Surface heat flux estimation with embedded thermocouples and Fiber Bragg Grating sensor in ITER-like plasma facing components

Y. Anquetin (1) , J. Gaspar (1) , Y. Corre (2) , Q. Tichit (2) , J. L. Gardarein (1) , Guillaume Laffont (3) , M. Missirlian (2) , C. Pocheau (2)

1 IUSTI - Institut universitaire des systèmes thermiques industriels
2 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique
3 LCFO (CEA, LIST) - Laboratoire Capteurs Fibres Optiques (CEA, LIST)

The main objective of WEST is to study the behavior of the ITER-like divertor monobloc components, test their resistance and ageing under ITER relevant heat loads. For the upcoming phase 2 of WEST, the lower divertor is now fully equipped with the ITER-like actively cooled bulk tungsten Plasma Facing Units (PFU), designed to withstand 10MW/m2 in steady state. This divertor is also equipped with an enlarged set of ThermoCouples (TCs x 16) and Fiber Bragg Gratings (FBGs) probes (x5) with 14 measurement spots each to evaluate the heat loading during the experiments. This paper presents the new TC and FBG diagnostics as well as the associated inverse method used to estimate the surface heat flux from the embedded temperature measurements in the divertor. The performance of each diagnostic will be evaluated with synthetic measurements generated with realistic heat flux intensity and distribution. The results of a parametrical analysis shows that each diagnostic is able to estimate the spatial distribution of the expected heat fluxes in WEST

Keywords: instrumentation; ITER; WEST; tokamak; divertor; plasma; temperature measurement; Optical Fiber Sensor; Fiber Bragg Grating; Distributed and Quasi-distributed sensing; heat flux; Signal processing

Domains: Plasma Physics [physics.plasm-ph]; Instrumentation and Detectors [physics.ins-det]; Optics / Photonic

Y. Anquetin, J. Gaspar, Y. Corre, Q. Tichit, J. L. Gardarein, et al.. Surface heat flux estimation with embedded thermocouples and Fiber Bragg Grating sensor in ITER-like plasma facing components. Fusion Engineering and Design, 2023, 190, pp.113480. ⟨10.1016/j.fusengdes.2023.113480⟩. ⟨cea-04087288⟩