  Magnetosonic waves are low-frequency, linearly polarized magnetohydrodynamic
(MHD) waves commonly found in space, responsible for many well-known features,
such as heating of the solar corona. In this work, we report observations of
interesting wave signatures driven by injecting compact toroid (CT) plasmas
into a static Helmholtz magnetic field at the Big Red Ball (BRB) Facility at
Wisconsin Plasma Physics Laboratory (WiPPL). By comparing the experimental
results with the MHD theory, we identify that these waves are the fast
magnetosonic modes propagating perpendicular to the background magnetic field.
Additionally, we further investigate how the background field, preapplied
poloidal magnetic flux in the CT injector, and the coarse grid placed in the
chamber affect the characteristics of the waves. Since this experiment is part
of an ongoing effort of creating a target plasma with tangled magnetic fields
as a novel fusion fuel for magneto-inertial fusion (MIF), our current results
could shed light on future possible paths of forming such a target for MIF.
