73 research outputs found
On the problems of creating a nuclear-optical frequency standard based on 229Th
The most probable candidate for the role of a nuclear optical standard is the
8.338-eV isomer of the 229mTh isotope of the thorium nucleus. Ways of using the
resonance properties of the electron shell as an optical resonator to create
laser-nuclear technologies necessary for the optical pumping of nuclear isomers
and other manipulations of atomic nuclei leading to the creation of a
next-generation frequency standard and nuclear-optical clocks based on them are
discussed. Deep relations between the physics of resonance electron-nuclear
interactions and the true solution of the thorium puzzle are shown. The article
discusses important principles of resonant optical pumping, such as the
presence of a finite width in the intermediate electronic state, and others
that are usually overlooked with a fatal result for the experiment. The wide
application of the various physics of these processes will predetermine a
revolutionary leap in the development of new laser-nuclear technologies.Comment: 9 pages, 3 figures, submitted to the Proceedings of KVNO-202
Self-attraction effect and correction on three absolute gravimeters
The perturbations of the gravitational field due to the mass distribution of
an absolute gravimeter have been studied. The so called Self Attraction Effect
(SAE) is crucial for the measurement accuracy, especially for the International
Comparisons, and for the uncertainty budget evaluation. Three instruments have
been analysed: MPG-2, FG5-238 and IMPG-02. The SAE has been calculated using a
numerical method based on FEM simulation. The observed effect has been treated
as an additional vertical gravity gradient. The correction (SAC) to be applied
to the computed g value has been associated with the specific height level,
where the measurement result is typically reported. The magnitude of the
obtained corrections is of order 1E-8 m/s2.Comment: 14 pages, 8 figures, submitted to Metrologi
Proposal for new experimental schemes to realize the Avogadro constant
We propose two experimental schemes to determine and so to realize the
Avogadro constant at the level of 10 or better with a watt
balance experiment and a cold atom experiment measuring (where is
the Planck constant and the mass of the atom ). We give some
prospects about achievable uncertainties and we discuss the opportunity to test
the existence of possible unknown correction factors for the Josephson effect
and quantum Hall effect
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