Multiparameter measurement utilizing poloidal polarimeter for burning plasma reactor

Abstract

The authors have made the basic and applied research on the polarimeter for plasma diagnostics. Recently, the authors have proposed an application of multiparameter measurement (magnetic field, B, electron density, n e , electron temperature, T e , and total plasma current, I p ) utilizing polarimeter to future fusion reactors. In this proceedings, the brief review of the polarimeter, the principle of the multiparameter measurement and the progress of the research on the multiparameter measurement are explained. The measurement method that the authors have proposed is suitable for the reactor for the following reasons; multiparameters can be obtained from a small number of diagnostics, the proposed method does not depend on time-history, and far-infrared light utilized by the polarimeter is less sensitive to degradation of of optical components. Taking into account the measuring error, performance assessment of the proposed method was carried. Assuming that the error of Δθ and Δε were 0.1 • and 0.6 • , respectively, the error of reconstructed j φ , n e and T e were 12 %, 8.4 % and 31 %, respectively. This study has shown that the reconstruction error can be decreased by increasing the number of the wavelength of the probing laser and by increasing the number of the viewing chords. For example, By increasing the number of viewing chords to forty-five, the error of j φ , n e and T e were reduced to 4.4 %, 4.4 %, and 17 %, respectively.

Characterization Measurements of Sapphire and Diamond based KIDs for Polarimetric Plasma Diagnostics

“…The response time is orders of magnitudes above the typical dynamics of Cooper pairs generation-recombination and more in line with a bolometric regime. The detectors nevertheless fulfill the International Thermonuclear Experimental Reactor (ITER) response time guidelines of 10 ms [13] that have been taken into consideration during the design phase. We also checked the response of the pixels to radiation of two orthogonal polarizations.…”

Real-time pedestal optimization and ELM control with 3D fields and gas flows on DIII-D

“…Such schemes can become significantly more complex when recycling and pumping are taken into account using models [46] or even more complex when aiming for fully predictive profile control [47]. Towards ITER and future demonstration power plants, which also will have line integrated n e measurements [48][49][50], the main actuator will become deuterium (D) and tritium (T) pellet injection systems [51].…”

Diagnostics and control for the steady state and pulsed tokamak DEMO

“…The electron temperature has an effect on these measurements since the dielectric tensor depends on the electron temperature: So from these measurements an evaluation of the electron temperature can be carried out. The measurement of temperature can be extracted using an equilibrium code: An accuracy of 30% in the determination of Te was evaluated in [28].…”

“…This measurement is done by interferometrypolarimetry systems in the present day machines. In the ITER both toroidal [27] and poloidal [28] interferometer/polarimeters are planned. The experience on the toroidal interfero-polarimeter (TIP) was done on the tokamak JT-60U, where a dual wavelength (λ = 10.6 μm and 9.27 μm) CO 2 toroidal interfero-polarimeter [29] was extensively tested for the measurement of electron line integrated density using Faraday rotation.…”

“…The measurement of temperature can be extracted using an equilibrium code: An accuracy of 30% in the determination of Te was evaluated in [28].…”