Magnetic environment and experiments on-board LISA Pathfinder

Several effects can contribute as force noise on the inertial masses and, amongst them, magnetically-induced forces are precisely one of the effects limiting the performance of the instrument in the milliHertz band. The origin of this disturbance is the coupling of the residual magnetisation and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this term of the noise model, a set of coils and magnetometers are integrated as a part of the LISA Pathfinder diagnostics subsystem.

In this talk, we will explain which are the different magnetic experiments we have carried on board LISA Pathfinder in order to extract the magnetic parameters that characterise LISA Pathfinder's test masses. Moreover, we will also give a complete overview of which was the magnetic field on-board the satellite during mission operations and the effects it had on the mission performance. We will finally describe how, by analysing the movement of the test masses during magnetic experiments, we can extract not only information about their magnetic properties but also about the environment that surrounds them. We also provide the magnetic contribution to the LISA Pathfinder noise budget.