Magnetic Fields in Clusters of Galaxies Obtained Through the Study of   Faraday Rotation Measures
  We are developing a new approach to investigate cluster magnetic field strengths and structures. It is based on the comparison of simulated Rotation Measure and radio halo images, obtained from 3-dimensional multi-scale cluster magnetic fields models, with observations. This approach is applied to A2255 in which wide diffuse radio emissions and Rotation Measure images show the evidence of cluster magnetic fields on both large and small scales. 
F. Govoni, L. Feretti, M. Murgia, G.B. Taylor, G. Giovannini, D.   Dallacasa