BEPC II linac beam commissioning and operation

The BEPC II injector linac upgrade goal aims at higher beam energy with smaller beam emittance and energy spread to meet the colliding luminosity upgrade by two orders of magnitude. This paper describes the beam commissioning and operation. The beam energy, energy spread, current, transmission and emittance have met the design goal. The beam orbit and energy instabilities have been studied and a steady beam operation has been realized.