This is a 70MeV electron linear accelerator (linac). Originally built in 1967 as the low-energy section of a 300MeV electron linear accelerator, it was later refurbished as a dedicated accelerator to supply high-intensity electron beams to the first experimental room after the earthquake. It consists of a transport line that includes eight 1-meter-long S-band accelerating tubes and a 90-degree beam deflection section. The electron beam transported to the first experimental room is extracted through a titanium window, converted into gamma rays by a converter, and used for experiments such as radioisotope (RI) production and radiochemistry. In addition, in 2020, a new beamline (ULQ2) for precise proton radius measurements using the primary beam was established.。

The distinctive feature of this electron accelerator is its capability to generate high-intensity electron beams, with an average current of up to 150 microamperes and an average beam power exceeding 5 kilowatts. It has a track record of operation in the electron beam energy range of 10 to 60 MeV.