Wednesday, October 15, 2008

Kan-Chang Wang

Kan-Chang Wang was a nuclear physicist from China. He was one of the initiators of China's researches in nuclear physics, cosmic rays and particle physics. Wang Ganchang figured among the top leaders, pioneers and scientists of the nuclear deterrent program.
Member of the Chinese Academy of Science, and member of the Chinese Communist party.

In 1930, Wang first proposed to use a cloud chamber to study a new type of high-energy rays induced by the bombardment of beryllium with α particle, experiment conducted one year later by the English physicist James Chadwick, thus discovering a new type of particle, the neutron, allowing him to win the 1935 Nobel Prize in Physics.

Wang first proposed the use of beta-capture to detect the neutrino in 1941. Fifteen years later Frederick Reines and Clyde Cowan employed his suggestion and detected the neutrino in 1956 winning forty years later the 1995
Nobel Prize in Physics.

Wang also led a group to discover the particle at Joint Institute for Nuclear Research, Dubna, Russia in 1959.

After May 1950, he became researcher and vice-director of the Institute of Modern Physics . He was vice-director of the Soviet international research centre for nuclear sciences Joint Institute for Nuclear Research . From spring 1969, he was vice-director of the Ninth Research Institute , predecessor of the China Academy of Engineering Physics. He was director of the . He was deputy director of the Nuclear industry Science and Technology Commission . He was second vice-chairman of the China Association for Science and Technology . He was vice-chairman of the Chinese Physical Society . He was first chairman of the China Nuclear Society . He was a member of the third to 16th NPC Standing Committee. He died in 1998.

Early years



Wang Ganchang was born in Changshu City, Jiangsu Province , on May 28, 1907.
In 1924, he graduated from the Shanghai Pudong High School . He then studied English for six months and car driving and repair for six months. He passed the entrance examinations for Qinghua University in August 1928.

He graduated from the Physics Department of Qinghua University in June 1929. He then became assistant professor of Qinghua University from 1929 to 1930. In his thesis "''On the daily change of radon gas''" , he was the first in China to published on atmospheric research and radioactive experiments.

Overseas student in Germany



In 1930 he went to study at the University of Berlin in Germany.
As soon as he arrived in Berlin, hearing the relating the emission of a new type of high-energy neutral radiation which was non-ionizing but even more penetrating than the hardest gamma rays derived from radium, induced by the bombardment of beryllium with α particles from a radioactive polonium source, therefore wrongly presumed to be gamma rays, Wang first suggested the use of a cloud chamber to study it. Lacking the support of his supervisor Lise Meitner, the experiment was nonetheless conducted one year later by the English physicist James Chadwick, thus discovering a new type of particle, the neutron, allowing him to win the 1935 Nobel Prize in Physics.

Four years later in 1934, Wang Ganchang received his with a thesis on β decay spectrum under the supervision of Meitner before returning to China in April of that year.

Return to China



He first joined the Shandong University as a physics professor from 1934 to 1936 before becoming professor at the Zhejiang University and serving as head of the Department of Physics from October 1936 to 1950.

The WW II years



Following the in July 1937, Professor Wang Ganchang was forced to retreat with all the faculty of the Zhejiang University where he was a professor, to the primitive western mountainous hinterland of China.

Enduring difficult conditions, he nonetheless tried in 1939 to find on photographic films tracks of nuclear fission caused by neutron bombardment of cadmium acid.

In 1941, he first proposed an experiment to prove the existence of the neutrino by s in nuclear reactions. Unfortunately, he was unable to implement the experiment because of the war. Fifteen years later Frederick Reines and Clyde Cowan employed his suggestion and detected the neutrino in 1956 winning forty years later the 1995 Nobel Prize in Physics.

Founding of the P.R. China



From April 1950 to 1956 he was a researcher at the CAS Institute of Modern Physics and served as deputy director from 1952. There, at the invitation of Qian Sanqiang of the Institute of Modern Physics, he started studies of cosmic-rays with a circular 12 feet cloud chamber. In 1952, he designed a magnetic cloud chamber.

Professor Wang was the first to propose to established China's first cosmic ray laboratory. Therefore, he directed the Luoxue Mountain Cosmic Rays Research Center in the Yunnan province high mountainous regions at 3185 meters above see level from 1953 to 1956.

His study of cosmic-rays lead him to published in 1955 his findings on neutral-meson decay.
By 1957 he had collected more than 700 recordings of new types of particles.

The USSR years



In order to develop high energy physics in China, the Chinese government began from 1956 to send some experts to the Joint Institute for Nuclear Research at Dubna in the USSR to do field work and carry out the preliminary design of accelerators. The agreement on the establishment of JINR was signed on March 26, 1956 in Moscow, Wang Ganchang being one of the founders.

In April 4, 1956, he went to the USSR to participate in planning the long-range development of peaceful utilization of atomic energy.
Then many students were sent to the former Soviet Union to learn the technologies of how to build accelerators and detectors. Thus, the experimental group lead by Professor Wang Ganchang analysing more than 40,000 photographs which recorded tens of thousands of nuclear interactions taken in the produced by the 10 GeV synchrophasotron used to bombard a target forming high energy mesons, was the first to discover the particles on March 9, 1959:

:\pi^- + C\to \bar\Sigma^- + K^0 + \bar K^0 + K^- + p^+ + \pi^+ + \pi^- + nucleus~~~recoil

The discovery of this new unstable antiparticle wich decays in ·10−10 into an antineutron and a negative pion was announced in September of that year:

Awards



He received the first prize of the ''National Natural Science Award'' in 1982.
He received the first prize of the ''National Science and Technology Progress Award'' in 1985. He received along with Qian Sanqiang both posthumously in September 1999 the special prize of '''' granted by the , the and Central Military Commission .

Selected literature by Wang Ganchang



K. C. Wang (王淦昌). ?ber die obere Grenze des kontinuierlichen β Strahlspektrums von RaE. Zeits. für Physik, 1932,74:744.
Kan Chang Wang. Uber die β-Spektren von ThB+C+C. Zeits für Physik, 1934,87:633.
Kan Chang Wang. A suggestion on the detection of the neutrino. Phys. Rev, 1942,61:97.
K. C. Wang and H. L. Tsao. An attempt at finding the relationship between the nuclear force and the gravitational force. Phys. Rev. 1944, 66:155.

K. C. Wang. A suggestion on a new experimental method for cosmic-ray particles. Science Record, 1945,1:387.
K. C. Wang and T. L. Chiang. On some chemical effects of γ-rays. Science Record, 1945,1:389.
K. C. Wang. Radioactivity of the neutron. Nature, 1945,155:574.
K. C. Wang and K. C. Cheng. A five-dimensional field theory. Phys. Rev. , 1946,70:516.
K. C. Wang. Proposed methods of detecting the neutrino. Phys. Rev. 1947,71:645.
K. C. Wang. An organic activated ZnO-ZnCl2 phosphorescent substance. Science Record, 1947,2:54.
S. C. Hsin and K. C. Wang. Phosphorescence produced by mechanical means. Chinese Journal of Physics, 1947,7 : 53.
Kan-Chang Wang and Stanley B. Jones. On the disintegration of mesotrons. Phys. Rev. 1948,74:1547.
王淦昌.中性介子(π)的发现及它的性质.物理通报,1951,1(1、2):34.
王淦昌,郑仁圻,吕敏.在铅板里发生的电子光子簇射.物理学报,1955,11(5):421.
王淦昌,肖健,郑仁圻,吕敏.一个中性重介子的衰变.物理学报,1955,11(6):493.
郑仁圻,吕敏,肖健,王淦昌.在云室中观察到一个K介子的产生及其核俘获.物理学报,1956,12(4):376.
王淦昌,吕敏,郑仁圻.一个长寿命的带电超子.科学记录(新辑),1957,1(2):21.
Ван Ган-чан и др. исследовавне упр угого pacceяния π Мезонов с импудьсом 6,8 GeV/c на протонах с помошью пропановой пузырь ковойкаме pы. ЖЭТФ, 1960,38:426.
Ван Ган-чан и др. Рожддение Антннротонов при взаимодсйствии π Мезонов с нуклонами. ЖэТФ, 1960,38:1010.
王淦昌,王祝翔,维克斯勒,维辽索夫,乌兰拉,丁大钊等.8.3GeV/c的负π介子所产生的Σ超子.物理学报,1960,16(7):365;ЖэТФ,1960,38:1356.
* 王淦昌,王祝翔,维克斯列尔,符拉娜,丁大钊等.在动量为6.8±6亿电子伏/c的π介子与质子相互作用下A(Σ)及K的产生.物理学报,1961,17(2):61;ЖэТФ,1961,40:464.
* 王淦昌,王祝翔.能量在10GeV以下的π-N,p-N和p-N相互作用.物理学报,1961,17:520.
*H. г. Бирзер, Ван Ган-чан, Ван Цу-чен, динда-цао идр. Неупругие взаимодействия π Мезонов с импульсом 6.8 GeV /c снуклонамц. ЖЭТФ, 1961,41 : 1461.
* 丁大钊,王祝翔,王淦昌.奇异粒子的强相互作用.物理学报,1962,18:334.
王淦昌.利用高功率激光驱动核聚变反应.(内部报告)1964.
王淦昌.国际上惯性约束核聚变情况简介和对我国在这方面工作的意见.(惯性约束核聚变讨论会文集)1982.9.
Wang Naiyan, Wang Ganchang. An 80-GW relativistic electron beam accelerator. Proceedings of the fifth International Conference on High-Power Particle Beams, USA, 1983.
王淦昌,诸旭辉,王乃彦,谢京刚,李鹰山,周昌淮,王璞.6焦耳KrF激光的产生.核科学与工程,1985,5(1):1.
* 王淦昌,诸旭辉,王乃彦,谢京刚,李鹰山,周昌淮,王璞.12.5焦耳电子束泵浦KrF激光器.应用激光,1986,6(2):49.
王淦昌等.王淦昌论文选集.北京:科学出版社,1987.
徐宜志,王淦昌.闪光-1强流脉冲电子束加速器.原子核物理,1987,9(2):69.
N. Wang, G. Wang. 100 Joule level KrF laser pumped by intense electron beam. Proc of the 2nd Int. Workshop on KrF Laser Technology, Alberta, Canada, 1990.

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