Poloidal Rotation and Edge Ion Temperature Measurements Using Spectroscopy Diagnostic on Aditya-U Tokamak

Gaurav Shukla,Ranjana Manchanda,Kajal Shah,Kumarpalsinh A Jadeja,Rakesh L Tanna,Nandini Yadava,Joydeep Ghosh,Malay B Chowdhuri,Balamurali Krishna Mayya K

doi:10.3390/atoms7030093

Gaurav Shukla, Ranjana Manchanda + Show 7 more

Open Access

https://doi.org/10.3390/atoms7030093

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Abstract

The impurity ion poloidal rotation and ion temperature from the Aditya-U tokamak plasma have been measured using a high-resolution spectroscopic diagnostic. It comprises of a high resolution, 1 m, f/8.7, Czerny-Turner configuration spectrometer along with charge coupled device (CCD) detector. The system monitors the spectral line emission of C2+ impurity ions at 464.74 nm from the top port of the Aditya-U vacuum vessel with the lines of sight covering the plasma minor radius from r = 11.55 cm to 21.55 cm. The impurity ion poloidal rotation velocity and temperature have been estimated using the Doppler shift and Doppler broadening of the spectral lines respectively. The maximum poloidal rotation at a radial location of 21.55 cm in the edge of the plasma during the plasma current flat top was observed to be ~4 km/s for the analyzed discharges and the ion temperatures measured in the edge were in the range of 32–40 eV.

Highlights

Plasma rotation plays an important role in understanding the momentum transport and its effect on improved confinement and stabilizing resistive wall modes, suppressing magneto-hydrodynamic (MHD) instabilities and turbulence through E × B shear [1,2]
This paper presents the first measurement of the impurity poloidal rotation in the Aditya-U
A high-resolution spectroscopic diagnostic [32] was used for the measurements of impurity ion poloidal rotation velocity and the edge ion temperature using the Doppler shift and Doppler broadening of the spectral line emission respectively

Summary

Introduction

Plasma rotation plays an important role in understanding the momentum transport and its effect on improved confinement and stabilizing resistive wall modes, suppressing magneto-hydrodynamic (MHD) instabilities and turbulence through E × B shear [1,2]. The measurements of both the toroidal and poloidal rotation in Aditya-U tokamak are crucial to obtain the radial electric field profile which in turn can provide insight into the E × B shearing rate. A high-resolution spectroscopic diagnostic [32] was used for the measurements of impurity ion poloidal rotation velocity and the edge ion temperature using the Doppler shift and Doppler broadening of the spectral line emission respectively. This diagnostic has been developed to study both the toroidal and poloidal plasma rotation using UV and visible spectral lines from various ionization stages of carbon impurity [33].

Experimental Set up and Analysis Technique

Experimental Results

Summary