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Chavez CT, Egly A, Sepulveda I, Wessel FJ. Measurement of 2D density profiles using a second-harmonic, dispersion interferometer. Rev Sci Instrum 2023; 94:023503. [PMID: 36859024 DOI: 10.1063/5.0119896] [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: 08/10/2022] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
A second-harmonic, dispersion interferometer is used to image large-area (≃5 cm2) plasma-jet and gas-jet density profiles. Achromatic telescopes magnify the diameters of the primary-laser beam (1064 nm) and its second-harmonic (532 nm) before probing the sample and de-magnify the beam diameters after the sample, where the primary beam transfers its phase change to a second, second-harmonic beam, allowing the sample's dispersive-phase change to be measured between two, orthogonally polarized second harmonic beams. The telescopes produce an azimuthally symmetric, dispersive-phase shift in the sample + background phase-change image and in the background phase-change image, which is removed by digital subtraction. The interferometer's performance was verified using standard-optical components as dispersive elements (BK7 lenses and wedge plates), resolving a minimum, phase-change sensitivity of Δϕmin ≳ 15 mrad and spatial resolution of Δxres ≃ 100 μm. The phase change produced by unknown-density objects (a pulsed-plasma-jet and a pulsed-gas-jet) was measured, and their data were used to recover the original, 2D density profiles using an inverse Abel transform: peak-number density, Ngas ≃ 6 × 1020 cm-3 and Ne ≃ 5 × 1016 cm-3; line-integrated density, ∫Ngasdl ∼ 2 × 1019cm-2 and ∫Nedl ∼ 1 × 1016cm-2. The techniques and methods developed here are scalable to even larger probe-beam diameters and frame-capture rates, leading to a diagnostic capability that is well-suited for applications involving the real-time measurement of density.
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Affiliation(s)
- C T Chavez
- L-Egant Solutions, LLC, Irvine, California 92614, USA
| | - A Egly
- L-Egant Solutions, LLC, Irvine, California 92614, USA
| | - I Sepulveda
- L-Egant Solutions, LLC, Irvine, California 92614, USA
| | - F J Wessel
- L-Egant Solutions, LLC, Irvine, California 92614, USA
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Krat S, Prishvitsyn A, Alieva A, Efimov N, Vinitskiy E, Ulasevich D, Izarova A, Podolyako F, Belov A, Meshcheryakov A, Ongena J, Kharchev N, Chernenko A, Khayrutdinov R, Lukash V, Sinelnikov D, Bulgadaryan D, Sorokin I, Gubskiy K, Kaziev A, Kolodko D, Tumarkin V, Isakova A, Grunin A, Begrambekov L, Voskoboinikov R, Melnikov A. MEPhIST-0 Tokamak for Education and Research. Fusion Science and Technology 2023. [DOI: 10.1080/15361055.2022.2149033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- S. Krat
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Prishvitsyn
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Alieva
- National Research Nuclear University MEPhI, Moscow, Russia
| | - N. Efimov
- National Research Nuclear University MEPhI, Moscow, Russia
| | - E. Vinitskiy
- National Research Nuclear University MEPhI, Moscow, Russia
| | - D. Ulasevich
- National Research Nuclear University MEPhI, Moscow, Russia
- National Research Center, Kurchatov Institute, Moscow, Russia
| | - A. Izarova
- National Research Nuclear University MEPhI, Moscow, Russia
| | - F. Podolyako
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Belov
- National Research Nuclear University MEPhI, Moscow, Russia
| | | | - J. Ongena
- Koninklijke Militaire School—Ecole Royale Militaire, Brussels, Belgium
| | - N. Kharchev
- National Research Center, Kurchatov Institute, Moscow, Russia
| | - A. Chernenko
- National Research Nuclear University MEPhI, Moscow, Russia
- National Research Center, Kurchatov Institute, Moscow, Russia
| | - R. Khayrutdinov
- National Research Center, Kurchatov Institute, Moscow, Russia
| | - V. Lukash
- National Research Center, Kurchatov Institute, Moscow, Russia
| | - D. Sinelnikov
- National Research Nuclear University MEPhI, Moscow, Russia
| | - D. Bulgadaryan
- National Research Nuclear University MEPhI, Moscow, Russia
| | - I. Sorokin
- National Research Nuclear University MEPhI, Moscow, Russia
- Russian Academy of Sciences, Kotel’nikov Institute of Radio Engineering and Electronics, Fryazino Branch, Fryazino, Russia
| | - K. Gubskiy
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Kaziev
- National Research Nuclear University MEPhI, Moscow, Russia
| | - D. Kolodko
- National Research Nuclear University MEPhI, Moscow, Russia
- Russian Academy of Sciences, Kotel’nikov Institute of Radio Engineering and Electronics, Fryazino Branch, Fryazino, Russia
| | - V. Tumarkin
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Isakova
- National Research Nuclear University MEPhI, Moscow, Russia
| | - A. Grunin
- National Research Nuclear University MEPhI, Moscow, Russia
| | - L. Begrambekov
- National Research Nuclear University MEPhI, Moscow, Russia
| | - R. Voskoboinikov
- Budker Institute of Nuclear Physics of the Siberian Branch of the RAS, Novosibirsk, Russia
| | - A. Melnikov
- National Research Nuclear University MEPhI, Moscow, Russia
- National Research Center, Kurchatov Institute, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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Wu T, Zhang W, Yin Z. A wide range real-time synchronous demodulation system for the dispersion interferometer on HL-2M. Rev Sci Instrum 2017; 88:093501. [PMID: 28964172 DOI: 10.1063/1.4991318] [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: 06/20/2017] [Accepted: 08/17/2017] [Indexed: 06/07/2023]
Abstract
A real-time synchronous demodulation system has been developed for the dispersion interferometer on a HL-2M tokamak. The system is based on the phase extraction method which uses a ratio of modulation amplitudes. A high-performance field programmable gate array with pipeline process capabilities is used to realize the real time synchronous demodulation algorithm. A fringe jump correction algorithm is applied to follow the fast density changes of the plasma. By using the Peripheral Component Interconnect Express protocol, the electronics can perform real-time density feedback with a temporal resolution of 100 ns. Some experimental results presented show that the electronics can obtain a wide measurement range of 2.28 × 1022 m-2 with high precision.
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Affiliation(s)
- Tongyu Wu
- State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Wei Zhang
- State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Zejie Yin
- State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei 230026, People's Republic of China
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Akiyama T, Van Zeeland MA, Boivin RL, Carlstrom TN, Chavez JA, Muscatello CM, O'Neill RC, Vasquez J, Watkins M, Martin W, Colio A, Finkenthal DK, Brower DL, Chen J, Ding WX, Perry M. Bench testing of a heterodyne CO 2 laser dispersion interferometer for high temporal resolution plasma density measurements. Rev Sci Instrum 2016; 87:123502. [PMID: 28040946 DOI: 10.1063/1.4969055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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
A heterodyne detection scheme is combined with a 10.59 μm CO2 laser dispersion interferometer for the first time to allow large bandwidth measurements in the 10-100 MHz range. The approach employed utilizes a 40 MHz acousto-optic cell operating on the frequency doubled CO2 beam which is obtained using a high 2nd harmonic conversion efficiency orientation patterned gallium arsenide crystal. The measured standard deviation of the line integrated electron density equivalent phase resolution obtained with digital phase demodulation technique, is 4 × 1017 m-2. Air flow was found to significantly affect the baseline of the phase signal, which an optical table cover was able to reduce considerably. The heterodyne dispersion interferometer (DI) approach is found to be robustly insensitive to motion, with measured phase shifts below baseline drifts even in the presence of several centimeters of retroreflector induced path length variations. Plasma induced dispersion was simulated with a wedged ZnSe plate and the measured DI phase shifts are consistent with expectations.
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Affiliation(s)
- T Akiyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan
| | - M A Van Zeeland
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R L Boivin
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - T N Carlstrom
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - J A Chavez
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - C M Muscatello
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R C O'Neill
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - J Vasquez
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M Watkins
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - W Martin
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - A Colio
- Palomar College, San Diego, California 92069, USA
| | | | - D L Brower
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - J Chen
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W X Ding
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - M Perry
- California State University, San Marcos, San Marcos, California 92096, USA
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Zhou Y, Wang HX, Li YG, Li Y, Chen WJ, Yi J, Deng ZC. The conceptual design of interferometer/polarimeter system on HL-2M. Rev Sci Instrum 2016; 87:11E107. [PMID: 27910533 DOI: 10.1063/1.4959911] [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: 06/06/2023]
Abstract
HL-2M is a new medium-sized tokamak with major radius of 1.78 m, minor radius of 0.65 m, and aspect ratio of 2.8 and will be finished soon. In the conceptual design, a double-pass, horizontal view, multi-channel far-infrared (FIR) laser interferometer/polarimeter system (at 432 μm) is proposed to simultaneously measure the phase change and the Faraday rotation for density and current profile reconstruction. A vertical CO2 dispersion interferometer system (with wavelength of 10.6 μm and 5.3 μm) is designed to measure the line density, which will mainly be used for density feedback. The performance of the system is expected to meet the requirement of the measurements on HL-2M, with phase accuracy ∼0.1°, time resolution ∼1 μs, spatial resolution ∼7.2 cm, and density measurement range of 1 × 10 18-1 ×1021 m-3.
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Affiliation(s)
- Y Zhou
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - H X Wang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - Y G Li
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - Y Li
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - W J Chen
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - J Yi
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
| | - Z C Deng
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
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Bamford DJ, Cummings EA, Panasenko D, Fenner DB, Hensley JM, Boivin RL, Carlstrom TN, Van Zeeland MA. CO2 laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements. Rev Sci Instrum 2013; 84:093502. [PMID: 24089824 DOI: 10.1063/1.4819028] [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: 06/02/2023]
Abstract
A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10(17) m(-2) in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.
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Affiliation(s)
- D J Bamford
- Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588, USA
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Bagryansky PA, Anikeev AV, Donin AS, Ivanov AA, Korzhavina MS, Kovalenko Y, Lizunov AA, Lozhkina AN, Maximov VV, Murakhtin SV, Pinzhenin EI, Prikhodko VV, Savkin V, Soldatkina EI, Solomakhin AL, Zaytsev KV. Advances in Confinement Study in the Gas Dynamic Trap Experiment. Fusion Science and Technology 2013. [DOI: 10.13182/fst13-a16919] [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)
- P. A. Bagryansky
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. V. Anikeev
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. S. Donin
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. A. Ivanov
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - M. S. Korzhavina
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - Yu.V. Kovalenko
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. A. Lizunov
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. N. Lozhkina
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - V. V. Maximov
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - S. V. Murakhtin
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - E. I. Pinzhenin
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - V. V. Prikhodko
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - V.Ya. Savkin
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - E. I. Soldatkina
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - A. L. Solomakhin
- Budker Institute of Nuclear Physics, 11 Lavrentyeva prospect, 630090 Novosibirsk, Russia
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
| | - K. V. Zaytsev
- Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk, Russia
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König R, Baldzuhn J, Biedermann C, Burhenn R, Bozhenkov S, Cardella A, Endler M, Hartfuss HJ, Hathiramani D, Hildebrandt D, Hirsch M, Jakubowski M, Kocsis G, Kornejev P, Krychowiak M, Laqua HP, Laux M, Oosterbeek JW, Pasch E, Richert T, Schneider W, Sunn-Pedersen T, Thomsen H, Weller A, Werner A, Wolf R, Zhang D, Zoletnik S. Diagnostics development for quasi-steady-state operation of the Wendelstein 7-X stellarator (invited). Rev Sci Instrum 2012; 83:10D730. [PMID: 23126902 DOI: 10.1063/1.4733531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The critical issues in the development of diagnostics, which need to work robust and reliable under quasi-steady state conditions for the discharge durations of 30 min and which cannot be maintained throughout the one week duration of each operation phase of the Wendelstein 7-X stellarator, are being discussed.
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Affiliation(s)
- R König
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Greifswald, Germany.
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Affiliation(s)
- A. Krämer-Flecken
- Institut für Energie und Klimaforschung / Plasmaphysik, Forschungszentrum Jülich Association EURATOM-FZJ, Trilateral Euregio Cluster, D-52425, Jülich, Germany
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