August, 2004

Headline News Basic Research


Information Technology

Life Science

Environmental Protection

Research & Development International Cooperation Visits & Exchanges  
Basic Research

"Probe No. 2" Satellite Launched Successfully :
"Double Star " Sisters Met in the Space

At 18" 5' 15 o'clock of July 25, Beijing time, the " Probe No. 2" satellite was sent into the space successfully by the modified rocket "Long March II C" at the Taiyuan Satellite Launching Centre in China. It is an indication that the "Geospace Double Star Probe Program" being carried out by our country has been achieved successfully. Combined with the "magnetic layer Probe program" of the European Space Bureau, the six points and three-dimensional detection to the geospace were realized for the first time in the human history.

The "Probe No.2" satellite launched this time was jointly developed by the China Space-flight Technology & Science Group Co., Space Science & Application Research Center of CAS and the five European research and development institutions that are coordinated with the European Space Bureau, and it is the 2nd satellite in the "Geospace Double Star Probe Program" of China. The satellite is 343 kg in weight approximately and with a working life of 12 months.

Great Progress Achieved on the HT-7 Superconducting Tokamak Spring Experiment

Big breakthrough was made in the high temperature plasma physics experiments held between Apr. 11 and Jun. 14, 2004. Plasma discharges were maintained for about 240 seconds, breaking the 100 seconds threshold. Abundant and fruitful researches have been conducted.

The physicists worked in five topic groups, including Long Pulse and Steady State Plasma Technology, Core Plasma Confinement and Transport, MHD Analysis and Control, Boundary Plasma and Plasma Surface Interaction. Productive experiments were carried out on sixteen topics, such as Synergy of Low Hybrid Wave and Ion Bernstein Wave, Feedback Control of MHD Activities Under High Power Heating, Turbulence and Boundary Transport, Density Limit and Multifaceted Asymmetric Radiation From the Edge (MARFE), Omegatron Probe, etc. Among all the progress, the greatest breakthrough was made on long pulse operation with low hybrid wave current driving. The maximum pulse duration reached about 240 seconds.

In addition, during this experiment, scientists from National Institute for Fusion Science (Japan), Kyushu University (Japan), Massachusetts Institute of Technology (America) and the University of Texas (America) joined the experiments with their own proposals, data analysis codes or diagnostic systems. The cooperation turns out to be satisfactory.

Research on High Power VCSELs Achieves World-level Results

980nm high power VCSEL, a major research project, undertaken by a cooperative research group with Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), and Institute of Physics, CAS has passed the technical appraisement on May 30, 2004. Committee of experts concluded that the large diameter vertical cavity surface emitting lasers (VCSELs) developed by the group achieved many world-level results.

As explained by Prof. Lijun Wang, VCSELs has many advantages, such as excellent light beam quality and large-scale integration compared with conventional edge-emitting lasers. It was the first time that high thermal conducting Al2O3 film was used as the passivation layer to decrease non-radiation combination and threshold current density. It was also the first time that HfO2-based multi-layer was used as the light emission window. These approaches bring about a breakthrough progress in the research of high power VCSELs. High output power of 1.95W in continuous wave operation was realized for large-diameter VCSELs with diameters of 500mm, 600mm and 700mm. A VCSEL with a diameter of 200mm exhibited an output power as high as 10.5W and a power density of 33.4KW/cm2. A 300mm-diameter VCSEL demonstrated a CW output power of 1.11W with a power density of 1.57KW/cm2. All the results above were higher than other similar devices reported abroad. The lifetime of the devices was beyond 4500 hours.

Other Issues
Fifteenth Issue (Spring 2000)
Sixteenth Issue (Summer 2000)
Seventeenth Issue (Autumn 2000)
Eighteenth Issue (Winter 2000)
Nineteenth Issue (Spring 2001)
Twentith Issue (Summer 2001)
Twenty-first Issue (Autumn 2001)
Twenty-second Issue (Winter 2001)
Twenty-third Issue (Spring 2002)
Twenty-forth Issue (Summer 2002)
Twenty-fifth Issue (Autumn 2002)
Twenty-sixth Issue (Winter 2002)
Twenty-seventh Issue (Spring, 2003)
Twenty-eighth Issue (June, 2003)
Twenty-nineth Issue (August, 2003)
Thirtieth Issue (October, 2003)
Thirty-first Issue (December, 2003)
Thirty-second Issue (February, 2004)
Thirty-third Issue (April, 2004)
Thirty-fourth Issue (June, 2004)

copyright © 1998-2005
CAS Newsletter Editorial Board: 52, Sanlihe Road, Beijing 100864, CHINA