  We investigate Venus Express (VEX) observations of magnetic field
fluctuations performed systematically in the solar wind at 0.72 Astronomical
Units (AU), between 2007 and 2009, during the deep minimum of the solar cycle
24. The Power Spectral Densities (PSD) of the magnetic field components have
been computed for the time intervals that satisfy data integrity criteria and
have been grouped according to the type of wind, fast and slow defined for
speeds larger and respectively smaller than 450 km/s. The PSDs show higher
levels of power for the fast than for the slow wind. The spectral slopes
estimated for all PSDs in the frequency range 0.005-0.1 Hz exhibit a normal
distribution. The average value of the trace of the spectral matrix is -1.60
for fast solar wind and -1.65 for slow wind. Compared to the corresponding
average slopes at 1 AU, the PSDs are shallower at 0.72 AU for slow wind
conditions suggesting a steepening of the solar wind spectra between Venus and
Earth. No significant time variation trend is observed for the spectral
behavior of both slow and fast wind.
