Multimachine Data-Based Prediction of High-Frequency Sensor Signal Noise for Resistive Wall Mode Control in ITER
Artikel i vetenskaplig tidskrift, 2016

The high-frequency noise measured by magnetic sensors, at levels above the typical frequency of resistive wall modes, is analyzed across a range of present tokamak devices including DIII-D, JET, MAST, ASDEX Upgrade, JT-60U, and NSTX. A high-pass filter enables identification of the noise component with Gaussian-like statistics that shares certain common characteristics in all devices considered. A conservative prediction is made for ITER plasma operation of the high-frequency noise component of the sensor signals, to be used for resistive wall mode feedback stabilization, based on the multimachine database. The predicted root-mean-square n = 1 (n is the toroidal mode number) noise level is 10(4) to 10(5) G/s for the voltage signal, and 0.1 to 1 G for the perturbed magnetic field signal. The lower cutoff frequency of the Gaussian pickup noise scales linearly with the sampling frequency, with a scaling coefficient of about 0.1. These basic noise characteristics should be useful for the modeling-based design of the feedback control system for the resistive wall mode in ITER.

resistive wall mode

Sensor noise

Författare

Yueqiang Liu

Chalmers, Rymd- och geovetenskap, Plasmafysik och fusionsenergi

S. A. Sabbagh

Columbia University in the City of New York

I. T. Chapman

Culham Lab

S. Gerasimov

Culham Lab

Y. Gribov

ITER

T. C. Hender

Culham Lab

V. Igochine

Max Planck-institutet

M. Maraschek

Max Planck-institutet

G. Matsunaga

Japan Atomic Energy Agency

M. Okabayashi

Princeton Plasma Physics Laboratory

E. J. Strait

General Atomics

Fusion Science and Technology

1536-1055 (ISSN)

Vol. 70 3 387-405

Ämneskategorier

Reglerteknik

DOI

10.13182/fst15-207