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SHAD ( Sub-Harmonic Arc Detector) Project for the ICRH TS Antennae and JET ILA (ITER Like Antenna). G.BERGER-BY with the TS and JET ICRH teams. Tore Supra experience in SHAD and results CEA project: SHAD for JET ILA Expected results on ILA in JET Required developments in progress.
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SHAD ( Sub-Harmonic Arc Detector) Project for the ICRH TS Antennae and JET ILA (ITER Like Antenna) G.BERGER-BY with the TS and JET ICRH teams • Tore Supra experience in SHAD and results • CEA project: SHAD for JET ILA • Expected results on ILA in JET • Required developments in progress
Tore Supra experience and results with the ICRH team • TS work program in 1999 with IPP Garching • 4 improvements to the Garching system have been developed on the first prototype in 2001 - Auto-test system (10MHz) - Industrial filters (JET 5/20MHz) 80 dB rejection - Logarithmic detection to increase the adjustment possibilities - Optic fiber for the connection to the trip system (fast, immunity) • Industrial manufacturing of 3 racks in 2002 in France • Used on the TS antennae since 2002 without modification and without failure • Since 2005 the 3 TS antennae are protected with SHAD in redundancy • Used with very large success on the TS ITER Like antenna on test bed commissioning and on 2007 plasma campaign • Experience of using 4 safety systems (Generator Vr/Vf, antenna Vr/Vf, SHAD, optic systems for the TS ILA is that SHAD has been very useful and has been high sensibility for arcs detection
ITER-Like Antenna Prototype : Sub-Harmonic Arc Detection SHAD Arc detection system based on sub-harmonic detection (installed on the JET-EP antenna) Arc detection signal (10ms) Reaction time <10s The classical safety system based VSWR measurement was also used as a fall-back system (triggering only a few times in operation) Thanks to K.Vulliez (JET talk on January 23th 2008)
2) CEA project: SHAD for JET ILA • 2 racks with 2 independent channels (4 lines to supply the ILA) • Same CEA principle with industrial manufacturing in France (2006 4th Quarter) • Delivery to JET in January 2007 with all the documentation • Tests expected in 2007 on the test bed, but delayed because technical problems during the 4th strap commissioning (just some preliminary tests have been made) • Full commissioning on the ILA expected in the first Half-yearly 2008 • phase 1: Multipactor and vacuum (April) • phase 2: Plasmas in L mode (May) • phase 3: Plasmas with ELMs in H mode (June)
3) Expectedresults on ILA in JET • Noise measurements with spectrum analyser • Fast acquisition (200 kHz) and fast triggers • Spectrum analysis with fast oscilloscope (TS=5GS/s) and FFT calculation • Full collaboration between TS, ASDEX and JET will be useful • Comparison VSWR, with 2 different systems SHAD, SMAD (Sensibility, delay, immunity) • Sensitivity of the SHAD in ELMs plasmas (no tested on TS) • This technique could be used on ITER ? • How to manage different systems in order to increase safety without decrease the availability? 4) Required developments in progress