Abstract
The gas flow in the neutralization region affects the neutralization efficiency as well as the beam transition efficiency of whole neutral beam injector, which will be applied as a high power auxiliary heating and non-inductive current driver system for the Experimental Advanced Superconducting Tokamak (EAST). The neutralization region of EAST neutral beam injector includes not only the gas cell neutralizer in traditional sense, but also part of the ion source downstream the electrode grid, the gate valve, and the transitional piping and fitting. The gas flow in this neutralization region has been modeled and researched using an adjusted Direct Simulation Monte Carlo code to understand the formation mechanism of gas target thickness, which determines the neutralization efficiency. This paper presents the steady-state, viscous and transition region flowfields, the gas density distribution and the various centerline profiles including Knudsen number, temperature, pressure and axial velocity by injected the deuterium gas from the arc chamber and neutralizer, respectively. The target thickness in the neutralization region as a function of gas inlet quantity is also given in the absence of beam for future operation of EAST neutral beam injector.
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Y.-X. Wan, Overview progress and future plan of EAST project, presented at 21st IAEA fusion energy conference (Chengdu, China, 2006)
C.-D. Hu, NBI team, Conceptual design of EAST neutral beam injection system, presented at 14th Chinese Nuclear Physics Conference (Hefei, China, 2010); see also Plasma Sci. Technol. (in press)
K.H. Berkner, R.V. Plye, J.W. Stearns, Intense, mixed-energy hydrogen beams for CTR injection. Nucl. Fusion 15, 249 (1975)
J. Kim, H.H. Haselton, Analysis of particle species evolution in neutral-beam injection lines. J. Appl. Phys. 50, 3802 (1979)
J.-L. Wei, C.-D. Hu, L.-Z. Liang, Monte Carlo simulation for the beam deflection in the EAST neutralizer due to stray magnetic field. Fusion Sci. Technol. 61, 209 (2012)
L.-Z. Liang, C.-D. Hu, Y.-L. Xie, Y.-H. Xie, NBI team, Modeling process of the neutral beam re-ionization loss. Chin. Phys. C 34, 972 (2010)
J.-L. Wei, C.-D. Hu, L.-Z. Liang, Z.-W. Liu, Modeling the gas flow in the neutralizer of neutral beam injector using Direct Simulation Monte Carlo approach. Fusion Eng. Des. (2012)
G.A. Bird, Molecular Gas Dynamics and the Direct Simulation of Gas Flows (Clarendon Press, Oxford, UK, 1994)
C.-D. Hu, Y.-H. Xie, S. Liu, Y.-L. Xie, C.-C. Jiang, S.-H. Song, J. Li, Z.-M. Liu, First plasma of megawatt high current ion source for neutral beam injector of the experimental advanced superconducting tokamak on the test bed. Rev. Sci. Instrum. 82, 023303 (2011)
C.-D. Hu, Y.-L. Xie, NBI team, the development of a megawatt-level high current ion source. Plasma Sci. Technol. 14, 75 (2012)
Y.-H. Xie, C.-D. Hu, S. Liu, C.-C. Jiang, J. Li, L.-Z. Liang, NBI team, arc discharge regulation of a megawatt hot cathode bucket ion source for the experimental advanced superconducting tokamak neutral beam injector. Rev. Sci. Instrum. 83, 013301 (2012)
L. Tao, Y.-L. Xie, C.-D. Hu, Z.-M. Liu, NBI team, numerical analysis of a cooling system for high heat flux components in the neutral beam injection system. Fusion Eng. Des. 85, 2095 (2010)
C.-D. Hu, L.-Z. Liang, Y.-L. Xie, J.-L. Wei, Y.-H. Xie, J. Li, Z.-M. Liu, S. Liu, C.-C. Jiang, P. Sheng, Y.-J. Xu, Design of neutral beam-line of EAST. Plasma Sci. Technol. 13, 541 (2011)
A.P. Colleraine, D.W. Doll, M.M. Holland, J.H. Kamperschroer, K. Berkner, K. Halbach, L. Resnick, A.J. Cole, A parametric study of the doublet III neutral beam injection system, presented at the 10th symposium on Fusion Technology (SOFT). (Padua, Italy, 1978)
L.-Z. Liang, C.-D. Hu, Y.-L. Xie, Q. Guo, Y.-H. Xie, Calculation of beam intensity distribution for the neutral beam injection in EAST. Plasma Sci. Technol. 13, 502 (2011)
J.-L. Wei, C.-D. Hu, L.-Z. Liang, J. Li, Simulation of the gas flow in the multi-slot electrode system of ion source for EAST neutral beam injector. Plasma Sci. Technol. (2012)
J. Paméla, Gas heating effects in the neutralizers of neutral beam injection lines. Rev. Sci. Instrum. 57, 1066 (1986)
E. Surrey, B. Crowley, Spectroscopic measurement of gas temperature in the neutralizer of the JET neutral beam injection system. Plasma Phys. Control. Fusion 45, 1209 (2003)
E. Surrey, C.D. Challis, D. Ciric, S.J. Cox, B. Crowley, I. Jenkins, T.T.C. Jones, D. Keeling, Measurement of the depletion of neutraliser target due to gas heating in the JET neutral beam injection system. Fusion Eng. Des. 73, 141 (2005)
M. Porton, E. Surrey, Efficiency of neutral beam neutralizers in JET and ITER. Fusion Eng. Des. 86, 797 (2011)
Y.-J. Xu, C.-D. Hu, Y.-L. Xie, Q. Guo, L. Tao, Calculation of beam extraction pulse duration for beam angular divergence measurement of EAST neutral beam injection. J. Fusion Energ. 29, 395 (2010)
Y.-J. Xu, C.-D. Hu, Y.-L. Xie, Z.-M. Liu, Y.-H. Xie, L.-Z. Liang, L. Yu, A calculation model of beam power based on thermocouple for EAST neutral beam injector. J. Fusion Energ. 30, 347 (2011)
Acknowledgments
The authors acknowledge the suggestions and fruitful discussions with Dr. R. M. Hong of General Atomics, San Diego, USA. This work was supported by National Natural Science Foundation of China (No. 11075183) and the Chinese Academy of Sciences Knowledge Innovation Project (the study and simulation on beam interaction with background particles in neutralization area for NBI).
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Wei, JL., Hu, CD., Liang, LZ. et al. Gas Flow in the Neutralization Region of EAST Neutral Beam Injector. J Fusion Energ 32, 196–202 (2013). https://doi.org/10.1007/s10894-012-9548-y
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DOI: https://doi.org/10.1007/s10894-012-9548-y