UKAEA Papers

"Long Pulse EBW Start-Up Experiments in MAST"

• V.F. Shevchenko
• Y.F. Baranov
• T. Bigelow
• J.B. Caughman
• S. Diem
• C. Dukes
• P. Finburg
• J. Hawes
• C. Gurl
• J.Griffiths
• J. Mailloux
• M. Peng
• A.N. Saveliev
• Y. TakaHe
• H. Tanaka
• G. Taylor

Start-up technique reported here relies on a double mode conversion (MC) for electron Bernstein wave (EBW) excitation. It consists of MC of the ordinary (0) mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X) mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma,…

"TWO-DIMENSIONAL STUDIES OF ELECTRON BERNSTEIN WAVE EMISSION IN MAST"

• V. F. Shevchenko
• M. De Bock
• S. J. Freethy
• A. N. Saveliev
• R. G. L. Vann

Angular scanning of electron Bernstein wave emission (EBE) has been conducted in MAST. From EBE measurements over a range of viewing angles, the angular position and orientation of the B-X-O mode conversion (MC) window can be estimated, giving the pitch angle of the magnetic field in the MC layer. The radial position of the corresponding MC layer i…

"L-H transition and pedestal studies on MAST"

• H. Meyer
• M.F.M De Bock
• N.J. Conway
• S.J Freethy
• K. Gibson
• J. Hiratsuka
• A. Kirk
• C.A. Michael
• T. Morgan
• R. Scannell
• G. Naylor
• S. Saarelma
• A.N Saveliev
• V.F. Shevchenko
• W. Suttrop
• D. Temple
• R.G.L. Vann
• The Mast
• Nbi Teams

"Current Drive and Plasma Heating by Electron Bernstein Waves in MAST"

• V. Shevchenko
• A. Saveliev

Electron Bernstein waves (EBW) have the potential to provide highly localized heating and current drive (CD). EBWs are predominantly electrostatic and they damp on electrons near electron cyclotron harmonics without momentum injection into the plasma. These features represent a powerful tool for understanding transport and stability phenomena by lo…

"Electron Bernstein Wave Studies in MAST"

• V. Shevchenko
• G. Cunningham
• A. Gurchenko
• E. Gusakov
• B. Lloyd
• M. O’Brien
• A. Saveliev
• A. Surkov
• F.Volpe
• M. Walsh

There is a comprehensive, closely-interlinked electron Bernstein wave (EBW) programme on MAST covering heating experiments, plasma start-up studies, plasma emission measurements, theory and modelling. In this paper we report on proof-of-principle EBW heating experiments conducted on MAST with a 60 GHz, 1 MW gyrotron complex. A 28 GHz (200 kW) EBW s…

"DEVELOPMENT OF ELECTRON BERNSTEIN WAVE RESEARCH IN MAST"

• V. Shevchenko
• G. Cunningham
• A. Gurchenko
• E. Gusakov
• B. Lloyd
• M. O’Brien
• A. Saveliev
• A. Surkov
• F. Volpe
• M. Walsh

Burning plasma spherical tokamaks (STs) rely on off-axis current drive (CD) and nonsolenoid start-up techniques. Electron Bernstein waves (EBWs) may provide efficient off-axis heating and CD in high-density ST plasmas. EBWs may also be used in the plasma start-up phase because EBW absorption and CD efficiency remain high even in relatively cold pla…

"Generation of Noninductive Current by Electron-BernsteinWaves on the COMPASS-D Tokamak"

• V. Shevchenko
• Y. Baranov
• M. O’Brien
• A. Saveliev

Electron-Bernstein waves (EBW) were excited in the plasma by mode converted extraordinary ( X ) waves launched from the high field side of the COMPASS-D tokamak at different toroidal angles. It has been found experimentally that X -mode injection perpendicular to the magnetic field provides maximum heating efficiency. Noninductive currents of up to…