Nature of magnetic fluctuations in CASTOR tokamak

Summary form only given. The magnetic fluctuations are monitored in radial and poloidal directions deep (upto r/a=0.4) into the tokamak. The magnetic fluctuations are studied near the core of the tokamak with the magnetic probes. For carrying out these experiments different sets of movable probes, which could move from r/a=1 to r/a=0.4, were used. A set of two movable poloidal probes, which are poloidally spaced from each other, were taken up to r/a=0.4 for observing the poloidal field fluctuations near the core of the CASTOR. The radial profile of the poloidal magnetic fluctuations level is obtained from r/a=1 to r/a=0.4. The correlation values and poloidal wavenumber are also obtained at different radial positions. Two movable sets, each of two probes, were installed for registering the radial magnetic field fluctuations. In one set the probes were toroidally spaced and each was facing the radial magnetic field of the tokamak. The data from these toroidally spaced radial probes tells the behaviour of radial magnetic field fluctuations in the toroidal space. The correlation and wavenumber values are compared. In the other set the radial magnetic probes were poloidally spaced from each other. This time poloidal wavenumber and correlation values are obtained at different radial positions and compared particularly for two cases, r/a=1 and r/a=0.4.