Electrical and Electronic Engineering; Biochemistry; Instrumentation; Atomic and Molecular Physics, and Optics; Analytical Chemistry
Abstract :
[en] In this paper, we assess the effect of cryostat bridge vibrations on the plasma current measurement accuracy when using a fiber optic current sensor (FOCS) in ITER. The impact of vibrations on the light polarization state was first experimentally investigated using a miniaturized mock-up which represented a relevant part of the ITER FOCS structure. The set-up was then numerically simulated using the Jones matrix approach. Equivalent vibration matrices obtained from the experiment were used in the simulations to determine the effect of the vibrations on the FOCS accuracy. It is demonstrated that although the vibrations imply some changes in the polarization state, this effect can be strongly reduced when a proper low-birefringent spun optical fiber is used. The ITER requirement regarding the plasma current measurement accuracy can therefore be fulfilled.
Donné A.J.H. Costley A.E. Barnsley R. Bindslev H. Boivin R. Conway G. Fisher R. Giannella R. Hartfuss H. Von Hellermann M.G. et al. Chapter 7: Diagnostics Nuclear Fusion 2007 47 S337 S384 10.1088/0029-5515/47/6/S07
Vayakis G. Bertalot L. Encheva A. Walker C. Brichard B. Cheon M.S. Chitarin G. Hodgson E. Ingesson C. Ishikawa M. et al. Nuclear technology aspects of ITER vessel-mounted diagnostics J. Nucl. Mater. 2011 417 780 786 10.1016/j.jnucmat.2011.01.081
Spuig P. Defrasne P. Martin G. Moreau M. Moreau P. Saint-Laurent F. An analog integrator for thousand second long pulses in Tore Supra Fusion Eng. Des. 2003 66–68 953 957 10.1016/S0920-3796(03)00382-X
Moreau P. Brichard B. Fil A. Malard P. Pastor P. Le-Luyer A. Samaille F. Massaut V. Test of fiber optic based current sensors on the Tore Supra tokamak Fusion Eng. Devices 2011 86 1222 1226 10.1016/j.fusengdes.2010.12.023
Xue M. Shen B. Chen D. Wang Y. Shi T. Wang H. Sun Y. Qian J. Xiao H. Xiao B. Fiber-optic current sensor for plasma current on experimental advanced superconducting tokamak Fusion Eng. Devices 2019 140 11 15 10.1016/j.fusengdes.2019.01.070
Descamps F. Aerssens M. Gusarov A. Mégret P. Massaut V. Wuilpart M. Simulation of vibration-induced effect on plasma current measurement using a fiber optic current sensor Opt. Express 2014 22 14666 14680 10.1364/OE.22.014666 24977562
Wuilpart M. Vanus B. Andrasan A. Gusarov A. Moreau P. Mégret P. Study of a fibre optics current sensor for the measurement of plasma current in ITER Proceedings of the Sixth European Workshop on Optical Fibre Sensors (EWOFS’2016) Limerick, Ireland 31 May–3 June 2016 SPIE Bellingham, WA, USA 2016 Volume 9916
Barmenkov Y.O. Mendoza-Santoyo F. Faraday plasma current sensor with compensation for reciprocal birefringence induced by mechanicalperturbations J. Appl. Res. Technol. 2003 1 157 163 10.22201/icat.16656423.2003.1.02.614
Drexler P. Fiala P. Utilization of faraday mirror in fiber optic current sensors Radioengineering 2008 17 101 107
Aerssens M. Gusarov A. Brichard B. Massaut V. Mégret P. Wuilpart M. Faraday effect based optical fiber current sensor for tokamaks Proceedings of the 2011 2nd International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications Ghent, Belgium 6–9 June 2011 1 6
Zhang R. Yao X.S. Liu T. Li L. The Effect of Linear Birefringence on Fiber Optic Current Sensor Based on Faraday Mirror Proceedings of the SPIE/COS Photonics Asia Beijing, China 9 October 2014 SPIE Bellingham, WA, USA 2014 Volume 9274
Laming R.I. Payne D.N. Electric current sensors employing spun highly birefringent optical fibers J. Light. Technol. 1989 7 2084 2094 10.1109/50.41634
Galtarossa A. Grosso D. Palmieri L. Rizzo M. Spin-profile characterization in randomly birefringent spun fibers by means of frequency- domain reflectometry Opt. Lett. 2009 17 101 107 10.1364/OL.34.001078 19340225
J.Nemeth Structural Analysis of Cryostat Bridge Cable Trays under Seismic and VDE Loads 2019 Available online: https://user.iter.org/?uid=TVR76V (accessed on 17 August 2022)
Leysen W. Gusarov A. Wuilpart M. Beaumont P. Boboc A. Croft D. Bekris N. Batistoni P. Plasma current measurement at JET using polarimetry-based fibre optic current sensor Fusion Eng. Des. 2020 160 111754 10.1016/j.fusengdes.2020.111754
Gusarov A. Leysen W. Beaumont P. Wuilpart M. Dandu P. Boboc A. Croft D. Bekris N. Batistoni P. Performance assessment of plasma current measurement at JET using fibre optics current sensor Fusion Eng. Des. 2021 165 112228 10.1016/j.fusengdes.2021.112228
Gusarov A. Leysen W. Beaumont P. Boboc A. Wuilpart M. Dandu P. Croft D. Bekris N. Batistoni P. Long-term stability of the toroidal current measurement at JET using fibre optics current sensor J. Instrum. 2022 17 C04021 10.1088/1748-0221/17/04/C04021
Aerssens M. Descamps F. Gusarov A. Mégret P. Moreau P. Wuilpart M. Influence of the optical fiber type on the performances of fiber-optics current sensor dedicated to plasma current measurement in ITER Appl. Opt. 2015 54 5983 5991 10.1364/AO.54.005983 26193142
Gillooly A. Putting the world in a spin - Fibercore’s spun optical fibers for the current sensor industry Proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013 Hsinchu, Taiwan 6–9 July 2013 Volume 2 37 40
Yao P. Chen X. Hao P. Xiao H. Ding Z. Liu T. Steve Yao X. Introduction and measurement of the effective Verdet constant of spun optical fibers Opt. Express 2021 29 23315 23330 10.1364/OE.432418
Pistoni N.C. Martinelli M. Vibration-insensitive fiber-optic current sensor Opt. Lett. 1993 18 314 316 10.1364/OL.18.000314 19802121