Reconstruction of hollow areas in density profiles from frequency swept reflectometry  

作　　者：Rennan B MORALES Stéphane HEURAUX Roland SABOT Sébastien HACQUIN Frédéric CLAIRET the Tore Supra Team 

机构地区：[1]United Kingdom Atomic Energy Authority,Culham Centre for Fusion Energy,Culham Science Centre,Abingdon,Oxon,OX143DB,United Kingdom [2]IJL,UMR CNRS,University of Lorraine,BP50840,Nancy,F-54011,France [3]Institute of Physics,University of Sao Paulo,Sao Paulo 05315-970,Brazil [4]IRFM,CEA,Cadarache,F-13108 Saint-Paul-lez-Durance,France [5]EUROfusion Programme Management Unit,Culham Science Centre,Culham OX143DB,United Kingdom

出　　处：《Plasma Science and Technology》2020年第6期32-40,共9页等离子体科学和技术（英文版）

基　　金：carried out with the support of the Brazilian National Council for Scientific and Technological Development(CNPq)under the Science Without Borders programme,within the framework of the French Federation for Magnetic Fusion Studies(FR-FCM)and of the EUROfusion consortium with funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No.633053;part-funded by the RCUK Energy Programme grant number EP/P012450/1。

摘　　要：The standard density profile reconstruction techniques are based on the WKB approximation of the probing wave’s phase,making them unable to properly reconstruct blind areas in the cut-off frequency profile.The reconstruction suffers a significant immediate error that is not rapidly damped.It is demonstrated that even though no reflections occur inside the hollow region causing the blind area,the higher probing frequencies that propagate through it carry information that can be used to estimate its properties.The usually ignored full-wave effects were investigated with the use of full-wave simulations in 1 D,with special attention paid to the frequency band where they are dominant.A database of perturbation signals was simulated onfive-dimensions of parameters and an application of the database inversion was demonstrated for a magnetic island in a Tore Supra discharge.The new adapted reconstruction scheme improved the description of the density profile inside the hollow region and also along 10 cm after it.

关 键 词：FM-CW reflectometry profile reconstruction reflectometry density profile hollow profile blind area 

分 类 号：O572.212[理学—粒子物理与原子核物理]