Left: Radial distance from the IP of photon conversions in the detector material for different detector configurations in 2010, 2012 and 2015$-$2018. The distributions are obtained for PYTHIA8 simulations and only for photons whose conversion products were reconstructed as clusters in EMCal and formed, when paired with another cluster, a signal in the $\pi^0$ invariant mass window. For 2011 the same number of super modules was installed as in 2012$-$2013, but two fewer modules had the TRD installed in front of them. Right: Neutral pion invariant mass peak position as a function of $p_{\rm T}$ for different magnetic field configurations for pp collisions at $\sqrt{s}=$ 13 TeV.