Conceptual design of high resolution and reliable density measurement system on helical reactor FFHR-d1 and demonstration on LHD. (25th August 2015)

• Record Type: Journal Article
• Authors: Akiyama, T.; Yasuhara, R.; Tanaka, T.; Isobe, M.; Sakamoto, R.; Goto, T.; Kawahata, K.; Nakayama, K.; Okajima, S.; Sagara, A.
• Is Part Of: Nuclear fusion. Volume 55:Number 9(2015:Sep.)
• Publication Date: 2015-08-25
• Subjects: demo reactor -- helical device -- density measurement -- dispersion interferometer -- polarimeter; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/55/9/093032
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: This paper describes a conceptual design of the density measurement system on the helical reactor FFHR-d1 based upon its quantitative operation scenario. The density measurement is necessary to satisfy the reactor design, and to have a high density resolution of the order of 10 17 m −3 with a time resolution of 10 ms. High reliability that avoids measurement failures is also necessary. A combined system of 'a dispersion interferometer' and a polarimeter is designed and a prototype of the dispersion interferometer with an Nd:YAG laser is tested. The dispersion interferometer with a CO2 laser is also installed on LHD, which can realize a demo relevant density plasma. The prototypes demonstrate the feasibility on a demo reactor.