The Shashlik tower is a significant component to measure the energy, time, and position of
photons and electrons in the Electromagnetic Calorimeter (ECal), a vital detector of the
Multi-Purpose Detector (MPD) in the Nuclotron-based lon Collider fAcility (NICA), Dubna,
Russia. Based on the GEANT4 simulation toolkit, a variation of physical behavior in the tower was
simulated, including the changes of photons during transmission, and used the rising edge
detection method to measure the time-resolving ability of the module for natural muons and
electron beams. Results show that 3 GeV electrons enter the tower, photons emitted by the
scintillator are transmitted, 10665 photoelectrons are collected on Silicon Multipliers (SiPMs),
yield is 3555 pe/GeV, and the light output is 0.16%. The time resolution of the module for
muons is better than 160 ps, but the value of each tower is different. In addition, by changing
the electron beam energy in the simulation, we observed that a larger number of photoelectrons
collected by SiPMs leads to a better time resolution. At an electron beam energy of 1 GeV, the
time resolution of the tower could be better than 101 ps. The simulated measuring results, and the
methods of the tower photon transmission performance and the time resolution, will provide
references and new optimum methods for subsequent experiential tests.