1
|
Shen YQ, Yang ZC, Zhong WL, Jiang M, Shi ZB, Santos J, Shi PW, Tong RH, Xue GQ, Zhou Y, Wen J, Yu X, Deng WC, Wang S, Yang ZJ, Chen ZY, Li D, Zha XQ, Jin ZY, Xu X, Xu M. Plasma position measurements by O-mode and X-mode reflectometry systems in tokamak plasmas. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:063505. [PMID: 37862534 DOI: 10.1063/5.0140390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 06/07/2023] [Indexed: 10/22/2023]
Abstract
Plasma Position Reflectometry (PPR) is planned to provide plasma position and shape information for plasma operation in future fusion reactors. Its primary function is to calibrate the drift of the magnetic signals due to the integral nature of magnetic measurement. Here, we attempt to measure plasma position using ordinary mode (O-mode) and extraordinary mode (X-mode) reflectometry systems on two tokamaks. A new physical model based on the phase shift is proposed to deduce the relative movement of the cut-off layer without density inversion. We demonstrate the plasma position measurements by absolute measurement from density profile inversion and relative measurement from phase shift. The combination of X-mode and O-mode reflectometers can minimize the limitations of single polarization reflectometry and further increase the accuracy of plasma position measurement. These results could provide an important technical basis for the further development of a real-time control system based on PPR.
Collapse
Affiliation(s)
- Y Q Shen
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Z C Yang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - W L Zhong
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - M Jiang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Z B Shi
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - J Santos
- Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear-Laboratório Associado, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
| | - P W Shi
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - R H Tong
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - G Q Xue
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
- Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Y Zhou
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - J Wen
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - X Yu
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - W C Deng
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - S Wang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Z J Yang
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Z Y Chen
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - D Li
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - X Q Zha
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Z Y Jin
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - X Xu
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - M Xu
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| |
Collapse
|
2
|
Leppink E, Lau C, Lin Y, Wukitch SJ. Evaluation of the Abel inversion integral in O-mode plasma reflectometry using Chebyshev-Gauss quadrature. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:063506. [PMID: 37862546 DOI: 10.1063/5.0132246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 06/15/2023] [Indexed: 10/22/2023]
Abstract
The Abel transform is often used to reconstruct plasma density profiles from O-Mode polarized reflectometry diagnostics. However, standard numerical trapezoidal evaluation of the Abel inversion integral can be computationally expensive for a large number of evaluation points, and an endpoint singularity exists on the upper-bound of the integral, which can result in an increased error. In this work, Chebyshev-Gauss quadrature is introduced as a new method to evaluate the Abel inversion integral for the problem of O-Mode plasma reflectometry. The method does not require numerical evaluation of an integral singularity and is shown to have similar accuracy compared to existing methods while being computationally efficient.
Collapse
Affiliation(s)
- E Leppink
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Y Lin
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| | - S J Wukitch
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
3
|
Gonçalves B, Varela P, Silva A, Silva F, Santos J, Ricardo E, Vale A, Luís R, Nietiadi Y, Malaquias A, Belo J, Dias J, Ferreira J, Franke T, Biel W, Heuraux S, Ribeiro T, De Masi G, Tudisco O, Cavazzana R, Marchiori G, D’Arcangelo O. Advances, Challenges, and Future Perspectives of Microwave Reflectometry for Plasma Position and Shape Control on Future Nuclear Fusion Devices. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23083926. [PMID: 37112274 PMCID: PMC10142666 DOI: 10.3390/s23083926] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 03/30/2023] [Accepted: 04/06/2023] [Indexed: 06/12/2023]
Abstract
Providing energy from fusion and finding ways to scale up the fusion process to commercial proportions in an efficient, economical, and environmentally benign way is one of the grand challenges for engineering. Controlling the burning plasma in real-time is one of the critical issues that need to be addressed. Plasma Position Reflectometry (PPR) is expected to have an important role in next-generation fusion machines, such as DEMO, as a diagnostic to monitor the position and shape of the plasma continuously, complementing magnetic diagnostics. The reflectometry diagnostic uses radar science methods in the microwave and millimetre wave frequency ranges and is envisaged to measure the radial edge density profile at several poloidal angles providing data for the feedback control of the plasma position and shape. While significant steps have already been given to accomplish that goal, with proof of concept tested first in ASDEX-Upgrade and afterward in COMPASS, important, ground-breaking work is still ongoing. The Divertor Test Tokamak (DTT) facility presents itself as the appropriate future fusion device to implement, develop, and test a PPR system, thus contributing to building a knowledge database in plasma position reflectometry required for its application in DEMO. At DEMO, the PPR diagnostic's in-vessel antennas and waveguides, as well as the magnetic diagnostics, may be exposed to neutron irradiation fluences 5 to 50 times greater than those experienced by ITER. In the event of failure of either the magnetic or microwave diagnostics, the equilibrium control of the DEMO plasma may be jeopardized. It is, therefore, imperative to ensure that these systems are designed in such a way that they can be replaced if necessary. To perform reflectometry measurements at the 16 envisaged poloidal locations in DEMO, plasma-facing antennas and waveguides are needed to route the microwaves between the plasma through the DEMO upper ports (UPs) to the diagnostic hall. The main integration approach for this diagnostic is to incorporate these groups of antennas and waveguides into a diagnostics slim cassette (DSC), which is a dedicated complete poloidal segment specifically designed to be integrated with the water-cooled lithium lead (WCLL) breeding blanket system. This contribution presents the multiple engineering and physics challenges addressed while designing reflectometry diagnostics using radio science techniques. Namely, short-range dedicated radars for plasma position and shape control in future fusion experiments, the advances enabled by the designs for ITER and DEMO, and the future perspectives. One key development is in electronics, aiming at an advanced compact coherent fast frequency sweeping RF back-end [23-100 GHz in few μs] that is being developed at IPFN-IST using commercial Monolithic Microwave Integrated Circuits (MMIC). The compactness of this back-end design is crucial for the successful integration of many measurement channels in the reduced space available in future fusion machines. Prototype tests of these devices are foreseen to be performed in current nuclear fusion machines.
Collapse
Affiliation(s)
- Bruno Gonçalves
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Paulo Varela
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - António Silva
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Filipe Silva
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Jorge Santos
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Emanuel Ricardo
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Alberto Vale
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Raúl Luís
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Yohanes Nietiadi
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Artur Malaquias
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Jorge Belo
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - José Dias
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Jorge Ferreira
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Thomas Franke
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching, Germany
| | - Wolfgang Biel
- Institut für Energie- und Klimaforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Stéphane Heuraux
- Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine, BP 50840, F-54011 Nancy, France
| | - Tiago Ribeiro
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching, Germany
| | | | - Onofrio Tudisco
- ENEA, Fusion and Technologies for Nuclear Safety Department, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Italy
| | | | | | - Ocleto D’Arcangelo
- ENEA, Fusion and Technologies for Nuclear Safety Department, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Italy
| |
Collapse
|