  Experiments with a liquid metal alloy, galinstan, are reported and show clear
evidence of Alfv\'en wave propagation as well as resonance of Alfv\'en modes.
Galinstan is liquid at room temperature, and although its electrical
conductivity is not as large as that of liquid sodium or NaK, it has still been
possible to study Alfv\'en waves, thanks to the use of intense magnetic fi
elds, up to 13 teslas. The maximal values of Lundquist number, around 60, are
similar to that of the reference experimental study by Jameson [1]. The
generation mechanism for Alfv\'en waves and their refl ection is studied
carefully. Numerical simulations have been performed and have been able to
reproduce the experimental results despite the fact that the simulated magnetic
Prandtl number was much larger than that of galinstan. An originality of the
present study is that a poloidal disturbance (magnetic and velocity fields) is
generated, allowing us to track its propagation from outside the conducting
domain, hence without interfering.
