SG-II Facility: the 9th Beam System：
SG-II Multi-function High Power Laser System (SG-II the 9th Beam System) as a surppotive system in SG-II Facility, was under construction from the end of 2002 to 2005, and bagan operation in the same year with its complemetion. Its highest output energy is 5.2kJ/3ns at basic harmonic frequency，with both the second and the third harmoc frequency transfer efficiencies over 60%. Apart from as a driven laser beam with a relatively higher energy, SG-II the 9th Beam can also offer positive diagnoses for physical experiements, providing a comprehensive and precise undersanding the physical status of plasma, thereby a quantative congnition of physical processes and laws.