Development of HT-6M heterodyne millimeter wave reflectometer

The development of a characteristic heterodyne millimeter wave reflectomete r used for density measurement on nuclear fusion plasma was reported. The i nstrument has high measuring sensitivity and good spatial resolution and in terference resistance by adopting modulation and heterodyne techniques. It offers a new and high precision plasma diagnostic tool for nuclear fusion d evices. The experiments show that the spatial resolution of this reflectome ter is as follows: the poloidal absolute resolution Delta R-p = 0. 7cm, the poloidal relative resolution delta R-p = Delta R-p/R-0 = 1. 08 %, the toro idal absolute resolution Delta L-t = 0. 832cm, the toroidal relative resolu tion delta L-t = Delta L-t/L-0 = 0. 943% (L-0 is the circumference length o f the reflecting layer), the time resolution is about 10 mu s, the measurin g sensitivity delta gamma(c) = 0. 79cm, the relative measuring sensitivity delta gamma(c) = Delta gamma(c/)Ro =1. 22%. The above properties of this re flectometer can meet all needs required by experiments on HT-6M nuclear fus ion device.