  Low Gain Avalanche Detectors (LGADs) are a type of thin silicon detector with
a highly doped gain layer. LGADs manufactured by Fondazione Bruno Kessler (FBK)
were tested before and after irradiation with neutrons. In this study, the
Inter-pad distances (IPDs), defined as the width of the distances between pads,
were measured with a TCT laser system. The response of the laser was tuned
using $\beta$-particles from a 90Sr source. These insensitive "dead zones" are
created by a protection structure to avoid breakdown, the Junction Termination
Extension (JTE), which separates the pads. The effect of neutron radiation
damage at \fluence{1.5}{15}, and \fluence{2.5}{15} on IPDs was studied. These
distances are compared to the nominal distances given from the vendor, it was
found that the higher fluence corresponds to a better matching of the nominal
IPD.
