Precise determination of the ratioh/mu: a way to link microscopic mass to the new kilogram

Cladé, Pierre; Biraben, F.; Julién, L.; Nez, F.; Guellati-Khélifa, Saïda

doi:10.1088/0026-1394/53/5/a75

Cited by 28 publications

(22 citation statements)

References 42 publications

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“…For most chemicals, variability of isotopic abundances must also be considered for high-accuracy work. Therefore, an additional relative uncertainty of 1 part in 10 9 can be neglected [41][42][43]. The experimental uncertainty of M u in the proposed new SI was discussed following eq.…”

Section: Consequences For Chemistry Of the Cgpm Resolutionsmentioning

confidence: 99%

“…The quantity m u /h is a physical constant with the SI unit m −2 s. It has been measured to high accuracy in two different types of atomic-physics experiments [42,43]. In fact, the relative uncertainty of m u /h is far smaller than the relative uncertainty (parts in 10 8 ) to which N can presently be determined.…”

Section: Crystal Density Approach or Atom Countingmentioning

confidence: 99%

See 1 more Smart Citation

A critical review of the proposed definitions of fundamental chemical quantities and their impact on chemical communities (IUPAC Technical Report)

Marquardt

Meija

Mester

et al. 2017

Pure and Applied Chemistry

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Abstract:In the proposed new SI, the kilogram will be redefined in terms of the Planck constant and the mole will be redefined in terms of the Avogadro constant. These redefinitions will have some consequences for measurements in chemistry. The goal of the Mole Project (IUPAC Project Number 2013-048-1-100) was to compile published work related to the definition of the quantity 'amount of substance', its unit the 'mole', and the consequence of these definitions on the unit of the quantity mass, the kilogram. The published work has been reviewed critically with the aim of assembling all possible aspects in order to enable IUPAC to judge the adequateness of the existing definitions or new proposals. Compilation and critical review relies on the broadest spectrum of interested IUPAC members.

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Section: Consequences For Chemistry Of the Cgpm Resolutionsmentioning

confidence: 99%

Section: Crystal Density Approach or Atom Countingmentioning

confidence: 99%

A critical review of the proposed definitions of fundamental chemical quantities and their impact on chemical communities (IUPAC Technical Report)

Marquardt

Meija

Mester

et al. 2017

Pure and Applied Chemistry

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“…Using rigorous relations between fundamental physical constants [24], the mass of an electron is expressed as where h is the Planck constant, R ∞ is the Rydberg constant, c is the speed of light in vacuum, and α is the fine-structure constant. N A is therefore related to h as …”

Section: Principle Of the Xrcd Methodsmentioning

confidence: 99%

“…Another relation between N A and h can be derived from the ratio h/m(X) for an atom X, which can be determined by atom recoil measurements using atom interferometry [24]. Thus, the Planck constant can also be determined using the following equation:…”

Section: Principle Of the Xrcd Methodsmentioning

confidence: 99%

Realization of the kilogram by the XRCD method

Fujii¹,

et al. 2016

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When the kilogram is redefined in terms of the fixed numerical value of the Planck constant h, the x-ray-crystal-density (XRCD) method, among others, is used for realizing the redefined kilogram. The XRCD method has been used for the determination of the Avogadro constant N A by counting the number of atoms in a 28 Si-enriched crystal, contributing to a substantial reduction of uncertainty in the values of N A and h to 2 parts in 10 8 . This method can be therefore used reversely for the mass determination of a 1 kg sphere prepared from the crystal. This is realized by SI-traceable measurements of its lattice parameter, isotopic composition, volume, and surface properties. Details of the corresponding measurements are provided, as well as the concept of the XRCD method, isotope enrichment, crystal production, sphere manufacturing, and evaluation of impurities and self-point defects in the crystal, together with mass comparison with respect to the silicon sphere for disseminating mass standards.

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“…The coefficient R ∞ /( c α 2 ) is known with a relative uncertainty below 1 × 10 −9 , which is negligible for the Planck constant determination . Lately, a new, more direct method became available which uses the recoil of atoms due to the absorption of photons …”

Section: X‐ray Crystal Density Methodsmentioning

confidence: 99%

The Planck Constant for the Definition and Realization of the Kilogram

Wood

Bettin

2018

Annalen der Physik

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On May 20, 2019 the values of the Planck, h, and Avogadro, N A , constants will be fixed, revising our measurement system, the International System of Units (SI), and providing a new way to get mass traceability. While the famous energy relations mc 2 and hf may remind many that the Planck constant is indeed related to mass, it is less recognized how this is also true for the Avogadro constant. These concepts are reviewed in the context of the upcoming revision of the SI. How the fixed values were chosen and how mass traceability will be maintained with the smallest uncertainty are also discussed.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/andp.201800308 ν Cs = 9 192 631 770 Hz hyperfine transition frequency of 133 Cs c = 299 792 458 m s −1 speed of light in vacuum h = 6.626 070 15 × 10 −34 J s Planck constant e = 1.602 176 634 × 10 −19 C elementary charge k = 1.380 649 × 10 −23 J K −1 Boltzmann constant N A = 6.022 140 76 × 10 23 mol −1 Avogadro constant K cd = 683 lm W −1 luminous efficacy of 540 × 10 12 Hz radiationThe values and use of c, ν Cs , and K cd are already established within the SI and this has made the change more manageable.

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Precise determination of the ratioh/m_u: a way to link microscopic mass to the new kilogram

Cited by 28 publications

References 42 publications

A critical review of the proposed definitions of fundamental chemical quantities and their impact on chemical communities (IUPAC Technical Report)

A critical review of the proposed definitions of fundamental chemical quantities and their impact on chemical communities (IUPAC Technical Report)

Realization of the kilogram by the XRCD method

The Planck Constant for the Definition and Realization of the Kilogram

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