Optical measurements for turbulence characterization in RFX-mod edge
- Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, 35127 Padova (Italy)
The edge of the reversed field pinch experiment RFX-mod (R=2 m, a=0.46 m) is characterized by a complex magnetic topology and strong pressure gradients. A set of fast spectroscopic diagnostics has been designed to characterize both main plasma edge parameters and turbulence, including coherent structures (blobs) and radial profiles of the thermodynamic variables. Measurements of the edge radial profiles of electron density (n{sub e}), temperature (T{sub e}), and pressure (P{sub e}) are obtained by a thermal helium beam diagnostic, which locally measures the ratios of the spectral lines emitted by a neutral He cloud puffed into hydrogen plasma discharges. A gas puff imaging system allows the high frequency (1 MHz bandwidth) measurement of the fluctuations of He I emissivity in the same positions. The system measures both the intermittent behavior of the edge turbulence and n{sub e}, T{sub e}, and P{sub e} profiles of the corresponding coherent structures, with a resolution down to 6 {mu}s. The optical diagnostics are complemented by a set of triaxial magnetic coils to simultaneously characterize the edge magnetic field.
- OSTI ID:
- 22055802
- Journal Information:
- Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
A multichord soft x-ray diagnostic for electron temperature profile measurements in RFX-mod
A 3D approach to equilibrium, stability and transport studies in RFX-mod improved regimes