Effect of LH and ECR waves on plasma parameters in ADITYA Upgrade tokamak

TL;DR

This paper investigates how LH and ECR waves influence plasma parameters in the ADITYA Upgrade tokamak, highlighting new experimental observations of wave-plasma interactions and their effects on plasma heating and current drive.

Contribution

It reports novel experimental findings on the impact of LH and ECR waves on plasma parameters in ADITYA-U for the first time.

Findings

Observed effects of ECRH on plasma temperature.

Observed effects of LHCD on plasma current.

Reported new wave-plasma interaction phenomena in ADITYA-U.

Abstract

The plasma discharges in ADITYA Upgrade Tokamak are produced by means of transformer action, in which Ohmically created plasma is driven by means of a secondary loop voltage. Due to reduction of plasma resistivity after a certain level of plasma temperature, Ohmic heating becomes poor and further achievement of temperature needs other heating techniques. ADITYA-U tokamak is facilitated with a 42 GHz-500 kW Electron Cyclotron Resonant Heating (ECRH) system. Also, there is a Lower Hybrid Current Drive (LHCD) system installed and operated at 3.7 GHz for driving non-inductive plasma current followed by the Ohmic current drive. Though an eventual impact in the rise of plasma temperature and plasma current due to the application of ECRH and LHCD respectively are very obvious, their energy coupling with the plasma results in several interesting outcomes in a number of experimentally measured plasma parameters. The present work addresses such impactful observations that are noticed and reported for the first time in ADITYA-U Tokamak.