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Kostic A, Crombé K, Dux R, Griener M, Ochoukov R, Shesterikov I, Suárez López G, Usoltceva M, Casagrande R, Martin EH, Noterdaeme JM. Polarization Stark spectroscopy for spatially resolved measurements of electric fields in the sheaths of ICRF antenna. Rev Sci Instrum 2019; 90:123101. [PMID: 31893862 DOI: 10.1063/1.5123659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
A multichannel spectroscopic diagnostic based on the Stark effect on helium lines was developed and implemented in IShTAR (Ion Cyclotron Sheath Test ARrangement) to measure the spatial distribution of electric fields across the radio frequency sheaths of the ion cyclotron antenna. Direct measurements of the DC electric fields in the antenna sheaths are an important missing component in understanding the antenna-plasma edge interactions in magnetically confined fusion plasmas since they will be used to benchmark theoretical models against real antenna operation. Along with the high-resolution Czerny-Turner monochromator and a detector with an intensifier, the hardware relies on the 2 chained set of linear-to-linear fiber bundles that provide seven optical channels capable of resolving an 8.4 mm region in the vicinity of the antenna's box. The diagnostic is supported with local helium gas puff, enabling it to operate in nonhelium plasmas. Spatially resolved electric field was measured for two discharge configurations, one with and one without the ICRF antenna. The results show a clear difference in the shape of the DC electric field's spatial profile for the two cases studied, with the elevated values when the ICRF antenna was operating. This demonstrates the ability of the diagnostic to measure even small relative changes in the intensity of the electric field.
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Affiliation(s)
- A Kostic
- Department of Applied Physics, Ghent University, 9000 Ghent, Belgium
| | - K Crombé
- Department of Applied Physics, Ghent University, 9000 Ghent, Belgium
| | - R Dux
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - M Griener
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - R Ochoukov
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - I Shesterikov
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - G Suárez López
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - M Usoltceva
- Department of Applied Physics, Ghent University, 9000 Ghent, Belgium
| | - R Casagrande
- Department of Applied Physics, Ghent University, 9000 Ghent, Belgium
| | - E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - J-M Noterdaeme
- Department of Applied Physics, Ghent University, 9000 Ghent, Belgium
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Kostic A, Dux R, Crombé K, Nikiforov A, Ochoukov R, Shesterikov I, Martin EH, Noterdaeme JM. Development of a spectroscopic diagnostic tool for electric field measurements in IShTAR (Ion cyclotron Sheath Test ARrangement). Rev Sci Instrum 2018; 89:10D115. [PMID: 30399884 DOI: 10.1063/1.5039321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/08/2018] [Indexed: 06/08/2023]
Abstract
IShTAR, Ion cyclotron Sheath Test ARrangement, is a linear device dedicated to the investigation of the edge plasma-ICRF (Ion Cyclotron Range of Frequencies) antenna interactions in tokamak edge-like conditions and serves as a platform for a diagnostic development for measuring the electric fields in the vicinity of ICRF antennas. We present here our progress in the development of an optical emission spectroscopy method for measuring the electric fields which concentrates on the changes in the helium spectral line profiles introduced by the external electrical field, i.e., the Stark effect. To be able to fully control the operating parameters, at the first stage of the study, the measurements are conducted on a planar electrode installed in the centre of the plasma column in IShTAR's helicon plasma source. At the second stage, the measurements are performed in the vicinity of IShTAR's ICRF antenna.
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Affiliation(s)
- A Kostic
- Department of Applied Physics, Ghent University, Ghent, Belgium
| | - R Dux
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - K Crombé
- Department of Applied Physics, Ghent University, Ghent, Belgium
| | - A Nikiforov
- Department of Applied Physics, Ghent University, Ghent, Belgium
| | - R Ochoukov
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - I Shesterikov
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - J-M Noterdaeme
- Department of Applied Physics, Ghent University, Ghent, Belgium
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Martin EH, Lau C, Brookman MW, Lohr J. A spectroscopic electric field vector imaging diagnostic for electron cyclotron heating systems. Rev Sci Instrum 2018; 89:10D117. [PMID: 30399893 DOI: 10.1063/1.5038670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
An experimental measurement of the wave electric field vector provides important data that can be used to directly compare against 3D full-wave simulations. This direct comparison yields the fastest approach toward identifying missing physics in computational models and providing a high fidelity validation platform. In this paper, we present a diagnostic that is capable of imaging the Electron Cyclotron (EC) wave electric field vector by acquiring filtered images of polarized D β spectral satellites. The diagnostic is designed to have a spatial and temporal resolution on the order of 100 μm and 100 μs, respectively. The diagnostic purpose is to provide experimental data for the direct validation of full-wave codes used to predict EC beam propagation and absorption and to provide real-time monitoring of EC waves.
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Affiliation(s)
- E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - M W Brookman
- General Atomics, 3550 General Atomics Ct., San Diego, California 92121, USA
| | - J Lohr
- General Atomics, 3550 General Atomics Ct., San Diego, California 92121, USA
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Goulding RH, Caughman JBO, Rapp J, Biewer TM, Bigelow TS, Campbell IH, Caneses JF, Donovan D, Kafle N, Martin EH, Ray HB, Shaw GC, Showers MA. Progress in the Development of a High Power Helicon Plasma Source for the Materials Plasma Exposure Experiment. Fusion Science and Technology 2017. [DOI: 10.1080/15361055.2017.1352429] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- R. H. Goulding
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | | | - J. Rapp
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - T. M. Biewer
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - T. S. Bigelow
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - I. H. Campbell
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - J. F. Caneses
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - D. Donovan
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - N. Kafle
- University of Tennessee, Bredesen Center, Knoxville, Tennessee 37996
| | - E. H. Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - H. B. Ray
- University of Tennessee, Bredesen Center, Knoxville, Tennessee 37996
| | - G. C. Shaw
- University of Tennessee, Bredesen Center, Knoxville, Tennessee 37996
| | - M. A. Showers
- University of Tennessee, Bredesen Center, Knoxville, Tennessee 37996
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Klepper CC, Caughman JP, Martin EH, Kreter A, Schweer B, Unterberg B. Feasibility of an In-Vacuo Implementation of Glow-Discharge Optical Spectroscopy and Status of Its Development for the PSI-2 Facility. Fusion Science and Technology 2017. [DOI: 10.13182/fst13-a16903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- C. C. Klepper
- Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169, USA
| | - J. P. Caughman
- Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169, USA
| | - E. H. Martin
- Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169, USA
| | - A. Kreter
- Institute for Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOMFZJ, Trilateral Euregio Cluster, Jülich, Germany
| | - B. Schweer
- Institute for Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOMFZJ, Trilateral Euregio Cluster, Jülich, Germany
| | - B. Unterberg
- Institute for Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOMFZJ, Trilateral Euregio Cluster, Jülich, Germany
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Martin EH, Zafar A, Caughman JBO, Isler RC, Bell GL. Applications of Doppler-free saturation spectroscopy for edge physics studies (invited). Rev Sci Instrum 2016; 87:11E402. [PMID: 27910367 DOI: 10.1063/1.4961287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of the atom through measurement of the spectral line profile. This is achieved through a significant decrease in the Doppler broadening and essentially an elimination of the instrument broadening inherent to passive spectroscopic techniques. In this paper we present the technique and associated physics of Doppler-free saturation spectroscopy in addition to how one selects the appropriate transition. Simulations of Hδ spectra are presented to illustrate the increased sensitivity to both electric field and electron density measurements.
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Affiliation(s)
- E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Zafar
- Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - J B O Caughman
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R C Isler
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G L Bell
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Zafar A, Martin EH, Shannon SC, Isler RC, Caughman JBO. A temporally and spatially resolved electron density diagnostic method for the edge plasma based on Stark broadening. Rev Sci Instrum 2016; 87:11E505. [PMID: 27910427 DOI: 10.1063/1.4955484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An electron density diagnostic (≥1010 cm-3) capable of high temporal (ms) and spatial (mm) resolution is currently under development at Oak Ridge National Laboratory. The diagnostic is based on measuring the Stark broadened, Doppler-free spectral line profile of the n = 6-2 hydrogen Balmer series transition. The profile is then fit to a fully quantum mechanical model including the appropriate electric and magnetic field operators. The quasi-static approach used to calculate the Doppler-free spectral line profile is outlined here and the results from the model are presented for H-δ spectra for electron densities of 1010-1013 cm-3. The profile shows complex behavior due to the interaction between the magnetic substates of the atom.
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Affiliation(s)
- A Zafar
- Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - S C Shannon
- Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - R C Isler
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - J B O Caughman
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
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Liang J, Crowther TW, Picard N, Wiser S, Zhou M, Alberti G, Schulze ED, McGuire AD, Bozzato F, Pretzsch H, de-Miguel S, Paquette A, Herault B, Scherer-Lorenzen M, Barrett CB, Glick HB, Hengeveld GM, Nabuurs GJ, Pfautsch S, Viana H, Vibrans AC, Ammer C, Schall P, Verbyla D, Tchebakova N, Fischer M, Watson JV, Chen HYH, Lei X, Schelhaas MJ, Lu H, Gianelle D, Parfenova EI, Salas C, Lee E, Lee B, Kim HS, Bruelheide H, Coomes DA, Piotto D, Sunderland T, Schmid B, Gourlet-Fleury S, Sonke B, Tavani R, Zhu J, Brandl S, Vayreda J, Kitahara F, Searle EB, Neldner VJ, Ngugi MR, Baraloto C, Frizzera L, Ba azy R, Oleksyn J, Zawi a-Nied wiecki T, Bouriaud O, Bussotti F, Finer L, Jaroszewicz B, Jucker T, Valladares F, Jagodzinski AM, Peri PL, Gonmadje C, Marthy W, OBrien T, Martin EH, Marshall AR, Rovero F, Bitariho R, Niklaus PA, Alvarez-Loayza P, Chamuya N, Valencia R, Mortier F, Wortel V, Engone-Obiang NL, Ferreira LV, Odeke DE, Vasquez RM, Lewis SL, Reich PB. Positive biodiversity-productivity relationship predominant in global forests. Science 2016; 354:354/6309/aaf8957. [DOI: 10.1126/science.aaf8957] [Citation(s) in RCA: 659] [Impact Index Per Article: 82.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/22/2016] [Indexed: 11/02/2022]
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Klepper CC, Martin EH, Isler RC, Colas L, Goniche M, Hillairet J, Panayotis S, Pegourié B, Jacquot J, Lotte P, Colledani G, Biewer TM, Caughman JB, Ekedahl A, Green DL, Harris JH, Hillis DL, Shannon SC, Litaudon X. Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited). Rev Sci Instrum 2014; 85:11E301. [PMID: 25430306 DOI: 10.1063/1.4890247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.
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Affiliation(s)
- C C Klepper
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - R C Isler
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - L Colas
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - M Goniche
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - J Hillairet
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - S Panayotis
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - B Pegourié
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - J Jacquot
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - Ph Lotte
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - G Colledani
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - T M Biewer
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - J B Caughman
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - A Ekedahl
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
| | - D L Green
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - J H Harris
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - D L Hillis
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA
| | - S C Shannon
- North Carolina State University, Raleigh, North Carolina 27607, USA
| | - X Litaudon
- CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
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Klepper CC, Isler RC, Hillairet J, Martin EH, Colas L, Ekedahl A, Goniche M, Harris JH, Hillis DL, Panayotis S, Pegourié B, Lotte P, Colledani G, Martin V. Dynamic Stark spectroscopic measurements of microwave electric fields inside the plasma near a high-power antenna. Phys Rev Lett 2013; 110:215005. [PMID: 23901403 DOI: 10.1103/physrevlett.110.215005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fully dynamic Stark effect visible spectroscopy was used for the first time to directly measure the local rf electric field in the boundary plasma near a high-power antenna in high-performance, magnetically confined, fusion energy experiment. The measurement was performed in the superconducting tokamak Tore Supra, in the near field of a 1–3 MW, lower-hybrid, 3.7 GHz wave-launch antenna, and combined with modeling of neutral atom transport to estimate the local rf electric field amplitude (as low as 1–2 kV/cm) and direction in this region. The measurement was then shown to be consistent with the predicted values from a 2D full-wave propagation model. Notably the measurement confirmed that the electric field direction deviates substantially from the direction in which it is launched by the waveguides as it penetrates only a few cm radially inward into the plasma from the waveguides, consistent with the model.
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Affiliation(s)
- C C Klepper
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
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Hevia AC, Fernandez MM, Palacio JMA, Martin EH, Castro MG, Reguero JJR. ECG as a part of the preparticipation screening programme: an old and still present international dilemma. Br J Sports Med 2009; 45:776-9. [DOI: 10.1136/bjsm.2009.063958] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Martin EH. The Medical Letter Bag. Tex Med J (Austin) 1919; 34:311. [PMID: 36957716 PMCID: PMC9651398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
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Martin EH. THE TREATMENT OF SYPHILIS WITH ARSENICAL PREPARATIONS. South Med J 1917. [DOI: 10.1097/00007611-191703000-00005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Martin EH. Concerning Dr. Howell's Case. Atlanta Med Surg J (1884) 1891; 7:712-714. [PMID: 35828620 PMCID: PMC8937260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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