EDP Sciences Journals List
Home Document
Subscriber Authentication Point
Issue Eur. Phys. J. Appl. Phys.
Volume 32, Number 3, December 2005
Page(s) 167 - 175
Section Magnetism and Superconductivity
DOI 10.1051/epjap:2005074
Published online 26 October 2005

Eur. Phys. J. Appl. Phys. 32, 167-175 (2005)
DOI: 10.1051/epjap:2005074

Magnetic compensation of gravity forces in liquid/gas mixtures: surpassing intrinsic limitations of a superconducting magnet by using ferromagnetic inserts

L. Quettier1, 2, H. Félice1, 2, A. Mailfert3, D. Chatain4 and D. Beysens4

1  GREEN, INPL-Nancy, 2 Av. de la Forêt de Haye, 54516 Vandoeuvre, France
2  SACM, CEA-Saclay, 91191 Gif-sur-Yvette, France
3  LEM, INPL-Nancy, 2 Av. de la Forêt de Haye, 54516 Vandoeuvre, France
4  SBT, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex, France

lionel.quettier@cea.fr

(Received: 17 September 2004 / Received in final form: 25 April 2005 / Accepted: 9 August 2005 / Published online: 26 October 2005)

Abstract
Magnetic compensation of gravity forces, similar to the space conditions of "microgravity", needs the production of a uniform magnetic force field. We derive here a basic mathematical result that shows the impossibility to establish exact gravity compensation in a finite volume. The imperfection of compensation can be, however, quantified and a relation is derived between homogeneity accuracy and compensation volume in a cylindrical symmetry. We study how the use of inserts made of saturated ferromagnetic materials can modify the homogeneity of magnetic force field. In order to illustrate this result, an iron insert has been numerically calculated for the particular case of gravity compensation of H2 in a 10 T superconducting coil. An experimental test has been carried out on a H2 vapour bubble very close to its gas-liquid critical point. Near the critical point the gas-liquid interfacial tension is vanishing, then any bubble deformation from the ideal spherical shape reveals the non-homogeneities in the magnetic compensation force.

PACS
85.70.Rp - Magnetic levitation, propulsion and control devices.
84.71.Ba - Superconducting magnets; magnetic levitation devices.
64.60.Fr - Equilibrium properties near critical points, critical exponents.
68.03.-g - Gas-liquid and vacuum-liquid interfaces.

© EDP Sciences 2005


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.