Verification of real-time polarization-controlled microwave reflectometry for magnetic field vector profile measurement

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14525
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: The University of Tokyo
• Principal Investigator: INOMOTO Michiaki 東京大学, 大学院新領域創成科学研究科, 准教授 (00324799)
• Co-Investigator(Renkei-kenkyūsha): TOKUZAWA Tokihiko 核融合科学研究所, ヘリカル研究部, 准教授 (90311208)
• Research Collaborator: KAWAMORI Eiichirou
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: プラズマ計測 / 核融合 / マイクロ波反射計

Outline of Final Research Achievements

A novel polarization-controlled microwave reflectometry was proposed to measure the internal magnetic field profiles of fusion core plasmas. A full wave calculation code was developed and quantitative assessment for mode conversion was carried out on one- and two- dimensional geometries. The control part to rotate the polarization angle was fabricated using variable gain amplifiers and phase shifters. The amplitude of two input waves for a dual polarized antenna was quickly changed within 4 micro seconds, resulting in a control frequency of up to 100 kHz. In order to adjust the polarization angle with the magnetic field on the plasma surface, the modified Cauchy Condition Surface method was employed to reconstruct the last closed flux surface with high accuracy while large eddy current was induced on the vessel wall. These results showed high feasibility for the proposed polarization-controlled microwave reflectometry.

Free Research Field

プラズマ理工学