Development of the real-time double-ring fusion neutron time-of-flight spectrometer system at HL-2M
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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.
Keywords
Time-of-light Neutron spectrometer Geant4 HL-2MReferences
- 1.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 CrossRefGoogle Scholar
- 2.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 CrossRefGoogle Scholar
- 3.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 CrossRefGoogle Scholar
- 4.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 CrossRefGoogle Scholar
- 5.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 CrossRefGoogle Scholar
- 6.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 CrossRefGoogle Scholar
- 7.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 CrossRefGoogle Scholar
- 8.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 CrossRefGoogle Scholar
- 9.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 CrossRefGoogle Scholar
- 10.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 CrossRefGoogle Scholar
- 11.Q. Li, Brief introduction to engineering and experiment of HL-2A tokamak. At. Energy Sci. Technol. 43, 204 (2009). (in Chinese) Google Scholar
- 12.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 CrossRefGoogle Scholar
- 13.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 CrossRefGoogle Scholar
- 14.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 CrossRefGoogle Scholar
- 15.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 CrossRefGoogle Scholar
- 16.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 CrossRefGoogle Scholar
- 17.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) CrossRefGoogle Scholar
- 18.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) CrossRefGoogle Scholar
- 19.J. Christiansen, HPTDC high performance time to digital converter version 2.1 CERN/EP-MIC, CERN, Geneva (2002). http://cds.cern.ch/record/1067476
- 20.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 CrossRefGoogle Scholar
- 21.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 CrossRefGoogle Scholar
- 22.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 CrossRefGoogle Scholar
- 23.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 CrossRefGoogle Scholar
- 24.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 CrossRefGoogle Scholar
- 25.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 CrossRefGoogle Scholar
- 26.V. Vapnik, Estimation of Dependences Based on Empirical Data (Springer, New York, 2006). https://doi.org/10.1007/0-387-34239-7 CrossRefzbMATHGoogle Scholar
- 27.C. Cortes, V. Vapnik, Support-vector networks. Mach. Learn. 20, 273–297 (1995). https://doi.org/10.1007/BF00994018 CrossRefzbMATHGoogle Scholar
- 28.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 CrossRefGoogle Scholar
- 29.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 CrossRefGoogle Scholar
- 30.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 CrossRefGoogle Scholar
- 31.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 CrossRefGoogle Scholar
- 32.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 CrossRefGoogle Scholar