The irony of the magnet system for Kibble balances—a review

Li, Shisong; Schlamminger, Stephan

doi:10.1088/1681-7575/ac464a

Cited by 10 publications

(8 citation statements)

References 70 publications

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“…This Bl factor (also called "force factor") in the actual Kibble balance experiment is determined through the force and velocity modes, eqs. ( 5) and ( 6), and compared with each other at the level of several parts in 10 −8 for mass values at 1 kg level [31], unlike the table-top versions [7], [21] where the required precision in determination and consistency in comparison is at ppm level for example for 1 g mass.…”

Section: Design Of the System And Developed Measurement Infrastructurementioning

confidence: 99%

Deploying the high-power pulsed lasers in precision force metrology -- SI traceable and practical force quantization by photon momentum

Vasilyan¹,

Fröhlich²,

Rogge³

2022

Preprint

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Design and operational performance of table-top measurement apparatus is presented towards direct Planck constant traceable high accuracy and high precision small forces and optical power measurements within SI unit system. An electromagnetic force compensation weighing balances, highly reflective mirrors and high-energy pulsed laser unit (static average power 20 W) are tailored together with a specially developed opto-electro-mechanical measurement infrastructure for cross-mapping the scale-systems of precision small force measurements obtained with a state-of-the-art classical kinematic system employing Kibble balance principle in the range of 10 nN to 4000 nN in comparison with forces generated due to quantum-mechanical effect namely the transfer of the momentum of the photons from a macroscopic object. Detailed overview of the adapted measurement methodology, the static and the limits of dynamic measurement, the metrological traceability routes of the measurement parameters, quantities and their measurement uncertainties, parametric up(down)-scaling perspectives of the measurements are presented with respect to the state-of-theart measurement principles and standard procedures within the newly redefined International System of Units (SI).

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Section: Design Of the System And Developed Measurement Infrastructurementioning

confidence: 99%

Deploying the high-power pulsed lasers in precision force metrology -- SI traceable and practical force quantization by photon momentum

Vasilyan¹,

Fröhlich²,

Rogge³

2022

Preprint

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“…A historical overview is given in [6]. In the past two decades, however, a clear favorite has emerged.…”

Section: A Comparison Of Two Magnet Systemsmentioning

confidence: 99%

Calculation of magnetic forces and torques on the Kibble coil

Schlamminger¹,

Keck²,

Chao³

et al. 2022

Preprint

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Analytically the force acting on a current-carrying coil in a magnetic field can be calculated one of two ways. First, a line integral can be conducted along the coil's wire, summing up the differential force contributions. Each contribution results from a cross-product of the corresponding differential line segment with the magnetic flux density at that location. Alternatively, the coil's energy in the field is given as a product of three factors, the number of turns, the current, and the flux threading the coil. The energy can then be obtained by executing a surface integral over the coil's open surface using the scalar product of the differential surface element with the magnetic flux density as its integrand. The force on the coil is the negative derivative of the energy with respect to the appropriate coordinate. For yoke-based Kibble balances, the latter method is much simpler since most of the flux is contained in the inner yoke of the magnet and can be written as a simple equation. Here, we use this method to provide simple equations and their results for finding the torques and forces that act on a coil in a yoke-based magnet system. We further introduce a straightforward method that allows the calculation of the position and orientation difference between the coil and the magnet from three measurements.

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“…[9][10][11][12][13][14]. A historical overview is given in [6]. In the past two decades, however, a clear favorite has emerged.…”

Section: A Comparison Of Two Magnet Systemsmentioning

confidence: 99%

“…The physics is the same, regardless of whether the derivative of the flux or the geometric factor is used to describe the situation. Appendix A in [6] shows how the derivative of a surface integral (flux) can be converted into a line integral with Green's theorem for a divergence-free field. Gauss's law ensures that the divergence of the flux density is zero, i.e., ∇ • B = 0.…”

Section: Introductionmentioning

confidence: 99%

Calculation of magnetic forces and torques on the Kibble coil

et al. 2022

Self Cite

View full text Add to dashboard Cite

Analytically the force acting on a current-carrying coil in a magnetic field can be calculated in two ways. First, a line integral can be conducted along the coil's wire, summing up the differential force contributions. Each contribution results from a cross-product of the corresponding differential line segment with the magnetic flux density at that location. Alternatively, the coil's energy in the field is given as a product of three factors, the number of turns, the current, and the flux threading the coil. The energy can then be obtained by executing a surface integral over the coil's open surface using the scalar product of the differential surface element with the magnetic flux density as its integrand. The force on the coil is the negative derivative of the energy with respect to the appropriate coordinate. For yoke-based Kibble balances, the latter method is much simpler since most of the flux is contained in the inner yoke of the magnet and can be written as a simple equation. Here, we use this method to provide simple equations and their results for finding the torques and forces that act on a coil in a yoke-based magnet system. We further introduce a straightforward method that allows the calculation of the position and orientation difference between the coil and the magnet from three measurements.

show abstract

The irony of the magnet system for Kibble balances—a review

Cited by 10 publications

References 70 publications

Deploying the high-power pulsed lasers in precision force metrology -- SI traceable and practical force quantization by photon momentum

Deploying the high-power pulsed lasers in precision force metrology -- SI traceable and practical force quantization by photon momentum

Calculation of magnetic forces and torques on the Kibble coil

Calculation of magnetic forces and torques on the Kibble coil

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