We recently set up a time-resolved optical beam diagnostic system. Using this system,we measured the high current electron beam energy in the accelerator under construction. This paper introduces the principle of the diagnostic system,describes the setup,and shows the results. A bending beam line was designed using an existing magnetic analyzer with a 300 mm-bending radius and a 60° bending angle at hard-edge approximation. Calculations show that the magnitude of the beam energy is about 18 MeV,and the energy spread is within 2%. Our results agree well with the initial estimates deduced from the diode voltage approach.
