Electromagnetic Hydrophone with Tomographic System for Absolute Velocity Field Mapping

Pol Grasland-Mongrain (1) , Bruno Gilles (1) , Jean-Martial Mari (1) , Jean-Yves Chapelon (1) , Cyril Lafon (1)

1 LabTAU - Application des ultrasons à la thérapie

The velocity and pressure of an ultrasonic wave can be measured by an electromagnetic hydrophone made of a thin wire and a magnet. The ultrasonic wave vibrates the wire inside a magnetic field, inducing an electrical current. Previous articles reported poor spatial resolution of comparable hydrophones along the axis of the wire. In this study, submillimetric spatial resolution has been achieved by using a tomographic method. Moreover, a physical model is presented for obtaining absolute measurements. A pressure differential of 8% has been found between piezoelectric and electromagnetic hydrophone measurements. These characteristics show this technique as an alternative to standard hydrophones.

Mots clés: Ultrasound; Lorentz force; Pressure field; Hydrophone; Fourier transform; Tomography

Domaines: Acoustique [physics.class-ph]; Physique Médicale [physics.med-ph]; Mécanique des fluides [physics.class-ph]; Electromagnétisme; Acoustique [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Pol Grasland-Mongrain, Bruno Gilles, Jean-Martial Mari, Jean-Yves Chapelon, Cyril Lafon. Electromagnetic Hydrophone with Tomographic System for Absolute Velocity Field Mapping. Applied Physics Letters, 2012, 100 (24), ⟨10.1063/1.4726178⟩. ⟨hal-00700535v2⟩