A novel 2D ion temperature measurement for toroidal plasmas has been developed by use of cost-effective discrete tomography reconstruction of 2D ion Doppler spectroscopy composed of a polychromator with an ICCD camera and optical fibres. The 2D projection of the line spectrum collected by 35 (7 × 5) optical fibres is transformed into the r-z profile of the local spectrum by means of the Abel inversion at each wavelength and finally into the 2D (r-z) profile of the ion temperature. Numerical tests of its algorithm indicate that the reconstruction error for a peaked temperature profile is smaller than 15% if the chord-integrated signals have noise smaller than 5%. This system successfully measured the peaked ion temperature profile of a torus plasma on the r-z plane under the condition of negligibly small plasma flow.

A novel 2D toroidal plasma flow velocimetry has been developed using tomographic reconstruction technique. The 2D imaging of local (R-Z) toroidal velocity is achieved by the vector tomographic reconstruction technique and multi-chord 2D spectroscopy by 35-channel optical fiber array. Numerical simulation for reconstruction of bi-directional toroidal velocity profile suggests that the cost-effective arrangement of the optical fiber for a toroidal plane is 7. We installed the system with 7 × 5 chords arrangement to the TS-4 device. This system successfully measured 2D bi-directional toroidal velocity profile around X point with 10% accuracy during the counter-helicity magnetic reconnection experiment.

No abstract

No abstract