Speakers
Description
Electrical and magnetic measurements play a fundamental role in magnetically confined fusion research, including devices such as RFX-mod2, DTT, and ITER, as well as in plasma-based systems and accelerator facilities such as SPIDER and MITICA. The magnetic and electrical diagnostics serve a dual role: they provide the real-time signals necessary for plasma control and machine protection, while simultaneously forming the primary dataset for post-shot physics analysis and most import for plasma equilibrium reconstruction, which is fundamental for all subsequent analysis.
Modern fusion devices rely on highly sophisticated plasma control architectures. A large number of coordinated controllers must operate simultaneously to shape, stabilize, and sustain the desired plasma scenario, in accordance with both experimental objectives and operational constraints. The effectiveness of these control strategies depends directly on the quality, accuracy, bandwidth, and reliability of real-time diagnostic measurements. Fast and reliable measurements are indispensable to detect off-normal events, mitigate instabilities, and safeguard both the plasma-facing components and the overall machine.
Funded through the PNRR (Piano Nazionale di Ripresa e Resilienza - National Recovery and Resilience Plan), NEFERTARI (New Equipment for Fusion Experimental Research and Technological Advancements with RFX Infrastructure) is a coordinated €18M investment program aimed at modernizing the Italian fusion research infrastructure centered on RFX-mod2. Representing a structural investment in scientific capacity, technological innovation, and human capital, NEFERTARI’s goal is to enhance diagnostic capabilities and reinforce a national network of advanced fusion laboratories. The program is organized into nine dedicated Work Packages (WPs) addressing complementary technological areas.
Work Package 2 (WP2), with an allocated budget of €2.5M for hardware and personnel, plays a central role in enhancing the experimental performance of RFX-mod2. It is dedicated to the development, installation, and integration of an advanced system for electromagnetic measurements and real-time plasma feedback control, addressing one of the key challenges in magnetically confined fusion devices: the stabilization and control of magnetohydrodynamic (MHD) instabilities. The WP's achievements are structured across three main lines:
1. Hardware Design and Signal Acquisition
The new front-end boards for the conditioning and acquisition of the signal from 1424 magnetic sensors to control the plasma and protect the machine has been designed, procured and tested. The system is based on flexible ADC architecture, providing a purely numerical integration of signals. The system simultaneously provides high-resolution DAQ for physical studies and a limited bandwidth low latency real time data stream for plasma control system. The new in air multi pair shielded cables to connect the in-vessel magnetic sensors to the acquisition boards have been procured. Additionally, the multimedia and IT materials for the new Control Room have been purchased. To ensure precise execution, a specific service contract with TF_Automazioni provided qualified personnel to support Consorzio RFX technicians during the assembly of the machine's electromagnetic sensors.
2. Machine Protection and Control Algorithms
Leveraging the CREATE-L model, a control-oriented electromagnetic model of RFX-mod2 was developed. This facilitated the creation of advanced, model-based algorithms for magnetic control and fault detection, combining physics-informed and data-driven approaches. These algorithms aim to improve stability control, increase accuracy in magnetic field regulation, and extend the operational envelope of the device. Furthermore, adaptive fault-detection strategies were developed to automatically recognize and classify abnormal conditions in real time, determining optimal corrective actions without requiring manual reconfiguration for different plasma scenarios.
3. In-House EMC Pre-Compliance Laboratory
A pre-compliance Electromagnetic Compatibility (EMC) laboratory, featuring a fully instrumented anechoic chamber, has been realized. Compliant with EMC testing standards, this facility enables radiated and conducted emission measurements, magnetic sensor calibration, and material characterization under harsh environmental conditions (strong RF/microwave, magnetic, and electrical fields). This in-house capability is a strategic asset for the rapid verification and iterative design of diagnostic electronics. By proactively assessing immunity to the severe electromagnetic noise inherent in fusion environments, the lab minimizes integration delays, reduces operational downtime, and prevents critical failures once systems are installed on the device.