Details

Autor(en) / Beteiligte

• Puglia, P.
• Pires de Sa, W.
• Blanchard, P.
• Dorling, S.
• Dowson, S.
• Fasoli, A.
• Figueiredo, J.
• Galvão, R.
• Graham, M.
• Jones, G.
• Perez von Thun, C.
• Porkolab, M.
• Ruchko, L.
• Testa, D.
• Woskov, P.
• Albarracin-Manrique, M.A.

Titel

The upgraded JET toroidal Alfvén eigenmode diagnostic system

Ist Teil von

• Nuclear fusion, 2016-11, Vol.56 (11), p.112020

Ort / Verlag

IAEA: IOP Publishing

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The main characteristics of toroidal Alfvén eigenmodes (TAEs) have been successfully investigated in JET (Joint European Torus) using the scheme of sweeping-frequency external excitation with tracking of the synchronously-detected resonances. However, due to technical limitations, only modes with low values of the toroidal mode number n⩽7 could be effectively excited and unambiguously identified by the Alfvén Eigenmode Active Diagnostic (AEAD) system. This represents a serious restriction because theoretical models indicate that medium-n Alfvén eigenmodes (AEs) are the most prone to be destabilized by energetic particles in ignited plasmas and, therefore, reliable measurement of their damping rates remains a relevant issue to properly access their effect in ignited plasmas. For this reason, a major upgrade of the AEAD system has been carried out aiming at providing a state-of-the-art excitation and real-time detection system for the planned DT campaign in JET. This required the development of a new type of radio frequency amplifier and filter, not commercially available, and also a control system. In this paper, details of the concepts that are relevant to understand the operation of the new system in the next experimental campaigns are presented, as are the results of numerical simulations to model its performance.