|
|
AWARDEE OF PHYSICS PRIZE
CHEN JIAER
Abstract
Chen Jia'er, a physicist,the academician of the Chinese Academy of Sciences, was born on October 1, 1934 in Shanghai. He worked in Peking University after graduated from Jilin University. As a visiting scholar, he did research work at the Rutherford Laboratory and Oxford University, U.K, during 1963-1966, and at the State University of New York at Stony Brook and the Institute of Laurence-Berkeley, U.S.A. during 1982-1984. He has been a professor of Peking University since 1984 and was the President of the University from 1996 to 1999. Now he is the President of the National Natural Science Foundation of China (NSFC), the President of Chinese Physical Society, the Chairman of Beijing Association of Science and Technology and Member of the Executive Committee of the Presidium of the Chinese Academy of Sciences. Chen has been working in the field of particle accelerators at Peking University since 1958. With his scientific insights, skills and hard working, Chen has made outstanding contributions in China to catch up frontiers of particle accelerators in the world. 1.Research on the beam physics in the central region of the Rutherford Variable Energy cyclotron. A complete picture and understanding on the process of beam loss in the first ten of orbits were obtained and the gap-crossing resonance that features the Sector Focused Cyclotrons of a three-fold symmetry was identified. By optimizing the related parameters he successfully increased the beam transport efficiency by a factor of more than three. 2. The construction of Peking University's Van de Graaff Accelerator Project. He and his team designed the machine according to their own ideas which led to a sound structure with high stability and uniformed distribution of electrostatic field. Based on an EN Tandem transferred from Oxford, Chen and his team, in 1980s, built up the Peking University Accelerator Mass Spectrometry (PKUAMS) which is the first users' AMS facility for radiocarbon dating in China. The machine sensitivity reaches 4×10-15 with a precision of better than 0.5%. PKUAMS played a key role in accomplishing the national major project entitled “Xia-Shang-Zhou Dynasty's Chronology" under Chen's supervision and efforts. 3. He developed a two-dimensional theory on the beam pulsing and transporting process and designed a high efficiency bunching system using a Helix resonator. During his visiting SUNY at Stony Brook, he made substantial contributions to the design, simulation and commissioning of the high-energy beam pulsing system for the SUNYLAC, and developed a computer software to control the linac and beam transport system. The colleagues there called it “Chen mode" operation, which has been in use essentially in the original form till now. 4. The construction of a Radio Frequency Quadrupoles (RFQ) Accelerator. The 1MeV RFQ for ion implantation was successfully developed at PKU. It accelerates oxygen beam to 1 MeV with an input power of 24 kW at a duty factor as high as 16.7%. Chen and his team designed and demonstrated experimentally, for the first time, the feasibility of simultaneous acceleration of positive and negative ions in one RFQ accelerator. 5. RF superconducting linear accelerator. Chen and his team set up the first RF superconductivity laboratory in China. He and his team successfully developed a surface processing procedure, designed and constructed two 1.5GHz superconducting cavities for accelerating high brightness electron beam using China-made niobium. The peak surface field of these cavities exceeded 20 MV/m. Meanwhile, a 144MHz Nb-Cu sputtered Quarter Wave Resonator QWR (β=0.12) was completed with the maximum field gradient of 6MV/m. As the 1st superconducting proton energy booster in China, it runs steadily on the beam line at a field level of 3 MV/m.
|
|