Yu Wenyan (1937-1989) was a native of Taishan, Guangdong. He graduated from Physics Department of Jilin University in 1959. He had taken on optics and laser study in Changchun Institute of Optics and Fine Mechanics and Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences. He was the developer of China's first Fabry-Perot interferometer and Q-switch ruby laser. Since 1965, he had been studying high power laser and laser fusion for 24 years. He was one of the first to put forward the interaction between broadband laser and matters, which won him CAS Natural Science Award, Second Prize. He was also one of the leaders in developing "Laser-12 Facility" whose output power can reach 1012W (known as "Shenguang" Facility) which won State Scientific and Technological Progress Award, First Class in 1990. He publicized more than 60 theses and reports in optics, intense laser, laser, and interaction between plasma. His innovative ideas in one of his theses titled as "International Development in Laser Nuclear Fusion and Our Countermeasures" would exert profound and lasting influence in future.
INTRODUCTION TO LASER-12 FACILITY
Deng Ximing, Fan Dianyuan and Yu Wenyan
(Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences)
Laser-12 Facility, named "SHEN-GUANG", is the largest Nd. glass laser system in China. The general technical performances of the facility have reached an internationally advanced level in comparing with the similar facilities in the world.
It consists of laser driver subsystem with two beams, high accuracy target chamber, diagnostic subsystem and laboratory environment engineering, etc. The output laser power is up to 1012W for each beam with diameter 200mm and wavelength 1.053 mm. Divergence angle 'of the laser beam is 0.1mrad and pulse rejection (rate of signal to noise) up to 107-108.
The facility is used for experimental research on laser inertial confinement fusion (ICF), X-ray laser, Equation of state of material under high pressure, and other laser plasma physics research at the world frontiers field.
Since the facility was built in 1986, considerable progresses have been made, e.g.:
- In indirect-driven ICF experiments, the radiation temperature inside hohlraum cavity reached 130ev, and neutron 'yield about 104.
- In Ne-like Ge X-ray laser research, using a unique "multi-target series coupling" design, we obtained obvious gain saturation and effective GL values more than 17 for lasing lines 23.2, 23.6 nm respectively. The divergence angle of the X-ray beam is up to 1.5 mrad. It is the best result in the world.
- In equation of state of material measurements, using "lens array "method, a unique target uniform illumination technique, we obtained high shock wave pressure range from 0.4 to 0.8 TPa on Al-Cu impedance match targets. Its shock adiabat is measured accurately. The experimental data are closely in accord with that of the extra-polation both from measurement using high explosive-loading facility (the lower pressure) and underground nuclear test (the higher pressure).
The "Laser-12 Facility" will be upgraded to eight beams facility. Total laser energy will increase to 6kJ (for 1ns), and wavelength range expand to green (0.53 mm) and ultraviolet (0.35 mm).