Xie Jialin, an expert in accelerator physics and free electron lasers, a recipient of China's top science award and member of Chinese Academy of Sciences (CAS), died on February 20 at the age of 96.

Professor Xie was born in Harbin, Heilongjiang province in August, 1920. He graduated from Yanjing University in 1943 and moved to the United States for further study. At Caltech, Xie obtained his M.S. degree in Physics in 1948, and in 1951 he received his PhD from Stanford University.

From 1951 to 1955, he worked at the microwave and high-energy physics laboratory at Stanford University. He was then in charge of building an accelerator at Michael Reese Hospital in Chicago, which was the highest-energy (45 MeV) medical accelerator in the world at that time.

In 1955, Prof. Xie decided to return to China. Although he faced many difficulties, including a lack of proper equipment and up-to-date information, and even occasionally life-threatening exposure in a dangerous environment, Prof. Xie was determined to go on with his research.

“These difficulties were nothing for someone who wished to achieve something important,” he said. Following successful prefabrication research on various components of an electron linear accelerator, such as an electron gun, accelerating tube, high-power pulse modulator, microwave system and high-power klystron, he built a 30-MeV electron linac in 1964, the first one ever built in China. The successful construction of China’s first high-energy electron linear particle accelerator led to Prof. Xie’s award of the Scientific and Technological Achievement Prize at the National Science and Technology Conference in 1978.

During the 1980s, he headed the design, manufacture and construction of Beijing Electron-Positron Collider Project. He later led the development of Beijing Free Electron Laser. He was elected to CAS in 1980. In 1990, Xie was awarded a Supreme Prize for National Science and Technology Progress.

On learning about the establishment of free electron lasers around the world – the latest development in the field of science and technology – Xie proposed the development of Beijing Free Electron Laser and then worked out a concrete scheme. Using funds provided in 1987 under the State 863 High Tech Program, he succeeded in building China’s first infrared free-electron laser, which produced spontaneous emission in May 1993, the lasing reached saturation at the end of 1993. This was the first infrared free-electron laser built in Asia. In 1994, he was awarded the Supreme Prize for Science and Technology Progress by CAS.

Prof. Xie published over 40 scientific papers and several monographs. He also mentored a great number of accelerator physicists in universities and institutions.

In 2015, the International Astronomical Union announced that Minor Planet No. 32928 had been named after Prof. Xie Jialin to commemorate his outstanding contributions in particle accelerator science. The Institute of High Energy Physics established a Youth Innovation Fund which was named "Xie Jialin Fund."

Prof. Xie Jialin was long at the forefront of China’s high-energy physics and accelerator science and technology research, to which he made a great contribution. He remains a role model for all science and technology workers, and the Xie Jialin star in the sky will keep shining and inspiring us long into the future.

Source: english.cas.cn