Study of a collimation method as a nondestructive diagnostic diagnostic technique by PGNAA for salt distribution in concrete structures at RANSYasuo Wakabayashi, Takao Hashiguchi, Yuichi Yoshimura, Maki Mizuta, Yujiro Ikeda and Yoshie OtakeEPJ Web Conf., 231 (2020) 05007DOI: https://doi.org/10.1051/epjconf/202023105007