Example of full resolution (10.7 kpc/pixel) radio halo in the simulated galaxy cluster R1a. Left and right panels refer to the total intensity and polarized surface brightness images, respectively. The bottom panels show the azimuthally averaged radio-halo brightness profiles of the total intensity I (green dots), polarized intensity P (red squares), and fractional polarization FPOL (blue triangles). The profiles have been calculated in concentric annuli, as shown in the inset panel.