Inboard and outboard electron temperature profile measurements in JET using ECE diagnostics

Abstract

In this paper a novel use of the heterodyne radiometer in JET is presented. The operation of the diagnostic has been extended to allow simultaneously measurement of the pedestal temperature profile at the inboard and outboard midplane with high spatial and temporal resolution. Access to the inboard midplane region is obtained by measuring ordinary mode electron cyclotron emission (ECE) (no harmonic overlap) using an antenna located on the low-field side of the torus. To assess the potential of the ECE temperature measurements in the inboard pedestal region, a detailed analysis of ECE spectrum will be discussed. The measured electron temperature profiles are presented, including a discussion of the main uncertainties in the analysis. The comparison of inboard and outboard temperature pedestal profiles in a variety of H-mode plasmas shows a reasonable agreement in both shape and magnitude.