to an exponential decay curve show a distinct annual cycle of 0.0055 (5) % amplitude, which reduces to 0.0012 (5) % after compensation for a correlation with ambient humidity. The data confirm the validity of the exponential-decay law, in absence of cyclic perturbations at daily, monthly, and multi-annual scale at the level of 0.0005 % standard deviation. The 22Na half-life value obtained in this study is 950.68 (12) d or 2.60290 (34) a, with a relative standard uncertainty of 0.013 %. This value is consistent with the mean value of other measurement results in the literature, although the latter have an issue with incomplete uncertainty budgets. Owing to the high statistical accuracy and conservative uncertainty estimate of systematic errors, the result obtained in this work can be recommended as a reliable reference value.
期刊介绍:
The Nuclear Data Sheets are current and are published monthly. They are devoted to compilation and evaluations of experimental and theoretical results in Nuclear Physics. The journal is mostly produced from Evaluated Nuclear Structure Data File (ENSDF), a computer file maintained by the US National Nuclear Data Center