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Parr E, McClements KG, Heidbrink WW, Michael CA, Prechel G, Rivero-Rodriguez JF. Studying fast-ion populations using oscillations in solid-state neutral-particle analyzer signal and neutral-beam injection power. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:013508. [PMID: 38230994 DOI: 10.1063/5.0178179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/18/2023] [Indexed: 01/18/2024]
Abstract
A method for determining the fast-ion population density in magnetically confined plasmas as a function of pitch-radius, (λ, R), using a solid-state neutral-particle analyzer (ssNPA) signal and neutral-beam injection (NBI) power-output data has been developed. Oscillations in the NBI power output are replicated only in the active part of the ssNPA signal, allowing this to be separated from the passive and background signals, which usually complicate data from this diagnostic. Results obtained using this method are compared with those from standard techniques using data from the Mega-Amp Spherical Tokamak Upgrade spherical tokamak.
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Affiliation(s)
- E Parr
- UKAEA, Culham Science Centre, Oxfordshire OX14 3DB, United Kingdom
| | - K G McClements
- UKAEA, Culham Science Centre, Oxfordshire OX14 3DB, United Kingdom
| | - W W Heidbrink
- University of California Irvine, Irvine, California 92697, USA
| | - C A Michael
- University of California, Los Angeles, California 90095, USA
| | - G Prechel
- University of California Irvine, Irvine, California 92697, USA
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2
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Yuan G, Wen Z, Feng L, Luo X, Wei L, Zhang J, Zhao W, Yang Q, Liu Y. Development of a D-D neutron spectrum detector based on helium-3 proportional counter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:113503. [PMID: 37921520 DOI: 10.1063/5.0159707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
Deuterium-deuterium (D-D) neutron spectrum diagnostics in tokamaks are a challenging task with current technologies. To address this issue, we designed and tested a fast and compact helium-3 proportional counter with a diameter of 2.5 cm and an effective length of 15 cm and using Kr as a stopping gas. The detector achieved a resolution of 96 keV for 2.406 MeV neutrons with a pulse shaping of 2 µs. Test results indicate that this detector has the potential to form a D-D neutron spectrometer for tokamaks, composed of detector arrays.
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Affiliation(s)
- Guoliang Yuan
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Zuowei Wen
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Lei Feng
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Xiaobing Luo
- Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610065, Sichuan, China
| | - Lingfeng Wei
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Jinwen Zhang
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Wei Zhao
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Qingwei Yang
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
| | - Yi Liu
- Southwestern Institute of Physics, Chengdu 610225, Sichuan, China
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Ogawa K, Isobe M, Nishitani T, Kobuchi T. The large helical device vertical neutron camera operating in the MHz counting rate range. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:113509. [PMID: 30501311 DOI: 10.1063/1.5054818] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
In the currently performed neutral beam (NB) -heated deuterium plasma experiments, neutrons are mainly produced by a beam-plasma reaction. Therefore, time-resolved measurement of the neutron emission profile can enhance the understanding of the classical and/or anomalous transport of beam ions. To measure radial neutron emission profiles as a function of time, the vertical neutron camera (VNC) capable of operation with a counting rate in the MHz range was newly installed on the Large Helical Device (LHD). This is the world's first neutron camera for stellarator/heliotron devices. The VNC consists of a multichannel collimator, eleven fast-neutron detectors, and the digital-signal-processing-based data acquisition system (DAQ). The multichannel collimator having little cross talk was made from hematite-doped heavy concrete, which has a high shielding performance against both neutrons and gamma-rays. A stilbene crystal coupled with a photomultiplier having high-gain-stability in the high-count rate regime was utilized as a fast-neutron scintillation detector because it has a high neutron-gamma discrimination capability at high count rates. The DAQ system equipped with a field programmable logic controller was developed to obtain the waveform acquired with a 1 GHz sampling rate and the shaping parameter of each pulse simultaneously at up to 106 cps (counts per second). Neutron emission profiles were successfully obtained in the first deuterium campaign of LHD in 2017. The neutron emission profile was measured in tangentially co-injected NB-heated plasma with different magnetic axes (R ax). The neutron counts became larger in the inward-shifted configuration, which was consistent with the total neutron rate measured by the neutron flux monitor. The radial peak position of the line-integrated neutron profile which changed according to R ax showed that the VNC worked successfully as designed. The VNC demonstrated the expected performance conducive to extending energetic-particle physics studies in LHD.
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Affiliation(s)
- K Ogawa
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - M Isobe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - T Nishitani
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - T Kobuchi
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
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Zhong GQ, Hu LQ, Pu N, Zhou RJ, Xiao M, Cao HR, Zhu YB, Li K, Fan TS, Peng XY, Du TF, Ge LJ, Huang J, Xu GS, Wan BN. Status of neutron diagnostics on the experimental advanced superconducting tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D820. [PMID: 27910514 DOI: 10.1063/1.4960814] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Neutron diagnostics have become a significant means to study energetic particles in high power auxiliary heating plasmas on the Experimental Advanced Superconducting Tokamak (EAST). Several kinds of neutron diagnostic systems have been implemented for time-resolved measurements of D-D neutron flux, fluctuation, emission profile, and spectrum. All detectors have been calibrated in laboratory, and in situ calibration using 252Cf neutron source in EAST is in preparation. A new technology of digitized pulse signal processing is adopted in a wide dynamic range neutron flux monitor, compact recoil proton spectrometer, and time of flight spectrometer. Improvements will be made continuously to the system to achieve better adaptation to the EAST's harsh γ-ray and electro-magnetic radiation environment.
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Affiliation(s)
- G Q Zhong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - L Q Hu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - N Pu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - R J Zhou
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - M Xiao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - H R Cao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Y B Zhu
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - K Li
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - T S Fan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing, China
| | - X Y Peng
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing, China
| | - T F Du
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing, China
| | - L J Ge
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - G S Xu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - B N Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
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Capecchi WJ, Anderson JK, Bonofiglo PJ, Kim J, Sears S. A collimated neutron detector for RFP plasmas in MST. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D826. [PMID: 27910571 DOI: 10.1063/1.4961304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The neutron emissivity profile in the Madison Symmetric Torus is being reconstructed through the use of a collimated neutron detector. A scintillator-photomultiplier tube (PMT) system is employed to detect the fusion neutrons with the plasma viewing volume defined by a 55 cm deep, 5 cm diameter aperture. Effective detection of neutrons from the viewing volume is achieved through neutron moderation using 1300 lbs of high density polyethylene shielding, which modeling predicts attenuates the penetrating flux by a factor of 104 or more. A broad spectrum of gamma radiation is also present due to the unconfined fusion proton bombardment of the thick aluminum vacuum vessel. A 15 cm cylindrical liquid scintillator of 3.8 cm diameter is used to further increase directional sensitivity. A fast (5 ns rise time) preamplifier and digitization at 500 MHz prevent pulse pile-up even at high count rates (∼104/s). The entire neutron camera system is situated on an adjustable inclining base which provides the differing plasma viewing volumes necessary for reconstruction of the neutron emissivity profile. This profile, directly related to the fast-ion population, allows for an investigation of the critical fast-ion pressure gradient required to destabilize a neutral beam driven Alfvénic mode which has been shown to transport fast ions.
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Affiliation(s)
- W J Capecchi
- University of Wisconsin- Madison, Madison, Wisconsin 53706, USA
| | - J K Anderson
- University of Wisconsin- Madison, Madison, Wisconsin 53706, USA
| | - P J Bonofiglo
- University of Wisconsin- Madison, Madison, Wisconsin 53706, USA
| | - J Kim
- University of Wisconsin- Madison, Madison, Wisconsin 53706, USA
| | - S Sears
- University of Wisconsin- Madison, Madison, Wisconsin 53706, USA
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Zhang YP, Yang JW, Liu Y, Fan TS, Luo XB, Yuan GL, Zhang PF, Xie XF, Song XY, Chen W, Ji XQ, Li X, Du TF, Ge LJ, Fu BZ, Isobe M, Song XM, Shi ZB, Yang QW, Duan XR. Development of the radial neutron camera system for the HL-2A tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:063503. [PMID: 27370450 DOI: 10.1063/1.4953109] [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 new radial neutron camera system has been developed and operated recently in the HL-2A tokamak to measure the spatial and time resolved 2.5 MeV D-D fusion neutron, enhancing the understanding of the energetic-ion physics. The camera mainly consists of a multichannel collimator, liquid-scintillation detectors, shielding systems, and a data acquisition system. Measurements of the D-D fusion neutrons using the camera have been successfully performed during the 2015 HL-2A experiment campaign. The measurements show that the distribution of the fusion neutrons in the HL-2A plasma has a peaked profile, suggesting that the neutral beam injection beam ions in the plasma have a peaked distribution. It also suggests that the neutrons are primarily produced from beam-target reactions in the plasma core region. The measurement results from the neutron camera are well consistent with the results of both a standard (235)U fission chamber and NUBEAM neutron calculations. In this paper, the new radial neutron camera system on HL-2A and the first experimental results are described.
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Affiliation(s)
- Y P Zhang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - J W Yang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Yi Liu
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - T S Fan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - X B Luo
- Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610041, China
| | - G L Yuan
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - P F Zhang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - X F Xie
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - X Y Song
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - W Chen
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - X Q Ji
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - X Li
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - T F Du
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - L J Ge
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - B Z Fu
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - M Isobe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5259, Japan
| | - X M Song
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Z B Shi
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - Q W Yang
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
| | - X R Duan
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
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Xie X, Chen Z, Peng X, Yuan X, Zhang X, Gorini G, Cui Z, Du T, Hu Z, Li T, Fan T, Chen J, Li X, Zhang G, Yuan G, Yang J, Yang Q. Neutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:103506. [PMID: 25362392 DOI: 10.1063/1.4896120] [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
Neutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector is described. The detector was placed at a location with little structure material in the field of view, and equipped with a gain monitoring system which could provide the possibility to evaluate the gain variation as well as to correct for the detector response. Time trace of the neutron emissivity was obtained and it was consistent with the result of a standard (235)U fission chamber. During the plasma discharge the neutron yield could vary by about four orders of magnitude and the fluctuation of the detector gain was up to about 6%. Pulse height spectrum of the liquid scintillation detector was constructed and corrected with the aid of the gain monitoring system, and the correction was found to be essential for the assessment of the neutron energy spectrum. This successful measurement offered experience and confidence for the application of liquid scintillation detectors in the upcoming neutron camera system.
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Affiliation(s)
- Xufei Xie
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Zhongjing Chen
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Xingyu Peng
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Xi Yuan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Xing Zhang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Giuseppe Gorini
- Dipartimento di Fisica 'G. Occhialini', Universita degli Studi di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - Zhiqiang Cui
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Tengfei Du
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Zhimeng Hu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Tao Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Tieshuan Fan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Jinxiang Chen
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Xiangqing Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Guohui Zhang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China
| | - Guoliang Yuan
- Southwestern Institute of Physics, 610000 Chengdu, China
| | - Jinwei Yang
- Southwestern Institute of Physics, 610000 Chengdu, China
| | - Qingwei Yang
- Southwestern Institute of Physics, 610000 Chengdu, China
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Zhang X, Yuan X, Xie X, Chen Z, Peng X, Chen J, Zhang G, Li X, Fan T, Zhong G, Hu L, Wan B. A compact stilbene crystal neutron spectrometer for EAST D-D plasma neutron diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:033506. [PMID: 23556820 DOI: 10.1063/1.4797623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new compact stilbene crystal neutron spectrometer has been investigated and applied in the neutron emission spectroscopy on the EAST tokamak. A new components analysis method is presented to study the anisotropic light output in the stilbene crystal detector. A Geant4 code was developed to simulate the neutron responses in the spectrometer. Based on both the optimal light output function and the fitted pulse height resolution function, a reliable neutron response matrix was obtained by Geant4 simulations and validated by 2.5 MeV and 14 MeV neutron measurements at a 4.5 MV Van de Graaff accelerator. The spectrometer was used to diagnose the ion temperature in plasma discharges with lower hybrid wave injection and ion cyclotron resonance heating on the EAST tokamak.
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Affiliation(s)
- Xing Zhang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing, China
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Sangaroon S, Cecconello M, Conroy S, Weiszflog M, Turnyanskiy M, Wodniak I, Ericsson G. Validation of neutron emission profiles in MAST with a collimated neutron monitor. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D910. [PMID: 23126913 DOI: 10.1063/1.4732059] [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 neutron camera with liquid scintillator detectors is used in MAST to measure the neutron emissivity from D(d,n)(3)He reactions along collimated lines of sight. In this work, the measured recoil proton pulse height spectra generated in the detectors by the incident neutrons is modelled taking into account the energy spectrum of the generated neutrons, their spatial distribution and transport to the detectors as well as the detector's response function. The contribution of scattered neutrons to the pulse height spectrum is also modelled. Good agreement is found between the experimental data and the simulations. Examples are given showing the sensitivity of the recoil proton pulse height spectra to different observation angles with respect the neutral beam injection and the plasma rotation direction.
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Affiliation(s)
- S Sangaroon
- Department of Physics and Astronomy, Uppsala University, EURATOM-VR Association, Sweden.
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