XIAN Dingchang, a theoretical physicist and an expert in synchrotron radiation instrumentation and application passed away in

XIAN's funeral was held on April 11 at the Babaoshan Cemetery in Beijing （image by IHEP）

Beijing on April 7. He was 79. XIAN's funeral was held on April 11 at the Babaoshan Cemetery in Beijing and was attended by his colleagues, friends and students.

XIAN Dingchang was born in 1935 in Guangzhou, Guangdong Province. After graduating from the Technical Physics Department of Peking University in 1956, he joined the research group led by Prof. Zhu Hongyuan on particle theory and quantum field theory at the Institute of Modern Physics, Chinese Academy of Sciences. 

During 1959-1964, he worked at the Joint Institute for Nuclear Research, Dubna, USSR on strong interaction, asymptotic behavior of scattering amplitudes and symmetry theory. In 1965 he assisted Prof. Zhu Hongyuan in developing the “Straton Model" of hadrons. 

XIAN moved in the field of SR instrumentation and application in 1984, successfully led the construction of the first SR facility in China in 1989, since then the facility has been continuously serving as a unique experimental platform for the vast users' community. He engaged in applying SR in various fields, among them: the SR X-ray photoacoustic theory in solids and experiment, application of SR to the research of archaeology and cultural relics, application of SR as a nondestructive tool to paleontology research. 

XIAN was elected the academician of the Chinese Academy of Sciences in 1991, and fellow to the Third World Academy of Sciences in 2002. He was granted the State Prize of Progress in Science and Technology (extraordinary grade) in 1989, the Physics Award from Hong Kong-based Ho Leung Ho Lee (HLHL) Foundation in 2002 and from some other State and Chinese Academy of Sciences prizes.