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Gonzalez-Martin J, Ayllon-Guerola J, Garcia-Munoz M, Herrmann A, Leitenstern P, De Marne P, Zoletnik S, Kovacsik A, Galdon-Quiroga J, Rivero-Rodriguez J, Rodriguez-Ramos M, Sanchis-Sanchez L, Dominguez J. First measurements of a scintillator based fast-ion loss detector near the ASDEX Upgrade divertor. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10I106. [PMID: 30399966 DOI: 10.1063/1.5038968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/03/2018] [Indexed: 06/08/2023]
Abstract
A new reciprocating scintillator based fast-ion loss detector has been installed a few centimeters above the outer divertor of the ASDEX Upgrade tokamak and between two of its lower Edge Localized Modes (ELM) mitigation coils. The detector head containing the scintillator screen, Faraday cup, calibration lamp, and collimator systems are installed on a motorized reciprocating system that can adjust its position via remote control in between plasma discharges. Orbit simulations are used to optimize the detector geometry and velocity-space coverage. The scintillator image is transferred to the light acquisition systems outside of the vacuum via a lens relay (embedded in a 3D-printed titanium holder) and an in-vacuum image guide. A charge coupled device camera, for high velocity-space resolution, and an 8 × 8 channel avalanche photo diode camera, for high temporal resolution (up to 2 MHz), are used as light acquisition systems. Initial results showing velocity-space of neutral beam injection prompt losses and fast-ion losses induced by a (2, 1) neoclassical tearing mode are presented.
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Affiliation(s)
- J Gonzalez-Martin
- Department of Mechanical and Manufacturing Engineering, University of Seville, C/Camino de los Descubrimientos s/n, Isla de la Cartuja, Seville, Spain
| | - J Ayllon-Guerola
- Department of Mechanical and Manufacturing Engineering, University of Seville, C/Camino de los Descubrimientos s/n, Isla de la Cartuja, Seville, Spain
| | | | - A Herrmann
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - P Leitenstern
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - P De Marne
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | | | | | | | - J Rivero-Rodriguez
- Department of Mechanical and Manufacturing Engineering, University of Seville, C/Camino de los Descubrimientos s/n, Isla de la Cartuja, Seville, Spain
| | | | | | - J Dominguez
- Department of Mechanical and Manufacturing Engineering, University of Seville, C/Camino de los Descubrimientos s/n, Isla de la Cartuja, Seville, Spain
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Chang JF, Isobe M, Ogawa K, Huang J, Wu CR, Xu Z, Jin Z, Lin SY, Hu LQ. Scintillator-based fast ion loss measurements in the EAST. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E728. [PMID: 27910330 DOI: 10.1063/1.4962245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A new scintillator-based fast ion loss detector (FILD) has been installed on Experimental Advanced Superconducting Tokamak (EAST) to investigate the fast ion loss behavior in high performance plasma with neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). A two dimensional 40 mm × 40 mm scintillator-coated (ZnS:Ag) stainless plate is mounted in the front of the detector, capturing the escaping fast ions. Photons from the scintillator plate are imaged with a Phantom V2010 CCD camera. The lost fast ions can be measured with the pitch angle from 60° to 120° and the gyroradius from 10 mm to 180 mm. This paper will describe the details of FILD diagnostic on EAST and describe preliminary measurements during NBI and ICRH heating.
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Affiliation(s)
- J F Chang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - M Isobe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5259, Japan
| | - K Ogawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5259, Japan
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - C R Wu
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - Z Xu
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - Z Jin
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - S Y Lin
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - L Q Hu
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
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Controlling Fusion Yield in Tokamaks with Spin Polarized Fuel, and Feasibility Studies on the DIII-D Tokamak. JOURNAL OF FUSION ENERGY 2015. [DOI: 10.1007/s10894-015-0015-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pace DC, Pipes R, Fisher RK, Van Zeeland MA. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11D841. [PMID: 25430254 DOI: 10.1063/1.4891596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.
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Affiliation(s)
- D C Pace
- General Atomics, PO Box 85608, San Diego, California 92186-5608, USA
| | - R Pipes
- Department of Physics, University of Hawaii, Hilo, Hawaii 96720-4091, USA
| | - R K Fisher
- General Atomics, PO Box 85608, San Diego, California 92186-5608, USA
| | - M A Van Zeeland
- General Atomics, PO Box 85608, San Diego, California 92186-5608, USA
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Chen X, Heidbrink WW, Van Zeeland MA, Kramer GJ, Pace DC, Petty CC, Austin ME, Fisher RK, Hanson JM, Nazikian R, Zeng L. Using neutral beams as a light ion beam probe (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11E701. [PMID: 25430364 DOI: 10.1063/1.4889733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
By arranging the particle first banana orbits to pass near a distant detector, the light ion beam probe (LIBP) utilizes orbital deflection to probe internal fields and field fluctuations. The LIBP technique takes advantage of (1) the in situ, known source of fast ions created by beam-injected neutral particles that naturally ionize near the plasma edge and (2) various commonly available diagnostics as its detector. These born trapped particles can traverse the plasma core on their inner banana leg before returning to the plasma edge. Orbital displacements (the forces on fast ions) caused by internal instabilities or edge perturbing fields appear as modulated signal at an edge detector. Adjustments in the q-profile and plasma shape that determine the first orbit, as well as the relative position of the source and detector, enable studies under a wide variety of plasma conditions. This diagnostic technique can be used to probe the impact on fast ions of various instabilities, e.g., Alfvén eigenmodes (AEs) and neoclassical tearing modes, and of externally imposed 3D fields, e.g., magnetic perturbations. To date, displacements by AEs and by externally applied resonant magnetic perturbation fields have been measured using a fast ion loss detector. Comparisons with simulations are shown. In addition, nonlinear interactions between fast ions and independent AE waves are revealed by this technique.
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Affiliation(s)
- Xi Chen
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831, USA
| | - W W Heidbrink
- University of California Irvine, Irvine, California 92697, USA
| | - M A Van Zeeland
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - G J Kramer
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543, USA
| | - D C Pace
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - C C Petty
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M E Austin
- University of Texas at Austin, Austin, Texas 78712, USA
| | - R K Fisher
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - J M Hanson
- Columbia University, New York, New York 10027, USA
| | - R Nazikian
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543, USA
| | - L Zeng
- University of California Los Angeles, Los Angeles, California 90095, USA
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Chen X, Austin ME, Fisher RK, Heidbrink WW, Kramer GJ, Nazikian R, Pace DC, Petty CC, Van Zeeland MA. Enhanced localized energetic-ion losses resulting from single-pass interactions with Alfvén eigenmodes. PHYSICAL REVIEW LETTERS 2013; 110:065004. [PMID: 23432263 DOI: 10.1103/physrevlett.110.065004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Indexed: 06/01/2023]
Abstract
We report the first observation of prompt neutral beam-ion losses due to nonresonant scattering induced by toroidal and reversed shear Alfvén eigenmodes in the DIII-D tokamak. The coherent losses are of full energy beam ions expelled from the plasma on their first poloidal orbit. The first-orbit loss mechanism causes enhanced, concentrated losses on the first wall exceeding nominal levels of prompt losses. The loss amplitude scales linearly with the mode amplitude. The data provide a novel and direct measure of the radial excursion or scatter of particles induced by individual modes and may shed light on the mechanism for the scattering of energetic particles in interstellar medium.
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Affiliation(s)
- X Chen
- University of California-Irvine, Irvine, California 92697, USA.
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