Design of an infrared/visible endoscope system for HL-3 divertor observation

Abstract This paper presents the design and test results of an infrared/visible endoscope system for diagnosing divertor in HL-3 tokamak. The system is designed to view the plasmas tangentially with multi-imaging systems including two infrared imaging systems and three visible imaging systems. Several filters based visible imaging measurements are thus available simultaneously for divertor physics investigation. The performance of the optical design is explored, and the manufacture of the system and the test results are presented. The characteristics of the advanced divertor configurations, such as multi-strike points and two X-points, are observed clearly with the endoscope system.