Review of Advanced Implementation of Doppler Backscattering Method in Globus-M

Alexander Yashin,Anna Ponomarenko,Alexander Petrov,Victor Bulanin

doi:10.3390/app11198975

Alexander Yashin, Anna Ponomarenko + Show 2 more

Open Access

https://doi.org/10.3390/app11198975

Copy DOI

Abstract

Doppler backscattering (DBS) is a microwave diagnostics method typically used to study the plasma rotation velocity. Apart from conventional techniques, more advanced forms of DBS implementation were suggested on Globus-M. More specifically the study of a variety of oscillating processes was performed using DBS. In this review we present a detailed description of all of the methods and techniques employed in Globus-M alongside results obtained using DBS in all the years up until the shutdown of the tokamak. These include research similar to that done on other devices into the properties of such phenomena like geodesic acoustic modes or limit cycle oscillations, along with innovative works regarding the detection and investigation of Alfven eigenmodes and filaments that were the first of their kind and that provided important and novel results. Apart from that, the specific aspects of DBS application on a spherical tokamak are discussed. An in-depth look into the gradual change and improvement of the DBS diagnostics on Globus-M is also presented in this paper.

Highlights

Doppler backscattering (DBS) is a microwave diagnostics method applied on many magnetic confinement fusion devices typically with the aim to study the plasma rotation velocity [1,2,3,4,5,6,7,8,9]
The first results show that the perpendicular rotational velocities obtained with DBS are consistent with the estimates of the poloidal rotation obtained from the charge exchange recombination spectroscopy diagnostics
In this review we aim to present a detailed description of all the methods and techniques employed in Globus-M in regard to DBS diagnostics used to study all the various phenomena that occur in plasma during a discharge

Summary

Introduction

Doppler backscattering (DBS) is a microwave diagnostics method applied on many magnetic confinement fusion devices typically with the aim to study the plasma rotation velocity [1,2,3,4,5,6,7,8,9]. In the Globus-M2 tokamak, the first results of the Doppler backscattering diagnostics during a discharge with the L-H transition show that the transition process is linked to the deformation of the poloidal rotation velocity profile [16]. This diagnostic made it possible to conduct studies in the hotter and more central plasma regions, which is a useful addition to the velocity and field data obtained by other methods

Objectives

Methods

Results