Determining the Avogadro Constant from Electrical Measurements

Taylor, Barry N.

doi:10.1088/0026-1394/31/3/004

Cited by 41 publications

(38 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this paper, we report the determination of α deduced from the ratio h/m Rb [9,10,11]. Indeed, the fine structure constant can be related to the ratio h/m X [12] by:…”

Section: Introductionmentioning

confidence: 99%

Precise determination of h/mRb using Bloch oscillations and atomic interferometry: A mean to deduce the fine structure constant

Cadoret

Mirandes

Cladé

et al. 2008

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

Abstract. We use Bloch oscillations to transfer coherently many photon momenta to atoms. Then we can measure accurately the ratio h/m Rb and deduce the fine structure constant α. The velocity variation due to the Bloch oscillations is measured thanks to Raman transitions. In a first experiment, two Raman π pulses are used to select and measure a very narrow velocity class. This method yields to a value of the fine structure constant α −1 = 137.035 998 84 (91) with a relative uncertainty of about 6.6 ppb. More recently we use an atomic interferometer consisting in two pairs of π/2 pulses. We present here the first results obtained with this method.

show abstract

“…In this paper, we report the determination of α deduced from the ratio h/m Rb [9,10,11]. Indeed, the fine structure constant can be related to the ratio h/m X [12] by:…”

Section: Introductionmentioning

confidence: 99%

Precise determination of h/mRb using Bloch oscillations and atomic interferometry: A mean to deduce the fine structure constant

Cadoret

Mirandes

Cladé

et al. 2008

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

show abstract

“…This is clearly demonstrated in Table I, which lists six of the constants whose values are limited by the uncertainty of this measurement and lists the values assumed for other constants needed in the calculations. The equations used to relate these constants to h can be found in [6]. Because this measurement provides the most accurate connection between at atomic constant and the kilogram, the last artifact standard in the International System of Units (SI), it provides an improvement in the assigned uncertainties of all atomic fundamental quantities that are dependent on the kilogram, as well as providing a means of monitoring any changes in the kilogram.…”

mentioning

confidence: 99%

Accurate Measurement of the Planck Constant

et al. 1998

View full text Add to dashboard Cite

Using a moving coil watt balance, electric power measured in terms of the Josephson and quantum Hall effects is compared with mechanical power measured in terms of the meter, kilogram, and second. We find the Planck constant h 6.626 068 91͑58͒ 3 10 234 J s. The quoted standard uncertainty (1 standard deviation estimate) corresponds to ͑8.7 3 10 28 ͒h. Comparing this measurement to an earlier measurement places an upper limit of 2 3 10 28 ͞yr on the drift rate of the SI unit of mass, the kilogram. [S0031-9007(98)

show abstract

“…Avogadro's number NA is the ratio of the SI and atomic units of mass [7]. The unified atomic mass unit is defined by setting the atomic mass of 12 C to be exactly 12.…”

Section: A Molar Planck Constantmentioning

confidence: 99%

Single ion mass spectrometry and the fine structure constant

Pritchard

Bradley²,

Porto³

et al. 2001

AIP Conference Proceedings

View full text Add to dashboard Cite

Using a Penning trap single ion mass spectrometer, we have measured the atomic masses of 13 isotopes, many important for fundamental metrology and fundamental constants. The accuracy of the measurements, w 10~~1 0 , is typically two orders of magnitude better than previously accepted values. A wide variety of self consistency checks greatly reduces the possibility of unknown systematic errors. As part of a program to determine the Molar Planck constant N^h and the fine structure constant a, we measured the masses of 133 Cs, 87)85 Rb, and 23 Na. Our high accuracy atomic mass measurements can be combined with values of h/m atom from atom interferometry measurements and accurate wavelength measurements for different atoms to give several independent determinations of N^h and a. This route to a through N^h, the atomic mass of the proton M p , the electron to proton mass ratio m e /m p , and the Rydberg constant R<^ is based on simple physics. It can potentially achieve the several ppb accuracy needed to test the QED determination of a extracted from measurements of the electron g factor.

show abstract

Determining the Avogadro Constant from Electrical Measurements

Cited by 41 publications

References 53 publications

Precise determination of h/mRb using Bloch oscillations and atomic interferometry: A mean to deduce the fine structure constant

Precise determination of h/mRb using Bloch oscillations and atomic interferometry: A mean to deduce the fine structure constant

Accurate Measurement of the Planck Constant

Single ion mass spectrometry and the fine structure constant

Contact Info

Product

Resources

About