Metrologia最新文献

{"title":"Development and implementation of an automated four-terminal-pair Josephson impedance bridge","authors":"Yoawaret Pimsut, S. Bauer, M. Kraus, Ralf Behr, M. Kruskopf, O.F. Kieler, L. Palafox","doi":"10.1088/1681-7575/ad2539","DOIUrl":"https://doi.org/10.1088/1681-7575/ad2539","url":null,"abstract":"\u0000 The four-terminal-pair impedance bridge using pulse-driven Josephson voltage standards at PTB has been fully automated. The same bridge configuration was employed to determine R:R and C:C ratios over the frequency range between 53 Hz to 50 kHz. Only minor changes are needed to cover this large frequency range: amplifiers to increase the sensitivities of the current detections for low frequencies and signal generators with higher resolutions at high frequencies to reach 50 kHz. Furthermore, the bridge can be operated for quadrature R:(1/ωC) measurements. The combined standard uncertainties (k = 1) for the new bridge were evaluated for all operating frequencies. They reach 2 nF/F and 4 nΩ/Ω at 1233.15 Hz. At this frequency, the 10 nF:10 nF ratio matched the ratio of PTB's bridge employing inductive voltage dividers within 1 nF/F ± 3 nF/F (k = 1). Over 45 days, the 10 nF:10 nF ratio deviated less than -2 nF/F ± 3 nF/F (k = 1). The 12.9 kΩ:10 kΩ ratio at 53 Hz differed -2 nΩ/Ω ± 5 nΩ/Ω (k = 1) from the DC ratio measured by the PTB's cryogenic current comparator bridge. Using a 12.9 kΩ resistance standard and a graphene AC quantum Hall resistance, the 10 nF:10 nF ratios derived from quadrature measurements agreed with the PTB's inductive voltage divider bridge better than 9 nF/F ± 13 nF/F (k = 1).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139869889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and implementation of an automated four-terminal-pair Josephson impedance bridge","authors":"Yoawaret Pimsut, S. Bauer, M. Kraus, Ralf Behr, M. Kruskopf, O.F. Kieler, L. Palafox","doi":"10.1088/1681-7575/ad2539","DOIUrl":"https://doi.org/10.1088/1681-7575/ad2539","url":null,"abstract":"\u0000 The four-terminal-pair impedance bridge using pulse-driven Josephson voltage standards at PTB has been fully automated. The same bridge configuration was employed to determine R:R and C:C ratios over the frequency range between 53 Hz to 50 kHz. Only minor changes are needed to cover this large frequency range: amplifiers to increase the sensitivities of the current detections for low frequencies and signal generators with higher resolutions at high frequencies to reach 50 kHz. Furthermore, the bridge can be operated for quadrature R:(1/ωC) measurements. The combined standard uncertainties (k = 1) for the new bridge were evaluated for all operating frequencies. They reach 2 nF/F and 4 nΩ/Ω at 1233.15 Hz. At this frequency, the 10 nF:10 nF ratio matched the ratio of PTB's bridge employing inductive voltage dividers within 1 nF/F ± 3 nF/F (k = 1). Over 45 days, the 10 nF:10 nF ratio deviated less than -2 nF/F ± 3 nF/F (k = 1). The 12.9 kΩ:10 kΩ ratio at 53 Hz differed -2 nΩ/Ω ± 5 nΩ/Ω (k = 1) from the DC ratio measured by the PTB's cryogenic current comparator bridge. Using a 12.9 kΩ resistance standard and a graphene AC quantum Hall resistance, the 10 nF:10 nF ratios derived from quadrature measurements agreed with the PTB's inductive voltage divider bridge better than 9 nF/F ± 13 nF/F (k = 1).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-kilowatt cw laser power measurement comparison between national standards","authors":"Kyle A. Rogers, Paul Williams, M. Pastuschek, H. Lecher, Stefan Kueck, Marco A Lopez, John Lehman","doi":"10.1088/1681-7575/ad2538","DOIUrl":"https://doi.org/10.1088/1681-7575/ad2538","url":null,"abstract":"\u0000 We present here the first comparison between National Metrology Institutes (NMIs) of high accuracy continuous wave (cw) optical power measurements in the kilowatt regime. The National Institute of Standards and Technology (NIST) performed measurements with a power meter relying on photon momentum. The Physikalisch-Technische Bundesanstalt (PTB) performed measurements with a modified off-the-shelf thermal power meter. The non-absorbing photon momentum measurement approach permits the two power meters to measure the same laser beam optical path simultaneously, resulting in a direct comparison of the meters supported by an optical system to accommodate differences in instrument settling times. The results show agreement within the expanded uncertainties for each instrument. NIST and PTB illustrate a degree of equivalence of 0.49% with an expanded uncertainty of 1.37% (k=2) for an average result across all power levels.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139809594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trap induced broadening in a potential hydrogen lattice clock","authors":"J P Scott, R M Potvliege, D Carty, M P A Jones","doi":"10.1088/1681-7575/ad1e37","DOIUrl":"https://doi.org/10.1088/1681-7575/ad1e37","url":null,"abstract":"We consider the potential use of optical traps for precision measurements in atomic hydrogen (H). Using an implicit summation method, we calculate the atomic polarisability, the rates of elastic/inelastic scattering and the ionisation rate in the wavelength range (395–1000) nm. We extend previous work to predict three new magic wavelengths for the 1S–2S transition. At the magic wavelengths, the 1S–2S transition is unavoidably and significantly broadened due to trap-induced ionisation associated with the high intensity required to trap the 1S state. However, we also find that this effect is partially mitigated by the low mass of H, which increases the trap frequency, enabling Lamb–Dicke confinement in shallow lattices. We find that a H optical lattice clock, free from the motional systematics which dominate in beam experiments, could operate with an intrinsic linewidth of the order of 1 kHz. Trap-induced losses are shown not to limit measurements of other transitions.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139755167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practical realisation of the kelvin by Johnson noise thermometry","authors":"S P Benz, Kevin J Coakley, N. Flowers-Jacobs, Horst Rogalla, W. Tew, J F Qu, D. R. White, C. Gaiser, Alessio Pollarollo, Chiharu Urano","doi":"10.1088/1681-7575/ad2273","DOIUrl":"https://doi.org/10.1088/1681-7575/ad2273","url":null,"abstract":"\u0000 Johnson noise thermometry (JNT) is a purely electronic method of thermodynamic thermometry. In primary JNT, the temperature is inferred from a comparison of the Johnson noise voltage of a resistor at the unknown temperature with a pseudo-random noise synthesized by a quantum-based voltage-noise source (QVNS). The advantages of the method are that it relies entirely on electronic measurements, and it can be used over a wide range of temperatures due to the ability of the QVNS to generate programmable, scalable, and accurate reference signals. The disadvantages are the requirement of cryogenic operation of the QVNS, the need to match the frequency responses of the leads of the sense resistor and the QVNS, and long measurement times. This review collates advice on current best practice for a primary Johnson noise thermometer based on the switched correlator and QVNS. The method achieves an uncertainty of about 1 mK near 300 K and is suited to operation between 4 K and 1000 K.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139598160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The isotopic composition of the new enriched silicon crystal Si28-31Pr11: Maintaining the realization and dissemination of the mole and the kilogram via the XRCD method","authors":"A. Pramann, O. Rienitz","doi":"10.1088/1681-7575/ad2272","DOIUrl":"https://doi.org/10.1088/1681-7575/ad2272","url":null,"abstract":"\u0000 The molar mass and isotopic composition of a new silicon single crystal material (Si28-31Pr11) highly enriched in 28Si has been determined in the context of the X-ray crystal density (XRCD) method used for the realization and dissemination of the SI base units ‒ the mole and the kilogram. Isotope ratio measurements have been performed using a high-resolution multicollector-inductively coupled plasma mass spectrometer (MC-ICP-MS) with improved technical performance. By applying the Virtual-Element Isotope Dilution Mass Spectrometry (VE-IDMS) method, different crystal areas enclosing the locations of two silicon spheres have been investigated with respect to the magnitude of tentative variations in the molar mass and isotopic composition of the respective samples as a function of their original location in the crystal ingot. In total, 18 subsamples from four different axial and several related radial posi-tions have been characterized. An average molar mass M(Si28-31Pr11) = 27.976 941 464(41) g mol-1 corresponding to a relative combined uncertainty u\u0000 c,rel(M(Si28-31Pr11)) = 1.4 × 10-9 was yielded. The average enrichment in 28Si of the crystal is expressed by the mean amount-of-substance fraction x(28Si) = 0.999 985 350(37) mol/mol. Two spheres were cut from the crystal ingot. The average molar masses of the spheres Si28kg_03_a and Si28kg_03_b are: M(Si28kg_03_a) = 27.976 941 467(43) g mol-1 and M(Si28kg_03_b) = 27.976 941 461(44) g mol-1, respectively. The results are discussed using uncertainty budgets according to the Guide to the expression of uncertainty in measurement (GUM). A homogeneous distribution of the molar mass throughout the crystal is suggested, qualifying it as a material for a primary stand-ard – a silicon sphere – for the realization and dissemination of the mole and the kilogram. A comparison with enriched silicon crystals that are already available is given.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139597859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supplementary comparison SIM.M.FF-S9.2016 for water flow measurement","authors":"E Frahm, R Arias, M Maldonado, J Vargas, J J Mendoza, A Arredondo, M A Silvosa","doi":"10.1088/0026-1394/61/1a/07001","DOIUrl":"https://doi.org/10.1088/0026-1394/61/1a/07001","url":null,"abstract":"<title>Main text</title>The objective of the Supplementary Comparison (SC) SIM.M.FF-S9 for water flow measurement was to support and prove the Calibration and Measurement Capabilities (CMC) of the participating NMIs of Chile (CISA), Peru (INACAL), Bolivia (IBMETRO) and Argentina (INTI). As pilot laboratories, the national metrology institutes of Germany (PTB) and CENAM (Mexico) supported the comparison with reference values. The comparison was organized as a single round robin, started in January 2016 at PTB and finished in August 2019, also at PTB. A combined setup of a turbine meter and Coriolis meter was used as a transfer standard. The nominal calibration conditions of the SC were defined in the flow range between 10 m³/h and 130 m³/h, 20 °C fluid temperature and 0.3 MPa line pressure. In order to estimate the uncertainties <italic toggle=\"yes\">u</italic>\u0000_TS, both transfer meters were subjected to extensive characterization measurements at pilot laboratory PTB. The following parameters were researched in detail: fluid temperature, line pressure, reproducibility, flow stability and meter sensitivity to different inflow conditions. The <italic toggle=\"yes\">E</italic>\u0000_N values for the turbine meter were calculated based on PTB data, only. The <italic toggle=\"yes\">E</italic>\u0000_N values for the Coriolis meter are partly linked to Key Comparison CCM.FF-K1.2015 and were calculated using a common reference value of PTB and CENAM data. The uncertainty of turbine meter <italic toggle=\"yes\">u</italic>\u0000_TS was clearly dominated by the sensitivity to disturbed inflow conditions which leads to large values of <italic toggle=\"yes\">u</italic>\u0000_TS with &gt; 0.20 %. Beside one calibration, all labs passed the <italic toggle=\"yes\">E</italic>\u0000_N criteria of ≤ 1.20. But, due to large values of <italic toggle=\"yes\">u</italic>\u0000_TS, the calibrations for all labs were evaluated as inconclusive. The evaluation criteria <italic toggle=\"yes\">u</italic>\u0000_comp/<italic toggle=\"yes\">u</italic>\u0000_base exceeded the critical value of 2.00 for all calibrations. Finally, the turbine meter was not suitable for a confirmation of the submitted CMC values. The calibration results of the Coriolis meter were characterized by a strong dependency on zero setting. The observed effect was adjusted for the data of both reference laboratories by introducing a new method for autozero correction. Maximum uncertainty values for Coriolis <italic toggle=\"yes\">u</italic>\u0000_TS were estimated with 0.069 % at low flowrates and 0.033 % at high flowrates. Besides two calibrations, all laboratories complied with the <italic toggle=\"yes\">E</italic>\u0000_N criteria of ≤ 1.20. In contrast to turbine meter, the evaluation criteria <italic toggle=\"yes\">u</italic>\u0000_comp/<italic toggle=\"yes\">u</italic>\u0000_base exceeded the critical value of 2.00 at one calibration, o","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139509517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"APMP.QM-S19: Toxic elements in seafood","authors":"Kelvin Chun-wai Tse, Wai-hong Fung, Mala Khan, Soraya Sandoval Riquelme, Javier Vera, Li Xiao, Lu Hai, Ronald Cristancho, Adriana Rodriguez, Diego A Garzon Z , Carlos Andres España, Elias Kakoulides, G Karanikolopoulos, E Stathoudaki, V Schoina, Christine Elishian, Isna Komalasari, Luigi Bergamaschi, Giancarlo D'Agostino, Marco di Luzio, Shin-ichi Miyashita, Maria-del-Rocio Arvizu-Torres, Emilia Vasileva-Veleva, Elmer Carrasco, Alleni T Junsay, Michał Strzelec, Richard Shin, Radojko Jaćimović, Milena Horvat, Darja Mazej, Adna Alilović, Tea Zuliani, Angelique Botha, Maré Linsky, Nunnapus Laitip, Ramiro Pérez Zambra, Romina Napoli","doi":"10.1088/0026-1394/61/1a/08001","DOIUrl":"https://doi.org/10.1088/0026-1394/61/1a/08001","url":null,"abstract":"<title>Main text</title>Seafood is one of the major food resources for human consumption in the world. The CODEX Alimentarius Commission and many jurisdictions have set maximum levels of metallic contaminants in seafood. The use of reliable methods for measurement of metallic contaminants is important in safeguarding the quality of these products and public health.The Supplementary Comparison APMP.QM-S19: Toxic Elements in Seafood was coordinated by the Government Laboratory, Hong Kong, China (GLHK). Four measurands (arsenic, cadmium, mercury and lead) in seafood were chosen. The last CCQM or RMO key comparison / supplementary comparison in the area of metallic contaminants in seafood was organized by GLHK in 2011 (APMP.QM-S5). Hence, it was timely to organize another comparison that covers different measurands. This Supplementary Comparison (APMP.QM-S19) offers different analytical challenges (e.g. in analysis of mercury and a different range of measurands) as compared to the previous comparison. Moreover, it enabled National Metrology Institutes / Designated Institutes (NMIs/DIs) that did not participate in the previous comparisons to demonstrate their measurement competencies.Nineteen institutes participated in APMP.QM-S19. Most participating NMIs/DIs employed microwave-assisted acid digestion for sample dissolution. Inductively coupled plasma mass spectrometry (ICP-MS), including triple quadrupole and sector field, were the most commonly used instrumental techniques. Results of all participating NMIs/DIs were evaluated against the supplementary comparison reference value (SCRV). The SCRV and associated uncertainty were determined from results of NMIs/DIs that participated in the supplementary comparison using methods with demonstrated metrological traceability. Median was used as estimator of the SCRVs. For arsenic, the SCRV was 1.342 mg/kg calculated from 15 participating NMIs/DIs. For arsenic, cadmium, mercury and lead, the SCRVs were 1.342 mg/kg, 0.3630 mg/kg, 0.1230 mg/kg and 0.4101 mg/kg, respectively, calculated from 15, 14, 13 and 11 participating NMIs/DIs.Participating NMIs/DIs that have successfully participated in APMP.QM-S19 have demonstrated measurement capabilities in determining inorganic elements, in a mass fraction range from 0.02 mg/kg to 50 mg/kg in high organic content matrix, including seafood of animal origin and high protein food.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/apmp-qm-s19\" xlink:type=\"simple\">Final Report</ext-link>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <ext-link xlink:href=\"https://www.bipm.org/kcdb/\" xlink:type=\"simple\">https://www.bipm.org/kcdb/</ext-link>.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139509074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CCEM key comparison CCEM.RF-K26. Attenuation at 18 GHz, 26.5 GHz and 40 GHz using a step attenuator. Final report of the pilot laboratory","authors":"A Widarta","doi":"10.1088/0026-1394/61/1a/01001","DOIUrl":"https://doi.org/10.1088/0026-1394/61/1a/01001","url":null,"abstract":"<title>Main text</title>This report summarizes the results of the Key Comparison CCEM.RF-K26 Attenuation at 18 GHz, 26.5 GHz and 40 GHz using a step attenuator which has been performed from January 2015 to February 2018. Fourteen National Metrology Institutes (NMIs) participated in this key comparison, including the National Metrology Institute of Japan (NMIJ/AIST, Japan) which served as pilot laboratory, the National Institute of Metrology (NIM, China), the Physikalisch-Technische Bundesanstal (PTB, Germany), the Laboratoire national de métrologie et d'essais (LNE, France), the Swiss Federal Office for Metrology and Accreditation (METAS, Switzerland), the National Physical Laboratory of India (NPLI, India), the All-Russian Scientific Research Institute of Physico-Technical Measurements (VNIIFTRI, Russia), the Korea Research Institute of Standard and Science (KRISS, South Korea), the National Physical Laboratory (NPL, United Kingdom), the National Metrology Institute of South Africa (NMISA, South Africa), the Tubitak Ulusal Metrologi Enstitűsű (TUBITAK-UME, Turkey), the National Metrology Centre (NMC-A*STAR, Singapore), the Czech Metrology Institute (CMI, Czech Republic) and the Instituto Nacional de Tecnica Aeroespacial (INTA, Spain). The Key Comparison Reference Values (KCRVs) were determined from the measurement results of five to ten participating NMIs, depending on the attenuation and frequency.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/ccem-rf-k26\" xlink:type=\"simple\">Final Report</ext-link>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <ext-link xlink:href=\"https://www.bipm.org/kcdb/\" xlink:type=\"simple\">https://www.bipm.org/kcdb/</ext-link>.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139509198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"International comparison of measurements of neutron source emission rate (2016-2021) - CCRI(III)-K9.Cf.2016","authors":"N J Roberts, N A Horwood, Z Vykydal, H Park, J Kim, W W Pereira, E S da Fonseca, C Thiam, Zhang Hui, M S Dewey, H P Mumm, H Harano, T Matsumoto, A Masuda, S Manabe, J P Archambault, N N Moiseev, A V Didyk","doi":"10.1088/0026-1394/61/1a/06001","DOIUrl":"https://doi.org/10.1088/0026-1394/61/1a/06001","url":null,"abstract":"<title>Main text</title>Section III (neutron measurements) of the Comité Consultatif des Rayonnements Ionisants, CCRI, conducted a comparison of primary measurements of the neutron emission rate of a ²⁵²Cf radionuclide source. A single ²⁵²Cf source was circulated to all participants between 2016 and 2020. Ten laboratories participated -CMI (Czech Republic), KRISS (Republic of Korea), IRD/LNMRI (Brazil), LNE-LNHB (France), NIM (China), NIST (USA), NMIJ (Japan), NPL (UK), NRC (Canada) and VNIIM (Russia) - with NPL making their measurements at the start and repeating them at the end of the exercise to verify the ²⁵⁰Cf content of the source. Each laboratory reported the emission rate into 4π sr together with a detailed uncertainty budget. All participants used the manganese bath technique except NMIJ who used a relative method based on measurements with a ³He detector in a graphite pile. VNIIM also made measurements using an associated particle technique. CMI, KRISS, LNE-LNHB, NIM, NPL and VNIIM also measured the anisotropy of the source although this did not formally form part of the comparison.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/ccri-iii-k9-cf-252-2016\" xlink:type=\"simple\">Final Report</ext-link>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <ext-link xlink:href=\"https://www.bipm.org/kcdb/\" xlink:type=\"simple\">https://www.bipm.org/kcdb/</ext-link>.The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139509348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}