A MeerKAT view on galaxy clusters
  Almost two decades of observations of radio emission in galaxy clusters have
proven the existence of relativistic particles and magnetic fields that
generate extended synchrotron emission in the form of radio halos. In the
current scenario, radio halos are generated through re--acceleration of
relativistic electrons by turbulence generated by cluster mergers. Although
this theoretical framework has received increasingly supporting observational
evidence over the last ten years, observations of statistically complete
samples are needed in order to fundamentally test model predictions. In this
paper we briefly review our 7--element Karoo Radio Telescope observations of a
sample of nearby clusters aimed to test the predictions of the turbulent
re--acceleration model in small systems ($M_{500} > 4 \times 10^{14}$
M$_{\odot}$). We conclude by presenting two galaxy cluster surveys to be
carried out with MeerKAT in order to provide crucial test of models of radio
halo formation in nearby ($z < 0.1$) and high redshift ($z > 0.4$) systems
respectively.
