Search

The tokamak JT-60SA is presently under construction in Naka (Japan) as a joint collaboration between Europe and Japan on the field of nuclear fusion research, in the framework of the Broader Approach Agreement. According to the international agreement, the different systems composing JT-60SA are supplied by European and Japanese institutions. In particular the four Switching Network Units (SNU) for the Central Solenoid (CS) of JT-60SA have been procured by ENEA. The design, manufacturing and factory test activities have been completed in 2016, and after the delivery in Naka the SNU have been installed and successfully commissioned in 2017. After an overview on the main technical characteristics of the SNU and the key aspects of their design, this paper describes the activities performed on-site, highlighting the results obtained during the final acceptance tests and comparing them with the design simulation and the factory test results.

Questa pubblicazione rappresenta il “conceptual design report” per una sorgente a radiofrequenza di tipo CARM (Cyclotron auto resonance maser) operante a 250 GHz e progettata per attività di ricerca sul plasma. Lo studio è finalizzato alla pianificazione della costruzione di un dispositivo di tipo CARM nel Centro ENEA di Frascati, nell’ambito di ricerche concernenti la fusione nucleare. Le attività contemplate nel progetto raccolgono assieme differenti competenze tradizionalmente presenti all’interno dell’ENEA e, oltre la già citata fusione, riguardano la scienza e tecnologia degli acceleratori di particelle, la gestione e il trasporto dei fasci di particelle cariche, la superconduttività. Il documento prende in considerazione i vari particolari del progetto ed è diviso in due parti. La prima include la descrizione generale dell’intero sistema, tra l’altro presentando le ragioni a supporto della scelta del CARM, i presupposti teorici, le ragioni della la scelta dei parametri di operazione e le prestazioni attese dalla sorgente stessa. Nella seconda parte del testo sono riportati i dettagli costruttivi e ogni aspetto è adeguatamente descritto negli annessi tecnici: il progetto del catodo, la formazione e il trasporto del fascio di elettroni; le caratteristiche della alimentazione elettrica e della linea formatrice di impulso; il magnete superconduttore e le caratteristiche della cavità del CARM; lo sviluppo dei codici di calcolo per l’analisi delle prestazioni RF della sorgente., We present the conceptual design for a Cyclotron Auto Resonance Maser source, operating at 250 GHz and conceived for Plasma Fusion research ac- tivities. The study discussed here is aimed at planning the construction of such a device at the ENEA Frascati Center, within the framework of the researches pertaining to the Fusion department. This foreseen activity gather together different skills traditionally present in the Agency and including Fusion, ac- celerator technology, beam handling and transport, superconductivity. . . The report covers the different details of the project and is devided in two parts. The first contains a general description of the entire system, furthermore it describes the motivations underlying the choice of the de- vice, the relevant theoretical foundations, the reasons for the choice of the operating parameters and the expected performances of the source. In the second part the project details are reported and each constituting item is properly described in the technical annexes. We discuss indeed the cathode design and the electron beam shaping and transport, we report on the power supply and electrical pulse forming line, on the Superconduct- ing magnet and CARM cavity characteristics. Finally we discuss the code development effort for the analysis of the radiation output performances.

The Divertor Tokamak Test (DTT) facility, construction starting at Frascati, Italy, is designed to test different solutions for divertor in view of DEMO. A preliminary analysis of the error fields (EFs) assumed a simplified model of rigid and independent displacements and rotations. A methodology based on the first order truncated Taylor expansion has been applied, linking the displacement parameters and the EFs within the required ac-curacies. A system of in-vessel copper coils has been designed to counteract EFs and the ampere-turns necessary to force them back within the request limits has been calculated. Here, the details of the analysis have been provided.

The paper reports the results of the test and modelling activities carried out on large commercial supercapacitor cells at high current. Four commercials cells, with rated capacitance of 3000 F and rated voltage of 2.7 V, are considered. All cells are submitted to consecutive charge/discharge cycles at constant current. A test current in the range 80-130 A is used, which is comparable with the maximum operating current (up to 150 A) that the cells can reach in practical operations. A circuit model of the cells, able to reproduce the most relevant dynamic behavior, with a good compromise between accuracy, simplicity and robustness of the model's parameters, is also developed and validated against the experimental data. It is shown that all the investigated commercial cells are characterized by similar phenomena and comply with the same circuit model. Moreover, it is shown that the circuit parameters of the cells are in the same range and are weakly dependent on the test current. The obtained circuit parameters are accurately reported for all the cells and made fully accessible to users.