. 2D grayscale images of neutrons (top row) and X-ray (bottom row) of the pristine graphite anode as reconstructed and after the different filtering was applied sequentially. The outer circle corresponds to the glass capillary that was used to house the anode. The graphite anode and the copper current collector are indistinguishable in the neutron images whereas the copper current collector is visible clearly in the X-ray images. The grayscale bar on the right has arbitrary units (a.u.) and was created using 32-bit images in ImageJ.