The magnetic diagnostic system (MDS) plays an essential role in the tokamak operations; in fact, it provides the main support in the identification of a number of plasma characteristics critical for the plasma equilibrium and stability control. In order to supervise the reliability of the MDS and to detect possible failures, a procedure has been recently proposed [1] based on two steps: (i) identification of a suitable current distribution able to represent the plasma contribution in the MDS signals by solving an inverse problem; (ii) comparison between the current effect on the probes and actual measurements to look for the discrepancies exceeding the physiological error bar. The equivalent current is described by a scalar stream function, on a fixed toroidal support located in the plasma region, and the function is projected in a finite double Fourier series in toroidal and poloidal spaces. The procedure is rather effective because of both the 3D capabilities and the promptness because widely parallelized. The procedure, successfully assessed in other fusion devices [2], is presently applied to the DTT [3], the Tokamak designed to explore new solutions for the power and particle exhaust control and to test both new divertor concepts and innovative magnetic configurations. Aim of the study is to contribute to the assessment of the DTT MDS robustness and to propose strategies to face with failure scenarios in real time. The paper describes the main result in the DTT robustness and fault analysis also considering possible 3D effects.
Application of the Mirror Procedure to the Robustness and Fault Analysis of Divertor Tokamak Test facility
Terranova David
2020
Abstract
The magnetic diagnostic system (MDS) plays an essential role in the tokamak operations; in fact, it provides the main support in the identification of a number of plasma characteristics critical for the plasma equilibrium and stability control. In order to supervise the reliability of the MDS and to detect possible failures, a procedure has been recently proposed [1] based on two steps: (i) identification of a suitable current distribution able to represent the plasma contribution in the MDS signals by solving an inverse problem; (ii) comparison between the current effect on the probes and actual measurements to look for the discrepancies exceeding the physiological error bar. The equivalent current is described by a scalar stream function, on a fixed toroidal support located in the plasma region, and the function is projected in a finite double Fourier series in toroidal and poloidal spaces. The procedure is rather effective because of both the 3D capabilities and the promptness because widely parallelized. The procedure, successfully assessed in other fusion devices [2], is presently applied to the DTT [3], the Tokamak designed to explore new solutions for the power and particle exhaust control and to test both new divertor concepts and innovative magnetic configurations. Aim of the study is to contribute to the assessment of the DTT MDS robustness and to propose strategies to face with failure scenarios in real time. The paper describes the main result in the DTT robustness and fault analysis also considering possible 3D effects.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
