摘要
A broadband frequency tunable microwave reflectometer system, which has the abil- ity of fast and stable frequency sweeping operation, is applied in the large helical device （LHD） to measure the boundary of the high-temperature plasma. When the microwave is launched, with extraordinary polarization, from the low field side of the magnetic field with its frequency swept from low to high, the microwave of minimum right-hand cut-off frequency is reflected most out- side. We can then estimate the plasma boundary position by measuring the change of the reflected power from the cut-off layer.
A broadband frequency tunable microwave reflectometer system, which has the abil- ity of fast and stable frequency sweeping operation, is applied in the large helical device （LHD） to measure the boundary of the high-temperature plasma. When the microwave is launched, with extraordinary polarization, from the low field side of the magnetic field with its frequency swept from low to high, the microwave of minimum right-hand cut-off frequency is reflected most out- side. We can then estimate the plasma boundary position by measuring the change of the reflected power from the cut-off layer.
基金
a Grant-in-Aid for Scientific Research on Priority Areas (Nos.18035015,20026010)
a Grant-in-Aid for Young Scientists (A)(No.18686075)
the Ministry of Education,Culture,Sports,Science and Technology Japan and also a budgetary Grant-in-Aid (No.NIFS08ULHH508)of National Institute for Fusion Science and the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusion
