Hanbit microwave plasma diagnostic system

As a part of the plasma diagnostic system for the Hanbit device, various mi crowave plasma diagnostic systems have been designed and developed from the initial stage of the Hanbit project. These include the interferometer, ref lectometer, and electron cyclotron emission radiometer. In this work, we pr esent the current activities related to the development of the microwave di agnostic systems. The brief descriptions of each system are as follows. The probing wave frequency of the interferometer is 94 GHz. Two types of inter ferometer have been developed. One is a conventional heterodyne-type interf erometer with two microwave sources (94 GHz, 94.2 GHz Gunn oscillators). Th e other system uses a heterodyne-type phase detection method with one micro wave source (94 GHz, Gunn oscillator) and a single sideband upconverter. Fo r the plasma density profile measurements, an FM-CW reflectometer with a 7- 18 GHz YIG source will be installed at the Hanbit central cell. If the O-mo de propagation is adopted, it can cover one half portion of the central cel l plasma density profile under the density 5 x 10(12) cm(-3). A heterodyne phase detection method is also used for this reflectometer with a single si deband upconverter. (C) 1999 Elsevier Science S.A. All rights reserved.