Gravity, Geodesy and Fundamental Physics with BepiColombo’s MORE Investigation

open40siThe Mercury Orbiter Radio Science Experiment (MORE) of the ESA mission BepiColombo will provide an accurate estimation of Mercury’s gravity field and rotational state, improved tests of general relativity, and a novel deep space navigation system. The key experimental setup entails a highly stable, multi-frequency radio link in X and Ka band, enabling two-way range rate measurements of 3 micron/s at nearly all solar elongation angles. In addition, a high chip rate, pseudo-noise ranging system has already been tested at 1-2 cm accuracy. The tracking data will be used together with the measurements of the Italian Spring Accelerometer to provide a pseudo drag free environment for the data analysis. We summarize the existing literature published over the past years and report on the overall configuration of the experiment, its operations in cruise and at Mercury, and the expected scientific results.openIess L.; Asmar S.W.; Cappuccio P.; Cascioli G.; De Marchi F.; di Stefano I.; Genova A.; Ashby N.; Barriot J.P.; Bender P.; Benedetto C.; Border J.S.; Budnik F.; Ciarcia S.; Damour T.; Dehant V.; Di Achille G.; Di Ruscio A.; Fienga A.; Formaro R.; Klioner S.; Konopliv A.; Lemaitre A.; Longo F.; Mercolino M.; Mitri G.; Notaro V.; Olivieri A.; Paik M.; Palli A.; Schettino G.; Serra D.; Simone L.; Tommei G.; Tortora P.; Van Hoolst T.; Vokrouhlicky D.; Watkins M.; Wu X.; Zannoni M.Iess L.; Asmar S.W.; Cappuccio P.; Cascioli G.; De Marchi F.; di Stefano I.; Genova A.; Ashby N.; Barriot J.P.; Bender P.; Benedetto C.; Border J.S.; Budnik F.; Ciarcia S.; Damour T.; Dehant V.; Di Achille G.; Di Ruscio A.; Fienga A.; Formaro R.; Klioner S.; Konopliv A.; Lemaitre A.; Longo F.; Mercolino M.; Mitri G.; Notaro V.; Olivieri A.; Paik M.; Palli A.; Schettino G.; Serra D.; Simone L.; Tommei G.; Tortora P.; Van Hoolst T.; Vokrouhlicky D.; Watkins M.; Wu X.; Zannoni M

Gravity, Geodesy and Fundamental Physics with BepiColombo’s MORE Investigation

The Mercury Orbiter Radio Science Experiment (MORE) of the ESA mission BepiColombo will provide an accurate estimation of Mercury’s gravity field and rotational state, improved tests of general relativity, and a novel deep space navigation system. The key experimental setup entails a highly stable, multi-frequency radio link in X and Ka band, enabling two-way range rate measurements of 3 micron/s at nearly all solar elongation angles. In addition, a high chip rate, pseudo-noise ranging system has already been tested at 1-2 cm accuracy. The tracking data will be used together with the measurements of the Italian Spring Accelerometer to provide a pseudo drag free environment for the data analysis. We summarize the existing literature published over the past years and report on the overall configuration of the experiment, its operations in cruise and at Mercury, and the expected scientific results

Proposed antimatter gravity measurement with an antihydrogen beam

The principle of the equivalence of gravitational and inertial mass is one of the cornerstones of general relativity. Considerable efforts have been made and are still being made to verify its validity. A quantum-mechanical formulation of gravity allows for non-Newtonian contributions to the force which might lead to a difference in the gravitational force on matter and antimatter. While it is widely expected that the gravitational interaction of matter and of antimatter should be identical, this assertion has never been tested experimentally. With the production of large amounts of cold antihydrogen at the CERN Antiproton Decelerator, such a test with neutral antimatter atoms has now become feasible. For this purpose, we have proposed to set up the AEGIS experiment at CERN/AD, whose primary goal will be the direct measurement of the Earth's gravitational acceleration on antihydrogen with a classical Moiré deflectometer. © 2007 Elsevier B.V. All rights reserved

Modified Carbon Nanostructures As Catalysts For Oxygen Reduction Reaction

This work is oriented to take advantage of graphene and nanotubes features in electrocatalysis. At present, a main challenge in this context deals with obtaining inexpensive, energetically efficient and durable catalysts for oxygen reduction in Polymer Electrolyte Membrane Fuel Cells (PEMFC). Platinum and Pt-alloys are currently the best cathode catalysts for this reaction. However, since the metal is scarce and expensive, there is a strong effort to find alternative catalysts. Nitrogen-doped carbon catalysts, also containing iron and cobalt centres, appear to be good and promising platinum alternatives1. For outstanding electronic, mechanical and structural properties graphene oxide and nanotubes could be extremely interesting substitutes either as a catalyst itself or as catalyst support. In this work, we will present some preliminary electrochemical results on Oxygen Reduction Reaction about a series of graphene oxide intercalated with polyethyleneimine of different molecular weight2 and doped with iron, and iron doped nitrogen modified nanotubes, prepared using different nitrogen insertion methods. Physico-chemical characterisation will be also presented. 1 F. Jaouen, V. Goellner, M. Lefevre, J. Herranz, E. Proietti, J.P. Dodelet, Electrochim. Acta 87 (2013) 619. 2 T. Tsoufis, F. Katsaros, Z. Sideratou, B.J. Kooi, M.A. Karakassides, A. Siozios, Chem. A Eur. J., In Press, DOI: 10.1002/chem.201304599