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 β-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.
@article{arxiv.2111.12656,
title = {Inter-pad dead regions of irradiated FBK Low Gain Avalanche Detectors},
author = {B. Darby and S. M. Mazza and F. McKinney-Martinez and R. Padilla and H. F. -W. Sadrozinski and A. Seiden and B. Schumm and M. Wilder and Y. Zhao and R. Arcidiacono and N. Cartiglia and M. Ferrero and M. Mandurrino and V. Sola and A. Staiano and V. Cindro and G. Kranberger and I. Mandiz and M. Mikuz and M. Zavtranik and M. Boscardin and G. F. Della Betta and F. Ficorella and L. Pancheri and G. Paternoster},
journal= {arXiv preprint arXiv:2111.12656},
year = {2022}
}