Physics performance of the STAR zero degree calorimeter at relativistic heavy ion collider

The zero degree calorimeter （ZDC） at RHIC- STAR was installed in the year 2000. After running for more than 10 years, the performance of the STAR-ZDC cannot maintain a proper status because of the radiation damage. The ZDC on RHIC-BRAHMS had been moved to STAR in 2011 after some tests. We present here the result of the tests as well as the physical performance of those ZDC modules between the 2011 and 2015 RHIC runs. The excellent energy resolution of the ZDC in heavy ion col- lision provides a good candidate for future detector development, such as the CSR experiment at CAS-Lanzhou facility.