A high resolution spectroscopic diagnostic for the measurement of the spatial profile of toroidal rotation velocity (v) and temperature (T) of carbon ions has been developed and implemented on the Aditya-U tokamak. The diagnostic consists of a high resolution 1 m (/8.7) spectrometer having an 1800 grooves/mm grating coupled with a charged couple device. The setup allows measurements from 5 toroidal lines-of-sights passing through different minor radii in the horizontal mid-plane of the Aditya-U tokamak. The carbon line emissions at 529 nm in visible and 229.6 and 227.09 nm in the ultra violet spectral range are recorded using the setup. Initial results show that typical Aditya-U plasmas have a maximum carbon ion temperature (T) of ∼120 eV and a rotation velocity (v) of ∼-14 km/s in the counter plasma-current direction.
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http://dx.doi.org/10.1063/1.5039333 | DOI Listing |
Rev Sci Instrum
December 2024
Institute for Plasma Research, Bhat, Gandhinagar 382 428, India.
Poloidal asymmetries in neutral and impurity ion temperatures and particle and impurity transports have been observed in many tokamaks. To investigate these asymmetries, space-resolved visible spectroscopic diagnostic of the ADTIYA-U tokamak has been upgraded to measure the spatial profile of Hα and impurities spectral line profile, ion temperature, and plasma rotation from both low and high field sides of the plasma, simultaneously with a better spatial resolution. This has been done by developing a linear array of 15 optical fibers as compared to the present linear array of nine fibers having a core diameter of 400 μm and coupling it to the entrance slit of a 1 m long high-resolution spectrometer of the existing diagnostic.
View Article and Find Full Text PDFSci Rep
November 2023
Department of Physics, Pandit Deendayal Energy University, Raisan, Gandhinagar, 382 007, India.
Sci Rep
September 2023
Department of Physics, Pandit Deendayal Energy University, Raisan, Gandhinagar, 382 007, India.
We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar line emissions at 472.
View Article and Find Full Text PDFRev Sci Instrum
November 2022
Institute for Plasma Research, Bhat, Gandhinagar 382428, India.
Nascent observations about the influence of kinetic instabilities on electron cyclotron emission (ECE) from runaway electrons (REs) have been detected and explored at the Aditya-Upgrade (Aditya-U) tokamak. The developed broadband ECE radiometer system offers wideband measurements by integrating several radio frequency units with a fixed intermediate frequency receiver with multiple channels, which is a novel approach to meet the needs of the localized measurements at various toroidal fields and extend the system dynamic range. The low density (n ≤ 1 × 10 m) plasma discharges at Aditya-U are consistently accompanied by a 20%-40% increase in the ECE radiometer signal amplitude within 100 µs and sporadic step-like modulations.
View Article and Find Full Text PDFRev Sci Instrum
November 2022
Institute for Plasma Research (IPR), Bhat, Gandhinagar 382428, India.
A Fast Visible Imaging Diagnostic (FVID) system, measuring the visible light emission spectrum (400-1000 nm) from tokamak plasma, has been installed on the Aditya-U tokamak to monitor the two-dimensional dynamics of the poloidal cross section of the plasma. In this work, we present the design and installation of the FVID system on the Aditya-U tokamak. The evolution of plasma and plasma-wall interactions is described.
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