Replacing the Ur-Kilogram with High-Precision: The new system of units and the precise determination of the defining constants.

Master Seminar *)

For the seminar web-page in the winter term 2020/2021 please flow this link.

*) The seminar is intended for master students (MVSEM), however interested bachelor students (>4th semester) lacking a bachelor seminar (PSEM) could also participate.

Contents:

"Recent decisions of the General Conference on Weights and Measures of the Metre Convention have opened the door to a fundamental change of the International System of Units, the SI, in 2018. The revised SI will be based on fixing the numerical values of seven defining constants corresponding to the seven traditional base units. This will bring about basic modifications in the definition of the kilogram, the ampere, the kelvin, and the mole and will have consequences for units derived from them. In contrast, the second, the meter, and the candela will not be affected.

[...] Benefits and a wide-reaching impact for the realization and dissemination of the units are anticipated because innovative technologies with ever-increasing accuracy will emerge, enabling the direct realization over widespread measurement ranges without the definitions themselves having to be changed." 

[cited from: J. Stenger and J.H. Ullrich, Annu. Rev. Condens. Matter Phys. 2016.7:35-59. ]

The seminar will discuss the new definition of the SI units and the precise determination of the defining constants. The following topics will be discussed:

• 15/11: Intrduction to the revised SI system (PBM und JS)
• 22/11: The Second and the hyperfine transition in Cs (Max Ackermann, UU)
• 29/11: The Meter and speed of light  (Mard Botz, PBM)
• 06/12: The Mole and the Avogadro project (Ebbo Krahmer, JS)
• 13/12: The Kilogram and the Planck constant (Denise Hoffmann, UU)
• 20/12: The Ampere and the elementary charge (Eduard Gevorkjan, JS)
• 17/01: The Kelvin and the Boltzmann constant  (Philipp Dauer, PBM)
• 24/01: The Candela and the luminous efficacy of radiation (Lorenz Michl, NN)

Comprehensive reviews of all seminar topics are available online in Annalen der Physik,Volume 531, Issue 5, Special Issue: The Revised SI: Fundmental Constants, Basic Physics and Units
and PTB Mitteilungen 2016 Heft 2

Lecturer:

Prof. P. Braun-Munzinger (PBM) , Prof. J. Stachel (JS), Prof. U.Uwer (UU)

Dates and venue:

The seminar takes place on Fridays, 11:15 - 13:00, in room INF 226 01.109 (Glas Box).

Practice groups

• Group 1 (Stachel, Uwer)
  7 participants
  INF 226, Konferenzrraum 01.106, Fri 11:15 - 13:00

Material

• Waage.pdf