Finalized design of LHAASO electromagnetic particle detector

LHAASO will lay 5242 electromagnetic particle detectors (EDs) in an area of 1 square kilometer above sea level at 4410m. ED will be used to detect the arrival time and particle number density of secondary electromagnetic particles in the extensive air showers which are generated by the primary cosmic rays and gamma rays with an energy range from 10TeV to 100PeV. This paper mainly introduces the finalized design of ED, including the design of structures, long-term stability and consistency, as well as the test results of EDs built in batches.