F. AharonianQ. AnAxikeguL. X. BaiY. X. BaiY. W. BaoD. BastieriX. J. BiY. J. BiH. CaiJ. T. CaiZ. CaoZ. CaoJ. ChangJ. F. ChangX. C. ChangB. M. ChenJ. ChenL. ChenL. ChenL. ChenM. J. ChenM. L. ChenQ. H. ChenS. H. ChenS. Z. ChenT. L. ChenX. L. ChenY. ChenN. ChengY. D. ChengS. W. CuiX. H. CuiY. D. CuiB. Z. DaiH. L. DaiZ. G. DaiDanzengluobuD. della VolpeB. D’Ettorre PiazzoliX. J. DongJ. H. FanY. Z. FanZ. X. FanJ. FangK. FangC. F. FengL. FengS. H. FengY. L. FengB. GaoC. D. GaoQ. GaoW. GaoM. M. GeL. S. GengG. H. GongQ. B. GouM. H. GuJ. G. GuoX. L. GuoY. Q. GuoY. Y. GuoY. A. HanH. H. HeH. N. HeJ. C. HeS. L. HeX. B. HeY. HeM. HellerY. K. HorC. HouX. HouH. B. HuS. HuS. C. HuX. J. HuD. H. HuangQ. L. HuangW. H. HuangX. T. HuangY. HuangZ. C. HuangF. JiX. L. JiH. Y. JiaK. JiangZ. J. JiangC. JinD. KuleshovK. LevochkinB. B. LiC. LiC. LiF. LiH. B. LiH. C. LiH. Y. LiJ. LiState Key Laboratory of Particle Detection & ElectronicsNanjing UniversityShanghai Astronomical Observatory Chinese Academy of SciencesInstitute for Nuclear Research of the Russian Academy of SciencesShandong UniversityWuhan UniversityYunnan UniversityInstitute of High Energy Physics Chinese Academy of ScienceUniversity of Chinese Academy of SciencesGuangzhou UniversityTsinghua UniversitySun Yat-Sen UniversityUniversity of Science and Technology of ChinaZhengzhou UniversityDublin Institute for Advanced StudiesUniversità degli Studi di Napoli Federico IISichuan UniversityNational Astronomical Observatories Chinese Academy of SciencesMax-Planck-Institut für KernphysikSouthwest Jiaotong UniversityPurple Mountain Observatory Chinese Academy of SciencesUniversité de GenèveHebei Normal UniversityTibet UniversityTIANFU Cosmic Ray Research Center2022-08-042022-08-042021-12-01Radiation Detection Technology and Methods. Vol.5, No.4 (2021), 520-53025099949250999302-s2.0-85114164158https://repository.li.mahidol.ac.th/handle/20.500.14594/76890Purpose: The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. Method: The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. Result and Conclusion: The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.Mahidol UniversityEnergyPhysics and AstronomyArticleSCOPUS10.1007/s41605-021-00275-4