  In this study we examine the radial dependence of the inertial and
dissipation range indices, as well as the spectral break separating the
inertial and dissipation range in power density spectra of interplanetary
magnetic field fluctuations using {\it Parker Solar Probe} data from the fifth
solar encounter between $\sim$0.1 and $\sim$0.7 au. The derived break
wavenumber compares reasonably well with previous estimates at larger radial
distances and is consistent with gyro-resonant damping of Alfv\'enic
fluctuations by thermal protons. We find that the inertial scale power law
index varies between approximately -1.65 and -1.45. This is consistent with
either the Kolmogorov (-5/3) or Iroshnikov-Kraichnan (-3/2) values, has a very
weak radial dependence with a possible hint that the spectrum becomes steeper
closer to the Sun. The dissipation range power law index, however, has a clear
dependence on radial distance (and turbulence age), decreasing from -3 near 0.7
au (4 days) to -4 [$\pm$0.3] at 0.1 au (0.75 days) closer to the Sun.
