Author/Authors :
Cupido، نويسنده , , Maria L. and Luna D’Amicis، نويسنده , , E. de la and Antonucci، نويسنده , , C. and Guigon، نويسنده , , A. and van Amerongen، نويسنده , , F.J. and Bongers، نويسنده , , W.A. and Donné، نويسنده , , A.J.H. and Graswinckel، نويسنده , , M.F. and Bruschi، نويسنده , , A. and Cirant، نويسنده , , S. and Simonetto، نويسنده , , A. and Sozzi، نويسنده , , C. and Wagner، نويسنده , , D. and Manso، نويسنده , , E. and Meneses، نويسنده , , L. and Silva، نويسنده , , F. and Varela، نويسنده , , P. and Balshaw، نويسنده , , N. and Chareau، نويسنده , , J.M. and Conway، نويسنده , , G. and Fessey، نويسنده , , J. and Hanks، نويسنده , , S. and Pearce، نويسنده , , R. L. Ricardo L. Viana، نويسنده , , V. and Sands، نويسنده , , D. and Starky، نويسنده , , D. and Tisconia، نويسنده , , T.، نويسنده ,
Abstract :
Millimeter-wave diagnostics at JET, mainly reflectometry, are employing state of art electronics, but are limited in performance by the existing waveguides and antenna system that are inadequate and obsolete. The use of long run waveguides with high losses and non-optimized antennas (in some cases, not pointing to relevant plasma positions) lead to difficult measurement conditions for reflectometry.
w access system presented in this article has been designed to improve the performance of reflectometry measurements and enable the installation of antennas for oblique viewing ECE. These two new antennae will allow the ECE radiation to be collected at different angles with respect to the magnetic field. This set-up, known as oblique ECE [1], is expected to be extremely useful in improving the interpretation of ECE temperature measurements in all fusion experiments with significant additional heating. For reflectometry, there is an urgent need to improve the edge density measurements as both the lithium beam and Thomson scattering exhibit limitations of resolution at lower densities.
oject proposal states that the expected improvement in reflectometry S/N ratio is 30 dB. If realized, this will allow broad band reflectometry, for the measurement of the electron density profile, for the first time in JET.
