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Kashiwagi M, Kisaki M, Saquilayan GQ, Kojima A, Hiratsuka J, Ichikawa M, Shimabukuro Y, Murayama M, Tobari H. Study of beamlets extracted from a multi-aperture and five-stage acceleration system. Rev Sci Instrum 2022; 93:053301. [PMID: 35649793 DOI: 10.1063/5.0080804] [Citation(s) in RCA: 1] [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] [Received: 12/03/2021] [Accepted: 03/12/2022] [Indexed: 06/15/2023]
Abstract
A beam optics study using the ITER-relevant high intense negative ion beams, such as 1 MeV, 200 A/m2, has been performed experimentally and analytically using a multi-aperture and five-stage accelerator. Initially, multi-beamlets generated from this accelerator were deflected in various directions due to the magnetic field and space charge repulsion between beams and showed various divergences. These had limited the pulse length and the beam energy. Compensation methods of the beamlet deflections have worked effectively and contributed to achieving the ITER requirement, the divergence angle of <7 mrad, and the deflection angle of <1 mrad for 1 MeV beam. The beam pulse has been gradually extended from 1 to 100 s and is now going to a longer pulse based on these results. One of the remaining issues is to understand and suppress peripheral components of the beam, namely, the halo, and to reduce the local heat loads observed around the aperture edge. This halo component has been successfully distinguished from the beam core by using a newly developed beam emittance measurement system for high intense beams. By combining this measured beam emittance and the beam simulation, it was clarified for the first time that the halo components are generated in an area of 1 mm width from the aperture edge.
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Affiliation(s)
- M Kashiwagi
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - M Kisaki
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - G Q Saquilayan
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - A Kojima
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - J Hiratsuka
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - M Ichikawa
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - Y Shimabukuro
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - M Murayama
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - H Tobari
- Fusion Energy Directorate, National Institutes for Quantum Science and Technology, Naka, Ibaraki 311-0193, Japan
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Clark E, Lumsdaine A, Ekici K, Ruggles A. Computational Investigation of the Thermal-Hydraulic Performance for Twisted Tape Enabled High Heat Flux Components. Fusion Science and Technology 2017. [DOI: 10.1080/15361055.2017.1333823] [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)
- E. Clark
- University of Tennessee, Knoxville, Knoxville, Tennessee 37996
| | - A. Lumsdaine
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - K. Ekici
- University of Tennessee, Knoxville, Knoxville, Tennessee 37996
| | - A. Ruggles
- University of Tennessee, Knoxville, Knoxville, Tennessee 37996
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Sharafat S, Mills A, Youchison D, Nygren R, Williams B, Ghoniem N. Ultra Low Pressure-Drop Helium-Cooled Porous-Tungsten PFC. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [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)
- S. Sharafat
- University of California Los Angeles, Los Angeles, CA. 90095-1597
| | - A. Mills
- University of California Los Angeles, Los Angeles, CA. 90095-1597
| | - D. Youchison
- Sandia National Laboratory, Albuquerque, NM 87185-1129
| | - R. Nygren
- Sandia National Laboratory, Albuquerque, NM 87185-1129
| | | | - N. Ghoniem
- University of California Los Angeles, Los Angeles, CA. 90095-1597
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Affiliation(s)
- Ronald D. Boyd
- Prairie View A&M University Roy G. Perry College of Engineering, Thermal Science Research Center Mail Stop 25250P.O. Box 519, Prairie View, Texas 77446-0519
| | - Aaron M. May
- Prairie View A&M University Roy G. Perry College of Engineering, Thermal Science Research Center Mail Stop 25250P.O. Box 519, Prairie View, Texas 77446-0519
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Ezato K, Suzuki S, Dairaku M, Akiba M. Critical heat flux experiments using a screw tube under DEMO divertor-relevant cooling conditions. Fusion Engineering and Design 2008. [DOI: 10.1016/j.fusengdes.2008.07.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ezato K, Suzuki S, Dairaku M, Akiba M. Experimental examination of heat removal limitation of screw cooling tube at high pressure and temperature conditions. Fusion Engineering and Design 2006. [DOI: 10.1016/j.fusengdes.2005.06.360] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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