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Ogawa K, Isobe M, Nuga H, Seki R, Ohdachi S, Osakabe M. Evaluation of Alpha Particle Emission Rate Due to the p- 11B Fusion Reaction in the Large Helical Device. Fusion Science and Technology 2022. [DOI: 10.1080/15361055.2021.1973294] [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: 11/04/2022]
Affiliation(s)
- K. Ogawa
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
- The Graduate University for Advanced Studies, Sokendai, Toki 509-5292, Japan
| | - M. Isobe
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
- The Graduate University for Advanced Studies, Sokendai, Toki 509-5292, Japan
| | - H. Nuga
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Seki
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
- The Graduate University for Advanced Studies, Sokendai, Toki 509-5292, Japan
| | - S. Ohdachi
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
- University of Tokyo, Tokyo 113-8654, Japan
| | - M. Osakabe
- National Institutes of Natural Sciences, National Institute for Fusion Science, Toki 509-5292, Japan
- The Graduate University for Advanced Studies, Sokendai, Toki 509-5292, Japan
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Kamio S, Fujiwara Y, Ogawa K, Kobayashi MI, Sangaroon S, Isobe M, Seki R, Nuga H, Osakabe M, Matsuyama S, Miwa M, Toyama S. Neutron-induced signal on the single crystal chemical vapor deposition diamond-based neutral particle analyzer. Rev Sci Instrum 2020; 91:113304. [PMID: 33261440 DOI: 10.1063/5.0020460] [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: 07/01/2020] [Accepted: 10/29/2020] [Indexed: 06/12/2023]
Abstract
A diamond-based neutral particle analyzer (DNPA) array composed of single-crystal chemical vapor deposition (sCVD) diamond detectors was installed on the Large Helical Device (LHD) for measuring the helically trapped energetic particles. In high neutron flux experiments, the unwanted neutron-induced pulse counting rate should be estimated using the neutron diagnostics because a diamond detector is sensitive to neutrons as well as energetic neutral particles. In order to evaluate the quantitative neutron-induced pulse counting rate on the DNPA, the response functions of the sCVD diamond detector for mono-energetic neutrons were obtained using accelerator-based D-D and D-7Li neutron sources in Fast Neutron Laboratory (FNL). As a result of the neutron flux estimation by the Monte Carlo N-Particle code at the NPA position in the LHD and the response function obtained in the FNL experiment, the counting rate of the neutron-induced signal was predicted to be 1.1 kcps for the source neutron emission rate of Sn = 1 × 1015 n/s. In the LHD experiment, the neutron-induced signals were observed by closing the gate valve during the plasma discharges. It is found that the counting rates of the neutron-induced signals proportional to Sn reached 1.1 kcps at Sn = 1 × 1015 n/s. As a result of the quantitative estimation of the neutron-induced signals on the DNPA using other neutron measurements, it has become possible to accurately measure energetic neutral particles in the high neutron flux experiment.
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Affiliation(s)
- S Kamio
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - Y Fujiwara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - K Ogawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - M I Kobayashi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - S Sangaroon
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - M Isobe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - R Seki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - H Nuga
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - M Osakabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - S Matsuyama
- Tohoku University, 6-6 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - M Miwa
- Tohoku University, 6-6 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - S Toyama
- Tohoku University, 6-6 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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Sangaroon S, Ogawa K, Isobe M, Kobayashi MI, Fujiwara Y, Kamio S, Seki R, Nuga H, Yamaguchi H, Osakabe M. Performance of the newly installed vertical neutron cameras for low neutron yield discharges in the Large Helical Device. Rev Sci Instrum 2020; 91:083505. [PMID: 32872928 DOI: 10.1063/5.0010302] [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: 04/13/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Two new vertical neutron cameras characterized by high detection efficiency were developed on the Large Helical Device in order to observe poloidal structures of helically trapped beam ions created by the perpendicularly injected positive-ion based neutral beam (P-NB) and are newly operated since 2018. In this work, the neutron fields at the vertical neutron cameras are investigated using the Monte Carlo N-particle transport code to evaluate the performance of its collimators. The results indicate that neutrons are attenuated by the heavy concrete and are well collimated through the collimator to detectors. Neutron spectra at the detector position show over 99% of uncollided 2.45 MeV neutrons. Time evolution of neutron emission profiles during the short pulse of P-NB injection is measured by the vertical neutron cameras. Peaks on the neutron emission profiles corresponding to the helically trapped beam ion are successfully obtained, as designed. The decrease in line integrated neutron flux at the peak positions after the P-NB stops is consistent with the behavior of the total neutron emission rate measured by the neutron flux monitor.
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Affiliation(s)
- S Sangaroon
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - K Ogawa
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - M Isobe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - M I Kobayashi
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - Y Fujiwara
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - S Kamio
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - R Seki
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - H Nuga
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - H Yamaguchi
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
| | - M Osakabe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
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Ejiri A, Oosako T, Tsujimura J, Shimada Y, Takase Y, Torii Y, Sasaki M, Tojo H, Masuda T, Nuga H, Sumitomo N, Kainaga S, Sugiyama J, Tsujii N. ECH and HHFW Start-Up Experiments on the TST-2 Spherical Tokamak. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [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)
- A. Ejiri
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - T. Oosako
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - J. Tsujimura
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - Y. Shimada
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - Y. Takase
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - Y. Torii
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - M. Sasaki
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - H. Tojo
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - T. Masuda
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - H. Nuga
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - N. Sumitomo
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - S. Kainaga
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - J. Sugiyama
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
| | - N. Tsujii
- Grad. School of Frontier Sciences and Grad. School of Science, the Univ. Tokyo, Kashiwa 277-8561, Japan
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