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He Z, Kafle N, Gebhart TE, Biewer TM, Zhang Z. Implementation of a portable diagnostic system for Thomson scattering measurements on an electrothermal arc source. Rev Sci Instrum 2022; 93:113526. [PMID: 36461429 DOI: 10.1063/5.0101835] [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: 06/03/2022] [Accepted: 10/04/2022] [Indexed: 06/17/2023]
Abstract
To fulfill the increasing needs of diagnostic support for researchers in plasma technology, a portable diagnostic package (PDP) equipped for both laser Thomson scattering (TS) and optical emission spectroscopy has been designed and constructed at Oak Ridge National Laboratory (ORNL), aiming to measure the temperature and number density of electrons and temperatures of ions in plasma devices. The PDP has been initially implemented on a high density and low temperature electrothermal arc source (ET-arc) at ORNL to test its TS capability. TS from the plasmas in the ET-arc has been obtained using the PDP. The electron temperature and number density were determined from TS spectra. These results were then compared to measurements from previous studies on the ET-arc. The TS diagnostic measured 0.8 ± 0.1, 1.3 ± 0.2, and 0.7 ± 0.1 eV and (4.4 ± 0.5) × 1021, (5.9 ± 0.7) × 1021, and (4.3 ± 0.5) x 1021 m-3, respectively, from three lines of sight that transect the plasma column.
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Affiliation(s)
- Z He
- University of Tennessee-Knoxville, Knoxville, Tennessee 37996, USA
| | - N Kafle
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T E Gebhart
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T M Biewer
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Zhang
- University of Tennessee-Knoxville, Knoxville, Tennessee 37996, USA
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Baylor LR, Meitner SJ, Gebhart TE, Lang PT, Ploeckl B. Issues in Formation of Cryogenic Pellets for Fusion Applications. Fusion Science and Technology 2021. [DOI: 10.1080/15361055.2021.1887715] [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: 10/21/2022]
Affiliation(s)
- L. R. Baylor
- Oak Ridge National Laboratory, Fusion Energy Division, P.O. Box 2008, Oak Ridge, Tennessee 37831-6169
| | - S. J. Meitner
- Oak Ridge National Laboratory, Fusion Energy Division, P.O. Box 2008, Oak Ridge, Tennessee 37831-6169
| | - T. E. Gebhart
- Oak Ridge National Laboratory, Fusion Energy Division, P.O. Box 2008, Oak Ridge, Tennessee 37831-6169
| | - P. T. Lang
- Max Planck Institute of Plasma Physics, Garching, Germany
| | - B. Ploeckl
- Max Planck Institute of Plasma Physics, Garching, Germany
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3
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Gebhart TE, Ghiozzi AG, Velez DA, Baylor LR, Chilen C, Meitner SJ. Shear Strength and Release of Large Cryogenic Pellets from the Barrel of a Shattered Pellet Injector for Disruption Mitigation. Fusion Science and Technology 2021. [DOI: 10.1080/15361055.2021.1874766] [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: 10/21/2022]
Affiliation(s)
- T. E. Gebhart
- Oak Ridge National Laboratory, Fusion Energy Division, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
| | - A. G. Ghiozzi
- Oak Ridge National Laboratory, ORISE, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
| | - D. A. Velez
- Oak Ridge National Laboratory, ORISE, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
| | - L. R. Baylor
- Oak Ridge National Laboratory, Fusion Energy Division, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
| | - C. Chilen
- Oak Ridge National Laboratory, ORISE, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
| | - S. J. Meitner
- Oak Ridge National Laboratory, Fusion Energy Division, 1 Bethel Valley Road, Oak Ridge, Tennessee, 37830
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Ghiozzi AG, Velez DA, Gebhart TE, Gehrig ML, Ericson MN, Baylor LR, Rasmussen DA. Pressure Response Optimization of an Eddy Current-Driven Flyer Plate Valve for the ITER Shattered Pellet Injection System. Fusion Science and Technology 2021. [DOI: 10.1080/15361055.2021.1906149] [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: 10/20/2022]
Affiliation(s)
- A. G. Ghiozzi
- Oak Ridge National Laboratory, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830
| | - D. A. Velez
- Oak Ridge National Laboratory, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830
| | - T. E. Gebhart
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
| | - M. L. Gehrig
- Missouri University of Science and Technology, Department of Nuclear Engineering and Radiation Sciences, Rolla, Missouri
| | - M. N. Ericson
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
| | - L. R. Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
| | - D. A. Rasmussen
- Oak Ridge National Laboratory, US ITER, Oak Ridge, Tennessee 37830
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Lindquist EG, Gebhart TE, Elliott D, Garren EW, He Z, Kafle N, Smith CD, Thomas CE, Zinkle SJ, Biewer TM. Reconfiguration of an Electrothermal-Arc Plasma Source for In Situ PMI Studies. Fusion Science and Technology 2021. [DOI: 10.1080/15361055.2021.1909989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- E. G. Lindquist
- University of Tennessee, Nuclear Engineering Department, Knoxville, Tennessee
| | - T. E. Gebhart
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - D. Elliott
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - E. W. Garren
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - Z. He
- University of Tennessee, Mechanical Aerospace and Biological Engineering Department, Knoxville, Tennessee
| | - N. Kafle
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - C. D. Smith
- University of Tennessee, Mechanical Aerospace and Biological Engineering Department, Knoxville, Tennessee
| | - C. E. Thomas
- Third Dimension Technologies LLC, Oak Ridge, Tennessee
| | - S. J. Zinkle
- University of Tennessee, Nuclear Engineering Department, Knoxville, Tennessee
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - T. M. Biewer
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
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Kafle N, Elliott D, Garren EW, He Z, Gebhart TE, Zhang Z, Biewer TM. Design and implementation of a portable diagnostic system for Thomson scattering and optical emission spectroscopy measurements. Rev Sci Instrum 2021; 92:063002. [PMID: 34243554 DOI: 10.1063/5.0043818] [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: 01/11/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
A diagnostic system, which has a design goal of high-portability, has been designed at Oak Ridge National Laboratory (ORNL). This project aims at providing measurements of key plasma parameters (ne, Te, ni, Ti) for fusion-relevant devices, utilizing Thomson scattering (TS) and optical emission spectroscopy (OES). The innovative design employs mostly commercial off-the-shelf instrumentation and a traveling team of researchers to conduct measurements at various magnetic-confinement plasma devices. The TS diagnostic uses a Quantel Q-smart 1500 Nd:YAG laser with a 2ω harmonic generator to produce up to 850 mJ of 532 nm laser pulses at 10 Hz. Collection optics placed at the detection port consists of an 11 × 3 optical fiber bundle, where the TS diagnostic uses an 11 × 1 subset array of the fibers, the OES diagnostic uses another 11 fibers, and the remaining fibers are available to the host institution. The detection system is comprised of two separate IsoPlane-320 spectrometers with triple-grating turrets of various line spacing and two PI-MAX 4 intensified CCD detectors, used simultaneously to measure a broad range of ion, impurity, and electron parameters. The self-contained diagnostic package also includes a data processing and storage system. The design and initial implementation of the TS-OES diagnostic system are described. The experiments from the proof-of-principle operation of the portable package on a high density (∼2.5 × 1022 m-3) and low-temperature (∼5 eV) electrothermal arc source at ORNL are also discussed.
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Affiliation(s)
- N Kafle
- Oak Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D Elliott
- Oak Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E W Garren
- Oak Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z He
- University of Tennessee-Knoxville, Knoxville, Tennessee 37996, USA
| | - T E Gebhart
- Oak Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Zhang
- University of Tennessee-Knoxville, Knoxville, Tennessee 37996, USA
| | - T M Biewer
- Oak Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Smith CD, Biewer TM, Gebhart TE, Lindquist EG, Thomas CE. Measurements of dynamic surface changes by digital holography for in situ plasma erosion applications. Rev Sci Instrum 2021; 92:033504. [PMID: 33820073 DOI: 10.1063/5.0040566] [Citation(s) in RCA: 1] [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] [Received: 12/14/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
There are currently few viable diagnostic techniques for in situ measurement of plasma facing component erosion. Digital holography is intended to fill this gap. Progress on the development of single and dual CO2 laser digital holography diagnostics for in situ plasma facing component erosion is discussed. The dual laser mode's synthetic wavelength allows the measurable range to be expanded by a factor of ∼400 compared to single laser digital holography. This allows the diagnostic to measure surface height changes of up to 4.5 μm in single laser mode and up to 2 mm in dual laser mode. Results include ex situ measurements of plasma eroded targets and also dynamic measurements of nm and μm scale motion of a target mounted on a precision translation stage. Dynamic measurements have successfully been made with the system operating in both single and dual laser modes, from ∼50 nm to ∼4 μm in single laser mode and up to ∼400 μm in dual laser mode (limited only by the stage speed and camera acquisition duration). These results demonstrate the feasibility of using digital holography to characterize plasma facing component erosion dynamically, i.e., during plasma exposure. Results of proof-of-principle in situ digital holographic measurements of targets exposed to an electrothermal arc plasma source are presented.
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Affiliation(s)
- C D Smith
- Mechanical, Aerospace & Biomedical Engineering Department, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - T M Biewer
- Fusion Energy Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T E Gebhart
- Fusion Energy Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E G Lindquist
- Nuclear Engineering Department, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C E Thomas
- Third Dimension Technologies, Oak Ridge, Tennessee 37830, USA
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Gebhart TE, Baylor LR, Meitner SJ. Analysis of the Shattered Pellet Injection Fragment Plumes Generated by Machine Specific Shatter Tube Designs. Fusion Science and Technology 2021. [DOI: 10.1080/15361055.2020.1842682] [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: 10/22/2022]
Affiliation(s)
- T. E. Gebhart
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - L. R. Baylor
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
| | - S. J. Meitner
- Oak Ridge National Laboratory, Fusion Energy Division, Oak Ridge, Tennessee
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Gebhart TE, Baylor LR, Meitner SJ. Shatter Thresholds and Fragment Size Distributions of Deuterium–Neon Mixture Cryogenic Pellets for Tokamak Thermal Mitigation. Fusion Science and Technology 2020. [DOI: 10.1080/15361055.2020.1812991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | - L. R. Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
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Coburn JD, Gebhart TE, Parish CM, Unterberg E, Canik J, Barsoum MW, Bourham M. Surface Erosion of Plasma-Facing Materials Using an Electrothermal Plasma Source and Ion Beam Micro-Trenches. Fusion Science and Technology 2019. [DOI: 10.1080/15361055.2019.1623570] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- J. D. Coburn
- North Carolina State University, Raleigh, North Carolina
| | | | - C. M. Parish
- Oak Ridge National Laboratory, Oak Ridge, Tennesee
| | - E. Unterberg
- Oak Ridge National Laboratory, Oak Ridge, Tennesee
| | - J. Canik
- Oak Ridge National Laboratory, Oak Ridge, Tennesee
| | | | - M. Bourham
- North Carolina State University, Raleigh, North Carolina
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Gebhart TE, Meitner SJ, Baylor LR. Development of Solenoid-Driven and Pneumatic Punches for Launching High-Z Cryogenic Pellets for Tokamak Disruption Mitigation Experiments. Fusion Science and Technology 2019. [DOI: 10.1080/15361055.2019.1592997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- T. E. Gebhart
- Oak Ridge National Laboratory, P.O. BOX 2008, Building 5600, MS 6169, Oak Ridge, Tennessee 37831
| | - S. J. Meitner
- Oak Ridge National Laboratory, P.O. BOX 2008, Building 5600, MS 6169, Oak Ridge, Tennessee 37831
| | - L. R. Baylor
- Oak Ridge National Laboratory, P.O. BOX 2008, Building 5600, MS 6169, Oak Ridge, Tennessee 37831
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Gebhart TE, Shiraki D, Baldzuhn J, Baylor LR, Meitner SJ. Design and Modeling of Vacuum Pumping for Steady-State Pellet Fueling Systems. Fusion Science and Technology 2018. [DOI: 10.1080/15361055.2018.1541399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - D. Shiraki
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - J. Baldzuhn
- Max Planck Institute for Plasma Physics, Greifswald, Germany
| | - L. R. Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
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Gebhart TE, Combs SK, Baylor LR. Comparison of an Electrothermal Plasma Source to a Light Gas Gun for Launching Large Cryogenic Pellets for Tokamak Disruption Mitigation. Fusion Science and Technology 2018. [DOI: 10.1080/15361055.2017.1372683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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)
| | - S. K. Combs
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - L. R. Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
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Combs SK, Reed JR, Lyttle MS, Baylor LR, Carmichael JR, Gebhart TE, Meitner SJ, Rasmussen DA. Gas Gun Model and Comparison to Experimental Performance of Pipe Guns Operating with Light Propellant Gases and Large Cryogenic Pellets. Fusion Science and Technology 2017. [DOI: 10.1080/15361055.2017.1333824] [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: 10/19/2022]
Affiliation(s)
- S. K. Combs
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - J. R. Reed
- University of Tennessee, Knoxville, Tennessee
| | - M. S. Lyttle
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - L. R. Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
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