Abstract
A real-time double-ring neutron time-of-flight (TOFII) spectrometer system has been proposed to achieve plasma diagnosis on HL-2M tokamak with a relatively high count rate and sufficient energy resolution. The TOFII system is in its development stage, and this work describes its characteristics in terms of design principle, system structure, electronic system design, preliminary tests, and neutron transport simulation. The preliminary test results illustrate that the TOFII system can demonstrate the real-time dynamic spectrum every 10 ms. The results also show that based on the support vector machine method, the n–γ discrimination algorithm achieves the discrimination accuracy of 99.1% with a figure of merit of 1.30, and the intrinsic timing resolution of the system is within 0.3%. The simulated flight time spectrums from 1 to 5 MeV are obtained through the Monte Carlo tool Geant4, which also provide the reasonable results. The TOFII system will then be calibrated on mono-energetic neutron sources for further verification.
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M.G. Johnson, L. Giacomelli, A. Hjalmarsson et al., The 2.5-MeV neutron time-of-flight spectrometer TOFOR for experiments at JET. Nucl. Instrum. Methods A. 591, 417–430 (2008). https://doi.org/10.1016/j.nima.2008.03.010
Y. Shibata, T. Iguchi, Time-of-flight neutron spectrometer for JT-60U. Rev. Sci. Instrum. 72, 828 (2001). https://doi.org/10.1063/1.1323240
A. Hjalmarsson, S. Conroy, G. Ericsson et al., The TOFOR spectrometer for 2.5 MeV neutron measurements at JET. Rev. Sci. Instrum. 74, 1750 (2003). https://doi.org/10.1063/1.1534401
C. Guerrero, A. Tsinganis, E. Berthoumieux et al., Performance of the neutron time-of-flight facility n TOF at CERN. Eur. Phys. J. A 49, 27 (2013). https://doi.org/10.1140/epja/i2013-13027-6
X. Zhang, J. Källne, G. Gorini et al., Second generation fusion neutron time-of-flight spectrometer at optimized rate for fully digital data acquisition. Rev. Sci. Instrum. 85, 043503 (2014). https://doi.org/10.1063/1.4869804
W. Zhang, T. Wu, B. Zheng et al., A real-time neutron–gamma discriminator based on the support vector machine method for the time-of-flight neutron spectrometer. Plasma Sci. Technol. 20, 045601 (2018). https://doi.org/10.1088/2058-6272/aaaaa9
Q. Li, The component development status of HL-2M tokamak. Fusion Eng. Des. 82, 561–566 (2007). https://doi.org/10.1016/j.fusengdes.2015.06.106
D.Q. Liu, H. Ran, G.S. Li et al., Engineering design for the HL-2M tokamak components. Fusion Eng. Des. 88, 679–682 (2013). https://doi.org/10.1016/j.fusengdes.2013.04.035
D. Liu, T. Lin, T. Qiao et al., Assembly study for HL-2M tokamak. Fusion Eng. Des. 96–97, 298–301 (2015). https://doi.org/10.1016/j.fusengdes.2015.06.026
D. Liu, C. Zhou, Z. Cao et al., Construction of the HL-2A tokamak. Fusion Eng. Des. 66–68, 147 (2003). https://doi.org/10.1016/S0920-3796(03)00165-0
Q. Li, Brief introduction to engineering and experiment of HL-2A tokamak. At. Energy Sci. Technol. 43, 204 (2009). (in Chinese)
Y. Liu, X. Ding, Q. Yang et al., Recent advances in the HL-2A tokamak experiments. Nucl. Fusion 45, S239–S244 (2005). https://doi.org/10.1088/0029-5515/45/10/S19
G.C. Neilson, D.B. James, Time of flight spectrometer for fast neutrons. Rev. Sci. Instrum. 26, 1018 (1955). https://doi.org/10.1063/1.1715178
G.J.F. Legge, P. Van der Merwe, A double scatter neutron spectrometer. Nucl. Instrum. Methods 63, 157–165 (1968). https://doi.org/10.1016/0029-554X(68)90321-2
G. Gorini, J. Källne, High count rate time-of-flight spectrometer for DD fusion neutrons. Rev. Sci. Instrum. 63, 4548 (1992). https://doi.org/10.1063/1.1143663
S. Agostinelli, J. Allison, K. Amako et al., Geant4: a simulation toolkit. Nucl. Instrum. Methods A 506, 250–303 (2003). https://doi.org/10.1016/S0168-9002(03)01368-8
Q. Tang, Z. Zhao, M. Su et al., Performance calculation of ultra fast neutron scintillator. High Power Laser Part. Beams 22, 1243 (2010). https://doi.org/10.3788/HPLPB20102206.1243. (in Chinese)
H. Liu, Development and application of the PXI technology. Meas. Control Technol. 25, 51–53 (2006). https://doi.org/10.1007/s10614-006-9021-y. (in Chinese)
J. Christiansen, HPTDC high performance time to digital converter version 2.1 CERN/EP-MIC, CERN, Geneva (2002). http://cds.cern.ch/record/1067476
W. Fan, B. Zheng, J. Cao et al., Development of a fast electron bremsstrahlung diagnostic system based on LYSO and silicon photomultipliers during lower hybrid current drive for tokamak. Plasma Sci. Technol. 21, 065104 (2019). https://doi.org/10.1088/2058-6272/ab0a77
M.G. Johnson, S. Conroy, M. Cecconello et al., Modelling and TOFOR measurements of scattered neutrons at JET. Plasma Phys. Control. Fusion. 52, 085002 (2010). https://doi.org/10.1088/0741-3335/52/8/085002
S.A. Pozzi, M.M. Bourne, S.D. Clarke, Pulse shape discrimination in the plastic scintillator EJ-299-33. Nucl. Instrum. Methods A 723, 19–23 (2013). https://doi.org/10.1016/j.nima.2013.04.085
E.V. Pagano, M.B. Chatterjee, E. De Filippo et al., Pulse shape discrimination of plastic scintillator EJ 299-33 with radioactive sources. Nucl. Instrum. Methods A 889, 83–88 (2018). https://doi.org/10.1016/j.nima.2018.02.010
M.J. Joyce, M.D. Aspinall, F.D. Cave et al., The design, build and test of a digital analyzer for mixed radiation fields. IEEE Trans. Nucl. Sci. 57, 2625–2630 (2010). https://doi.org/10.1109/TNS.2010.2044245
M.D. Aspinalla, B. D’Mellowa, R.O. Mackina et al., The empirical characterization of organic liquid scintillation detectors by the normalized average of digitized pulse shapes. Nucl. Instrum. Methods A 578, 261–266 (2007). https://doi.org/10.1016/j.nima.2007.05.114
V. Vapnik, Estimation of Dependences Based on Empirical Data (Springer, New York, 2006). https://doi.org/10.1007/0-387-34239-7
C. Cortes, V. Vapnik, Support-vector networks. Mach. Learn. 20, 273–297 (1995). https://doi.org/10.1007/BF00994018
C.J.C. Burges, A tutorial on support vector machines for pattern recognition. Data Min. Knowl. Discov. 2, 121–167 (1998). https://doi.org/10.1023/A:1009715923555
S. Liu, C. Feng, Q. An et al., BES III time-of-flight readout system. IEEE Trans. Nucl. Sci. 57, 419–427 (2010). https://doi.org/10.1109/TNS.2009.2034520
G.S. Gao, R. Partridge, High speed digital TDC for D0 vertex reconstruction. IEEE Trans. Nucl. Sci. 38, 286–289 (1991). https://doi.org/10.1109/23.289311
Z. Kohley, E. Lunderberg, P.A. DeYoung et al., Modeling interactions of intermediate-energy neutrons in a plastic scintillator array with GEANT4. Nucl. Instrum. Methods A 682, 59–65 (2012). https://doi.org/10.1016/j.nima.2012.04.060
S.F. Naeem, S.D. Clarke, S.A. Pozzi, Validation of Geant4 and MCNPX-PoliMi simulations of fast neutron detection with the EJ-309 liquid scintillator. Nucl. Instrum. Methods A. 714, 98–104 (2013). https://doi.org/10.1016/j.nima.2013.02.017
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This work was partially supported by the National Science and Technology Major Project of Ministry of Science and Technology of China (Nos. 2014GB109003 and 2015GB111002) and the National Natural Science Foundation of China (Nos. 11375195, 11575184, 11375004, and 11775068).
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Zheng, BW., Zhang, W., Wu, TY. et al. Development of the real-time double-ring fusion neutron time-of-flight spectrometer system at HL-2M. NUCL SCI TECH 30, 175 (2019). https://doi.org/10.1007/s41365-019-0702-3
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DOI: https://doi.org/10.1007/s41365-019-0702-3