(IT/P1-23) Progress in Diagnostic ITER-relevant Technologies at JET

A. Murari1), E. de la Luna2), J. Brzozowski3), T. Edlington4), M. Angelone5), I. Bolshakova6), G. Ericcson7), G. Gorini8), R. Holyaka9), J. Kaellne7), V. Kiptily4), F. LeGuern9), M. Pillon5), M. Rubel3), M. Santala10), M. Tardocchi8), JET-EFDA Contributors11)
1) Consorzio RFX Associazione ENEA EURATOM per la Fusione, Padova, Italy
2) Asociación EURATOM-CIEMAT para Fusión, CIEMAT, Madrid, Spain
3) Alfvén Laboratory, KTH, EURATOM-VR Association, Sweden
4) EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, UK
5) Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, C.P. 65, I-00044 Frascati, Italy
6) Magnetic Sensor Laboratory (LPNU); 1 Kotliarevsky Str, Lviv, 79013, UKRAINE
7) INF, Uppsala University, EURATOM-VR Association, Uppsala, Sweden
8) Istituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan, Italy
9) Association EURATOM-CEA, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
10) Helsinki University of Technology, Association Euratom Tekes, Espoo, Finland
11) See Appendix of J. Pamela et al., Fusion Energy (2004)(Proc. 20th IAEA Int. Conf. Vilamoura 2004)

Abstract.  The driving elements in JET diagnostic developments during the last campaigns were the operation in tritium (TTE) and the project of the new ITER like RF antenna. These aspects of JET activity promoted a lot of ITER relevant developments in the field of measurements for the fusion products. Neutron spectrometry was upgraded with the implementation of: (i) a Time of Flight neutron spectrometer, (ii) an upgraded Magnetic Proton Recoil spectrometer, with new scintillator solution to measure also the 2.45 MeV neutrons; (iii) compact NE213 liquid scintillators and diamond detectors. The neutron cameras are also being upgraded with fully digital electronics to improve the potential of this system. New data communication technologies will also allow testing feedback schemes based on the neutron emission for burn control applications. Detection techniques for all the various phases of fast particle life, from the first slowing down to the thermalisation and losses, were implemented and tested. The other major area of investigation at JET on the route to ITER is the one of plasma wall interactions. To assess the problems linked with the erosion and redeposition, a series of innovative detectors potentially applicable to ITER, like the rotating collector, was installed. Significant progress in understanding the dependence of the redeposition on the temperature is expected from the new cooled and heated quartz microbalances. Improved information about power loads on the first wall is derived from a new infrared wide angle camera. The installation of an ITER-like Be wall and a new divertor will result in qualitatively different spectroscopic needs. A significant upgrade of spectroscopic diagnostics, from the visible to X-rays, is ongoing to cope with the future metallic wall. Another important drive for diagnostic upgrades is the need of improved profile determination of several kinetic quantities. A better diagnosis of the electron fluid is obtained with: i) an improvement of the ECE radiometer, to increase its resolution and operational space up to 4 T; ii) the implementation of an innovative sweeping reflectometer, with electronic delay to compensate for the long waveguides; iii) upgrades of the Thomson Scattering diagnostics based on the LIDAR method, to hopefully reach spatial resolutions very close to ITER requirements.

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