1
|
Lizunov A, Berbasova T, Khilchenko A, Kvashnin A, Puryga E, Sandomirsky A, Zubarev P. High resolution Thomson scattering diagnostic for measurements of radial profiles of electron temperature and density in the gas dynamic trap. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:033509. [PMID: 37012786 DOI: 10.1063/5.0123329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/22/2023] [Indexed: 06/19/2023]
Abstract
The incoherent Thomson scattering diagnostic with multiple lines of sight is installed at the gas dynamic trap (GDT) for measurements of radial profiles of the plasma electron temperature and density. The diagnostic is built on the Nd:YAG laser operating at 1064 nm. The laser input beamline is provided with an automatic system for alignment status monitoring and correction. The collecting lens uses ∼90° scattering geometry having 11 lines of sight in total. Presently, six of them (covering the full plasma radius from the axis to the limiter) are equipped with high etendue (f/2.4) interference filter spectrometers. The design of the spectrometer's data acquisition system based on the "time stretch" principle allowed for the 12 bits vertical resolution with a sampling rate of 5 GSample/s and a maximum sustainable measurement repetition frequency of 40 kHz. The repetition frequency is the crucial parameter for the study of plasma dynamics with a new pulse burst laser to be started in early 2023. Results of the diagnostic operation in several GDT campaigns show that radial profiles are routinely delivered with the typical observation error of 2%-3% for Te ⩾ 20 eV in a single pulse. After Raman scattering calibration, the diagnostic is capable to measure the electron density profile with the resolution ne (min)≃4⋅1018m-3 and error bars of 5%.
Collapse
Affiliation(s)
- A Lizunov
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| | - T Berbasova
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| | - A Khilchenko
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| | - A Kvashnin
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| | - E Puryga
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| | - A Sandomirsky
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - P Zubarev
- Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia
| |
Collapse
|
2
|
Chavez CT, Egly A, Sepulveda I, Wessel FJ. Measurement of 2D density profiles using a second-harmonic, dispersion interferometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:023503. [PMID: 36859024 DOI: 10.1063/5.0119896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
3
|
Li WM, Liu HQ, Zeng L, Wang SX, Lian H, Yang Y, Wei XC, Zhang Y, Li MG. Bench test of phase measurement on dispersion interferometer for EAST. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:026105. [PMID: 30831737 DOI: 10.1063/1.5058705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
In recent years, different traditional interferometers have been the necessary diagnostic of electronic density measurement on fusion devices. Until now, two main problems always influence the density measurement: the mechanical vibration and fringe jump in the calculation. The dispersion interferometer (DI) with a long-wavelength infrared wavelength is a good choice because mechanical vibrations can be canceled and the fringe jump can be inhibited. This paper describes the bench test of phase measurement using a wedge instead of plasma on the DI. The results show good agreement with the theoretical calculations. In the background measurement, this DI without a vibration isolation system has good performance, and the drift of the baseline is less than 2 × 1017 m-2 in 3 s and less than 5 × 1017 m-2 in 400 s. Plasma data will be obtained during the next campaign on EAST (Experimental and Advanced Superconducting Tokamak).
Collapse
Affiliation(s)
- W M Li
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - H Q Liu
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - L Zeng
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - S X Wang
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - H Lian
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Y Yang
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - X C Wei
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Y Zhang
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - M G Li
- Institute of Plasma Physics Chinese Academy of Sciences, Hefei, Anhui 230031, China
| |
Collapse
|
4
|
Akiyama T, Sirinelli A, Watts C, Shigin P, Vayakis G, Walsh M. Design of a dispersion interferometer combined with a polarimeter to increase the electron density measurement reliability on ITER. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E133. [PMID: 27910496 DOI: 10.1063/1.4962050] [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 dispersion interferometer is a reliable density measurement system and is being designed as a complementary density diagnostic on ITER. The dispersion interferometer is inherently insensitive to mechanical vibrations, and a combined polarimeter with the same line of sight can correct fringe jump errors. A proof of the principle of the CO2 laser dispersion interferometer combined with the PEM polarimeter was recently conducted, where the phase shift and the polarization angle were successfully measured simultaneously. Standard deviations of the line-average density and the polarization angle measurements over 1 s are 9 × 1016 m-2 and 0.19°, respectively, with a time constant of 100 μs. Drifts of the zero point, which determine the resolution in steady-state operation, correspond to 0.25% and 1% of the phase shift and the Faraday rotation angle expected on ITER.
Collapse
Affiliation(s)
- T Akiyama
- National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan
| | - A Sirinelli
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance, France
| | - C Watts
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance, France
| | - P Shigin
- NRNU MEPhI, 31 Kashirskoe sh., Moscow 115409, Russian Federation
| | - G Vayakis
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance, France
| | - M Walsh
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance, France
| |
Collapse
|
5
|
Akiyama T, Yasuhara R, Kawahata K, Okajima S, Nakayama K. Dispersion interferometer using modulation amplitudes on LHD (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11D301. [PMID: 25430161 DOI: 10.1063/1.4886777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Since a dispersion interferometer is insensitive to mechanical vibrations, a vibration compensation system is not necessary. The CO2 laser dispersion interferometer with phase modulations on the Large Helical Device utilizes the new phase extraction method which uses modulation amplitudes and can improve a disadvantage of the original dispersion interferometer: measurement errors caused by variations of detected intensities. The phase variation within ±2 × 10(17) m(-3) is obtained without vibration compensation system. The measured line averaged electron density with the dispersion interferometer shows good agreement with that with the existing far infrared laser interferometer. Fringe jump errors in high density ranging up to 1.5 × 10(20) m(-3) can be overcome by a sufficient sampling rate of about 100 kHz.
Collapse
Affiliation(s)
- T Akiyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan
| | - R Yasuhara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan
| | - K Kawahata
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan
| | - S Okajima
- Chubu University, Matsumoto-cho, Kasugai-shi, Aichi 487-8501, Japan
| | - K Nakayama
- Chubu University, Matsumoto-cho, Kasugai-shi, Aichi 487-8501, Japan
| |
Collapse
|
6
|
Arakawa H, Tojo H, Sasao H, Kawano Y, Itami K. A new method for determining the plasma electron density using optical frequency comb interferometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:043508. [PMID: 24784608 DOI: 10.1063/1.4870925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new method of plasma electron density measurement using interferometric phases (fractional fringes) of an optical frequency comb interferometer is proposed. Using the characteristics of the optical frequency comb laser, high density measurement can be achieved without fringe counting errors. Simulations show that the short wavelength and wide wavelength range of the laser source and low noise in interferometric phases measurements are effective to reduce ambiguity of measured density.
Collapse
Affiliation(s)
- Hiroyuki Arakawa
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan
| | - Hiroshi Tojo
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan
| | - Hajime Sasao
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan
| | - Yasunori Kawano
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan
| | - Kiyoshi Itami
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan
| |
Collapse
|
7
|
Arakawa H, Kawano Y, Itami K. A new method for determining the plasma electron density using three-color interferometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:063507. [PMID: 22755627 DOI: 10.1063/1.4731651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A new method for determining the plasma electron density using the fractional fringes on three-color interferometer is proposed. Integrated phase shift on each interferometer is derived without using the temporal history of the fractional fringes. The dependence on the fringe resolution and the electrical noise are simulated on the wavelengths of CO(2) laser. Short-time integrations of the fractional fringes enhance the reliability of this method.
Collapse
Affiliation(s)
- Hiroyuki Arakawa
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193, Japan.
| | | | | |
Collapse
|
8
|
Dreier H, Bagryansky P, Baumgarten N, Biel W, Lambertz HT, Lehnen M, Lizunov A, Solomakhin A. First results from the modular multi-channel dispersion interferometer at the TEXTOR tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:063509. [PMID: 21721693 DOI: 10.1063/1.3600896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
At the TEXTOR tokamak in Jülich, Germany, a modular dispersion interferometer was installed and operated for the first time. Equipped with four lines of sight, the line-integrated density could be measured in parallel at different major radii with a resolution of better than 3 × 10(17) m(-2). This paper will describe the setup and show the first measurement results. Among others, it was possible to detect the evolution of a disruption with a time resolution of 4 μs. The movement of the runaway beam following the disruption could be resolved spatially and temporarily.
Collapse
Affiliation(s)
- H Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Wendelsteinstr. 1, D-17491 Greifswald, Germany
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Solomakhin AL, Bagryansky PA, Biel W, Dreier H, Ivanenko SV, Khilchenko AD, Kovalenko YV, Kvashnin AN, Lambertz HT, Lizunov AA, Lvovskiy AV, Savkin VY. Measurement of Plasma Density in Modern Fusion Devices by Dispersion Interferometer. FUSION SCIENCE AND TECHNOLOGY 2011. [DOI: 10.13182/fst11-a11588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. L. Solomakhin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - P. A. Bagryansky
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - W. Biel
- Forschungszentrum Jülich GmbH, Association EURATOM-FZ Jülich, Institut für Plasmaphysik, Trilateral Euregio Cluster, 52425 Jülich, Germany
| | - H. Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Wendelsteinstr. 1, D-17491 Greifswald, Germany
| | - S. V. Ivanenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - A. D. Khilchenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - Yu. V. Kovalenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - A. N. Kvashnin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - H. T. Lambertz
- Forschungszentrum Jülich GmbH, Association EURATOM-FZ Jülich, Institut für Plasmaphysik, Trilateral Euregio Cluster, 52425 Jülich, Germany
| | - A. A. Lizunov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - A. V. Lvovskiy
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - V. Ya. Savkin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| |
Collapse
|
10
|
Burmasov VS, Bobylev VB, Ivanova AA, Ivanenko SV, Kasatov AA, Kasatov DA, Kuklin KN, Popov SS, Puryga EA, Rovenskikh AF, Sklyarov VF. CO 2 Interferometer for GOL-3 Multimirror Trap. FUSION SCIENCE AND TECHNOLOGY 2011. [DOI: 10.13182/fst11-a11642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- V. S. Burmasov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - V. B. Bobylev
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - A. A. Ivanova
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk Technical State University, 630092, Novosibirsk, Russia
| | - S. V. Ivanenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - A. A. Kasatov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - D. A. Kasatov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - K. N. Kuklin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - S. S. Popov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - E. A. Puryga
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk Technical State University, 630092, Novosibirsk, Russia
| | - A. F. Rovenskikh
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - V. F. Sklyarov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk Technical State University, 630092, Novosibirsk, Russia
| |
Collapse
|
11
|
Akiyama T, Kawahata K, Okajima S, Nakayama K. Development of CO2 laser dispersion interferometer with photoelastic modulator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10D501. [PMID: 21033856 DOI: 10.1063/1.3460453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A dispersion interferometer is one of the promising methods of the electron density measurement on large and high density fusion devices. This paper describes development of a CO(2) laser dispersion interferometer with a photoelastic modulator for phase modulation. In order to make the dispersion interferometer free from variations of the detected intensity, a new phase extraction method is introduced: The phase shift is evaluated from a ratio of amplitudes of the fundamental and the second harmonics of the phase modulation frequency in the detected interference signal. The proof-of-principle experiments demonstrate the feasibility of this method.
Collapse
Affiliation(s)
- T Akiyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan.
| | | | | | | |
Collapse
|