A comparison of future realizations of the kilogram

Stöck, M; Barat, Pauline; Pinot, P.; Beaudoux, Florian; Espel, Patrick; Piquemal, F.; Thomas, Matthieu; Ziane, Djamel; Abbott, Patrick J.; Haddad, D.; Kubarych, Zeina J.; Pratt, Jon R.; Schlamminger, Stephan; Fujii, K.; Fujita, Kazuhiro; Kuramoto, Naoki; Mizushima, Shigeki; Zhang, L; Green, R G; Liard, J.; Sánchez, C.; Wood, B.M.; Bettin, H.; Borys, Michael; Busch, I.; Hämpke, M; Krumrey, Michael; Nicolaus, Arnold

doi:10.1088/1681-7575/aa9a7e

Cited by 26 publications

(15 citation statements)

References 11 publications

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“…In 2017, NMIJ used the AVO28-S5c sphere to remeasure N A , after the development of new apparatuses-a spectroscopic ellipsometer (operated both in vacuum and in air) [7], and an x-ray photoelectron spectroscopy system capable of accommodating 1 kg Si spheres [8]-to investigate the surfaces of the sphere independently from PTB. The measurement result, N A (NMIJ-17) = 6.022 140 84(15) × 10 23 mol −1 , (5) given in [9,10], was reported to the CCM pilot study on the comparison of future realizations of the kilogram [10,11] and takes the results of the extraordinary calibration [2,3] of the NMIJ mass standard into account. The molar mass and lattice parameter values published in 2015 [4] were used to obtain N A (NMIJ-17).…”

Section: Short Communicationmentioning

confidence: 99%

Avogadro constant measurements using enriched²⁸Si monocrystals

et al. 2017

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Section: Short Communicationmentioning

confidence: 99%

Avogadro constant measurements using enriched²⁸Si monocrystals

et al. 2017

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“…As an example, the uncertainty budget of the determination of m sphere using AVO28-S5c in 2017 is shown in Table 2 [4]. This determination was performed for a pilot study to compare the realizations of the kilogram by several national metrology institutes on the basis of the Planck constant in CODATA 2014 [24]. The values of a and A r (Si) of AVO28-S5c were measured with relative uncertainties of 1.8 9 10 -9 and 5.4 9 10 -9 , respectively, by the IAC project [9,11].…”

Section: Mass Of Si Spherementioning

confidence: 99%

Realization of the New Kilogram Using 28Si-Enriched Spheres and Dissemination of Mass Standards at NMIJ

Kuramoto

Mizushima

Zhang

et al. 2020

MAPAN

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The new definition of the kilogram was implemented on May 20, 2019. The kilogram is presently defined by a fixed value of the Planck constant. On the basis of the new definition, the kilogram will be realized at the National Metrology Institute of Japan by the X-ray crystal density method using 28Si-enriched spheres. For the realization, the volume of 28Si-enriched spheres is measured by optical interferometry. The sphere surface characterization by X-ray photoelectron spectroscopy and ellipsometry is also performed. The relative standard uncertainty of the realization is estimated to be 2.4 × 10−8. Details of the realization and future dissemination of mass standards in Japan based on the 28Si-enriched spheres are described.

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“…After the change in the definition of the kilogram, the NMIJ interferometer will be used to realize the kilogram based on the value of h using the XRCD method [14], [34]. The relative uncertainty of the realization was estimated to be 24 × 10 −9 , corresponding to 24 µg for 1 kg [14].…”

Section: Improvement Of the Interferometermentioning

confidence: 99%

Volume Measurement of a ²⁸Si-Enriched Sphere for a Determination of the Avogadro Constant at NMIJ

Kuramoto

Zhang

Fujita

et al. 2019

IEEE Trans. Instrum. Meas.

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For a determination of the Avogadro constant by the X-ray crystal density method, the volume of a Si sphere manufactured from a Si crystal isotopically enriched in 28 Si, named Si28-23Pr11, was measured at the National Metrology Institute of Japan (NMIJ). The volume was determined on the basis of diameter measurement in 2175 directions by an optical interferometer. The surface layers on the sphere were characterized by X-ray photoelectron spectroscopy and spectroscopic ellipsometry. Taking into account the effect of the surface layers on the diameter measurement, the volume of the Si core excluding the surface layers was determined with a relative uncertainty of 2.0 × 10 −8 . The results were used to determine the Avogadro constant in 2017 by the International Avogadro Coordination project, which was used as an input datum to determine the CODATA 2017 adjusted value of the Planck constant h. This h value will be used in the new definition of the kilogram. This paper provides details of the measurement apparatus and the uncertainty analysis of the Si core volume measurement. In addition, an approach to reduce the uncertainty in the Si core volume determination is proposed for the accurate realization of the kilogram based on the new definition at NMIJ. Details of the approach are also provided.

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A comparison of future realizations of the kilogram

Cited by 26 publications

References 11 publications

Avogadro constant measurements using enriched²⁸Si monocrystals

Avogadro constant measurements using enriched²⁸Si monocrystals

Realization of the New Kilogram Using 28Si-Enriched Spheres and Dissemination of Mass Standards at NMIJ

Volume Measurement of a ²⁸Si-Enriched Sphere for a Determination of the Avogadro Constant at NMIJ

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A comparison of future realizations of the kilogram

Cited by 26 publications

References 11 publications

Avogadro constant measurements using enriched28Si monocrystals

Avogadro constant measurements using enriched28Si monocrystals

Realization of the New Kilogram Using 28Si-Enriched Spheres and Dissemination of Mass Standards at NMIJ

Volume Measurement of a 28Si-Enriched Sphere for a Determination of the Avogadro Constant at NMIJ

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Product

Resources

About

Avogadro constant measurements using enriched²⁸Si monocrystals

Avogadro constant measurements using enriched²⁸Si monocrystals

Volume Measurement of a ²⁸Si-Enriched Sphere for a Determination of the Avogadro Constant at NMIJ