CNR ExploRA

Articolo in rivista, 2023, ENG, 10.1016/j.fusengdes.2023.113590

Lessons learned after three years of SPIDER operation and the first MITICA integrated tests

Marcuzzi D.; Toigo V.; Boldrin M.; Chitarin G.; Dal Bello S.; Grando L.; Luchetta A.; Pasqualotto R.; Pavei M.; Serianni G.; Zanotto L.; Agnello R.; Agostinetti P.; Agostini M.; Aprile D.; Barbisan M.; Battistella M.; Berton G.; Bigi M.; Brombin M.; Candela V.; Candeloro V.; Canton A.; Casagrande R.; Cavallini C.; Cavazzana R.; Cordaro L.; Cruz N.; Dalla Palma M.; Dan M.; De Lorenzi A.; Delogu R.; De Muri M.; De Nardi M.; Denizeau S.; Fadone M.; Fellin F.; Ferro A.; Gaio E.; Gasparrini C.; Gnesotto F.; Jain P.; La Rosa A.; Lopez-Bruna D.; Lorenzini R.; Maistrello A.; Manduchi G.; Manfrin S.; Marconato N.; Mario I.; Martini G.; Milazzo R.; Patton T.; Peruzzo S.; Pilan N.; Pimazzoni A.; Poggi C.; Pomaro N.; Pouradier-Duteil B.; Recchia M.; Rigoni-Garola A.; Rizzetto D.; Rizzolo A.; Santoro F.; Sartori E.; Segalini B.; Shepherd A.; Siragusa M.; Sonato P.; Sottocornola A.; Spada E.; Spagnolo S.; Spolaore M.; Taliercio C.; Tinti P.; Tomsic P.; Trevisan L.; Ugoletti M.; Valente M.; Valisa M.; Veronese F.; Vignando M.; Zaccaria P.; Zagorski R.; Zaniol B.; Zaupa M.; Zuin M.; Cavenago M.; Boilson D.; Rotti C.; Decamps H.; Geli F.; Sharma A.; Veltri P.; Zacks J.; Simon M.; Paolucci F.; Garbuglia A.; Gutierrez D.; Masiello A.; Mico G.; Labate C.; Readman P.; Bragulat E.; Bailly-Maitre L.; Gomez G.; Kouzmenko G.; Albajar F.; Kashiwagi M.; Tobari H.; Kojima A.; Murayama M.; Hatakeyama S.; Oshita E.; Maejima T.; Shibata N.; Yamashita Y.; Watanabe K.; Singh N.P.; Singh M.J.; Dhola H.; Fantz U.; Heinemann B.; Wimmer C.; Wunderlich D.; Tsumori K.; Croci G.; Gorini G.; Muraro A.; Rebai M.; Tardocchi M.; Giacomelli L.; Rigamonti D.; Taccogna F.; Bruno D.; Rutigliano M.; Longo S.; Deambrosis S.; Miorin E.; Montagner F.; Tonti A.; Panin F.

Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Padova, Italy; CNR ISTP - Istituto per la Scienza e Tecnologia dei Plasmi, Sedi di Milano, Padova e Bari, Italy; Department of Management and Engineering, Università degli Studi di Padova, Vicenza, Italy; Ecole Polytechnique Federale de Lausanne (EPFL) - Swiss Plasma Center (SPC), Lausanne, Switzerland; INFN-Laboratori Nazionali di Legnaro (LNL), PD, Italy e Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, Portugal; Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria; Laboratorio Nacional de Fusion, CIEMAT, Madrid, Spain; CCFE, Culham Science Centre, Abingdon, Oxon, UK; Faculty of Mechanical Engineering, University of Ljubljana, Slovenia; National Centre for Nuclear Research (NCBJ), Otwock, Poland; ITER Organization, St Paul-lez-Durance, France; Fusion for Energy, Barcelona, Spain; National Institutes for Quantum and Radiological Science and Technology (QST), Naka, Ibaraki-ken, Japan; ITER-India, Institute for Plasma Research, Gandhinagar, Gujarat, India; IPP, Max-Planck-Institut fur Plasmaphysik, Garching bei Munchen, Germany; LAPLACE, CNRS, Universite de Toulouse, France; National Institute for Fusion Science, Toki, Gifu, Japan; Dipartimento di Fisica G. Occhialini, Università di Milano-Bicocca, Milano, Italy; CNR ICMATE, National Research Council of Italy, Institute of Condensed Matter Chemistry and Technologies for Energy, Padova, Italy; INAIL-DIT, Roma, Italy; INAIL-UOT, Padova, Italy.

ITER envisages the use of two heating neutral beam injectors plus an optional one as part of the auxiliary heating and current drive system, to reach the desired performances during its various phases of operation. The 16.5 MW expected neutral beam power per injector is several notches higher than worldwide existing facilities. In order to enable such development, a Neutral Beam Test Facility (NBTF) was established at Consorzio RFX, exploiting the synergy of two test beds, called SPIDER and MITICA. SPIDER is dedicated developing and characterizing large efficient negative ion sources at relevant parameters in ITER-like conditions: source and accelerator located in the same vacuum where the beam propagates, immunity to electromagnetic interferences of multiple radio-frequency (RF) antennas, avoidance of RF-induced discharges on the outside of the source. Three years of experiments on SPIDER have addressed to the necessary design modifications to enable full performances. The source is presently under a long shut-down phase to incorporate learnings from the experimental campaign, in particular events/issues occurred during operation, which led to the identification of improvement opportunities/necessities (e.g. RF discharges, local burns, water leaks, other damages, configuration/design upgrades to maximize chances/margin to quest target parameters). Parallelly, developments on MITICA, the full-scale prototype of the ITER Neutral Beam Injector (NBI) featuring a 1 MV accelerator and ion neutralization, are underway including manufacturing of the beam source, accelerator and the beam line components, while power supplies and auxiliary plants, already installed, are under final testing and commissioning. Integration, commissioning and tests of the 1 MV power supplies are essential for this first-of-kind system, unparalleled both in research and industry field. 1.2 MV dc insulating tests of high voltage components were successfully completed. The integrated test to confirm 1 MV output by combining invertor systems, DC generators and transmission lines extracted errors/accidents in some components. To realize a concrete system for ITER, said events have been addressed and solutions for the repair and the improvement of the system were developed. Hence, NBTF is emerging as a necessary facility, due to the large gap with existing injectors, effectively dedicated to identify issues and find solutions to enable successful ITER NBI operations in a time bound fashion. The lessons learned during the implementation on NBTF and future perspectives are here discussed.

Fusion engineering and design (Print) 191 , pp. 113590-1–113590-11