Ionic liquid ferrofluid electrospray with EMIM-NTf2 and ferrofluid mode studies with FerroTec EFH-1 in a non- uniform magnetic field

An electrospray ion source was operated using a newly designed ionic liquid ferrofluid based on the ionic liquid EMIM-NTf2. The magnetic properties of the fluid were exploited to create self-assembling array of peaks on the fluid surface, which were then amplified using an electric field, eventually causing ions to be emitted from the tip of each peak in the instability. A beam current of 72 micro-Amps was measured from a five-peak array subject to extraction voltage of 2750 V. In a separate experiment, modal patterns in the surface of a ferrofluid subject to a Rosensweig instability were measured in non-uniform fields created by permanent magnets. These measured wavelengths were shown to agree well with a hypothesis put forth by Rupp where the magnetic force is treated similarly to the gravitational force in the classical dispersion relation.