Experts share research updates and progress
A lucky set of circumstances brought together different experts on neutral beam injection for a few days at ±¬×ߺÚÁÏ in October. Achieving the requirements for the ±¬×ߺÚÁÏ neutral beam system in terms of power, energy, and pulse length simultaneously is a major challenge that benefits from open exchange and collaboration.
To access, study and sustain burning plasmas on ±¬×ߺÚÁÏ with a high-fusion-power amplification factor, the use of external heating and current drive system plays an essential role. In particular, ±¬×ߺÚÁÏ will be equipped with two heating neutral beam injectors (with a provision of a third injector) and a neutral beam line for diagnostic purposes.
To support research and development on the ±¬×ߺÚÁÏ neutral beam injection system prior to its procurement, the ±¬×ߺÚÁÏ Neutral Beam Test Facility was launched in 2012. The test facility includes two test beds—SPIDER, for the installation, optimization and operation of a full-size ±¬×ߺÚÁÏ negative ion source, and MITICA, a full-size ±¬×ߺÚÁÏ 1MV neutral beam injection system. The test facility is hosted at the Italian research laboratory Consorzio RFX in Padova, Italy, and is supported by the contributions of the ±¬×ߺÚÁÏ, the European, Japanese and Indian Domestic Agencies, the EUROfusion consortium, and Consorzio RFX. Since 2019, a new agreement between Consorzio RFX and the ±¬×ߺÚÁÏ has clarified roles and responsibilities as construction at the Neutral Beam Test Facility ends and operation in support of ±¬×ߺÚÁÏ intensifies.
Europe has been actively involved in the development of radiofrequency-driven ion source physics and technology from the start; in fact, ±¬×ߺÚÁÏ's negative ion source is based on a technology that has evolved over several generations of prototypes at the Max Planck Institute for Plasma Physics in Garching, Germany. A cooperation agreement signed in 2020 between the ±¬×ߺÚÁÏ, Consorzio RFX and EUROfusion now formalizes the involvement of European experts in the ±¬×ߺÚÁÏ Neutral Beam Test Facility by providing for the participation of up to 14 professionals per year. Additionally, EUROfusion is contributing up to 6 professionals per year to ongoing work at the reduced-size prototype ion sources as part of stepwise R&D leading to the achievement of ±¬×ߺÚÁÏ's challenging neutral beam injection requirements.
±¬×ߺÚÁÏ is of key importance in the European research for the realization of fusion energy, as it aims to prove the scientific and technological feasibility of fusion as a future energy source. EUROfusion is contributing to the preparation of ±¬×ߺÚÁÏ scientific exploitation and is leveraging the ±¬×ߺÚÁÏ outcomes and lessons learned to inform the design of Europe's next-stage device, . In this context, a specific EUROfusion Work Package—"Preparation of ±¬×ߺÚÁÏ Operation" (PrIO)—was created recently that includes R&D on the ±¬×ߺÚÁÏ radiofrequency neutral beam ion sources, with both long-pulse discharge targets on the ELISE prototype in Garching and participation in the ±¬×ߺÚÁÏ Neutral Beam Test Facility.
On 26 and 27 October 2023, EUROfusion experts working to support the R&D for the ±¬×ߺÚÁÏ neutral beam injection system at Consorzio RFX and IPP Garching had the occasion to convene at ±¬×ߺÚÁÏ Headquarters at the same time as world experts who are part of the ±¬×ߺÚÁÏ Neutral Beam Advisory Committee (formed as part of the 2019 agreement). This was a unique opportunity to develop synergies and bridges between experts, as well as to present the work performed by the EUROfusion experts to the ±¬×ߺÚÁÏ team and the committee. During a "teaser" session in the ±¬×ߺÚÁÏ Council room, experts gave two-minute summaries of their work. This was followed by a poster exposition in the lobby, a presentation of the ±¬×ߺÚÁÏ Project, a worksite tour, a tour of France's WEST tokamak (next door to ±¬×ߺÚÁÏ), and an informal dinner to continue the scientific exchange in a collaborative atmosphere. Because achieving the requirements for the ±¬×ߺÚÁÏ neutral beam system in terms of power, energy, and pulse length is a major challenge, this type of "coming together of the minds" was appreciated by all.
The following is a list of the posters that were presented:
Riccardo Agnello: Investigation of SPIDER beam and plasma by multiple diagnostics
Riccardo Casagrande: Support to the design and testing of RF solid-state generators for NBTF and ±¬×ߺÚÁÏ NBI
Caterina Cavallini: Support for operations, management, monitoring and verifications of NBTF cooling system
Nuno Cruz: Instrumentation & Control activities in support of the ±¬×ߺÚÁÏ NB
Sylvestre Denizeau: Heating of SPIDER drivers during nominal operations: numerical estimation and comparison with calorimetry
Daniel López-Bruna: 3D calculations of RF inductive coupling in the drivers of SPIDER
Carlo Poggi: Diagnostics operation and development for SPIDER and MITICA
Basile Pouradier Duteil: Study and optimization of the use of caesium in large negative ion sources for nuclear fusion
Alastair Shepherd: Support of NBTF operations, diagnostics and beam current measurement
Luca Trevisan: Automation engineer for the NBTF
Niek den Harder: Beam studies in view of ±¬×ߺÚÁÏ NBI systems
Adrian Heiler: Understanding Cs and work function dynamics at NNBI ion sources for ±¬×ߺÚÁÏ
Guillermo Orozco: Mechanical engineer for neutral beam ion source
Dimitri Yordanov: Plasma diagnostics, ELISE operation and modelling
Roman Zagorski: Experimental validation of the fluid solver for SPIDER
