AWARDEE OF PHYSICS PRIZE

ZHANG HUANQIAO

Zhang Huanqiao, nuclear physicist, was born in Chongqing in December 1933. He has been worked at the China Institute of Atomic Energy (CIAE) since his graduation from the Technical Physics Department of Peking University in 1956. He is a research professor and the Director of the Beijing Tandem Accelerator Nuclear Physics National Laboratory in CIAE. He is a part-time professor of Peking University, a concurrent senior adviser of the Science and Technology Committee of China National Nuclear Industry Group Corporation and a member of the Expert Consultative Committee of the Commission of Science and Technology Industry for National Defense. Also he is a member of the Standing Council of the Chinese Physics Society. He was elected the academician of the Chinese Academy of Science in 1997.
Zhang Huanqiao is mainly engaged in experimental researches on neutron physics, nuclear fission and heavy-ion reactions, etc. He joined the construction of the first neutron crystal spectrometer and the first neutron diffractometer in China. He made a research which discovered the phenomenon of the enhancement of neutron diffraction intensity in the vibrating piezoelectric quartz crystal and gave a theoretical explanation in 1960. He measured important nuclear data and built several experimental facilities for national defense. He systematically studied the average number   of neutrons per fission and its correlation with mass, charge and total kinetic energy of fission fragments for the spontaneous fission and neutron induced fission. The measured   (252Cf) value has been used as a primary standard datum for the set of “thermal neutron constants and the neutron yield of the 252Cf spontaneous fission” in the world, which is the only datum from China. Together with his colleagues, he has obtained a series of new results in near- and sub-barrier complete fusion-fission (CFF) reactions. It was found for the first time that the anomalous anisotropy of fragments of the CCF reactions is common phenomenon at near- and sub-barrier energies and that the anomalous bump exists in the variation of the fragment anisotropy with the incident energy for the systems such as 19F, 16O +232Th. Based on these studies, a new model of K pre-equilibrium fission was proposed, which can well explain the observed anomalous anisotropy. The recent experimental result from JAERI supports this model. His work has promoted the development of this kind of research in the world. He has participated in the international collaboration research with INFN-LNL group in the studies of the average angular momentum excitation functions and fusion barrier distributions for the near- and sub-barrier fusion reactions. They observed the three peaks in the fusion barrier distribution for the first time, which displays the structure characteristic of strong double phonon coupling. It indicates the influence of complex surface vibrations on the fusion of 58Ni + 60Ni. This research becomes the classical work in this field. In recent years, using the transfer angular distribution as a probe and developing ANC method to investigate the stable nuclei excited state neutron halo for the first time, they observed the single neutron halo states in the first and second states of 12B and the first excited state of 13C. In this way, the research field on halo nuclei is extended.
Zhang has published over 100 papers and presented 16 invited talks in the international conferences and the symposiums. He was awarded 3rd class the National Natural Science Prize for two times (in 1982 and 1999) and a number of other scientific prizes.