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Seismo-electromagnetic phenomena in porous media arise from seismic wave-induced fluid motion in the pore space, which perturbs the equilibrium of the electric double layer. This paper describes with details the original experimental apparatus built within the ultra-shielded chamber of the Low Noise Underground Laboratory of Rustrel (France). We measured seismo-magnetic conversions in moist sand using two induction magnetometers, and a pneumatic seismic source to generate the seismic wave propagation. We ensured to avoid the magnetometer vibrations, which could induce strong disturbances from induction origin. Interpretation of the data is improved by an analytical description of phase velocities for fast ( P f) and slow longitudinal modes, transverse mode ( S) as well as the extensional mode due to the cylindrical geometry of the sample. The purpose of this paper is to provide elements to measure correctly coseismic seismomagnetic fields and to specify their amplitude. The seismic arrivals recorded in the sample showing a 1200–1300 m s−1 velocity have been associated to P and extensional waves. The measured seismo-magnetic arrivals show a velocity of about 800 m s−1 close to the calculated phase velocity of S waves. Therefore, we show that the seismo-magnetic field is associated to the transverse part of the propagation, as theoretically predicted by Pride (1994) , but never measured up to now. Moreover, the combined experimental and analytical approaches lead us to the conclusion that the measured seismo-magnetic field is probably about 0.035 nT for a 1 m s−2 seismic source acceleration (0.1 g). [ABSTRACT FROM AUTHOR]

The hardware commissioning of the Large Hadron Collider required the testing and the qualification of the cryogenic and vacuum system, as well as the electrical systems for the powering of more than 10 000 superconducting magnets. Nonconformities had to be resolved within a tight schedule. In this paper, we focus on the role that electromagnetic-field computation has played during hardware commissioning in terms of the analysis of a magnet quench and electromagnetic-force calculations in busbars and splices, as well as field-quality prediction for the optimization of powering cycles. [ABSTRACT FROM AUTHOR]