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°ÄÃÅÁùºÏ²Ê¸ßÊÖ Neutral Beam Test Facility

A collaborative effort

25 Sep 2023 - Maria Teresa Orlando, Consorzio RFX
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Engineers and physicists from the Neutral Beam Injection Group at the Max Planck Institute for Plasma Physics together with members of the Neutral Beam Test Facility Team in the experimental hall.

One of °ÄÃÅÁùºÏ²Ê¸ßÊÖ's three external heating systems—neutral beam injection—is being tested in advance at the Neutral Beam Test Facility (NBTF) in Padua, Italy. The state-of-the-art facility represents the culmination of decades of research. 

On 13 September 2023, engineers and physicists from the Neutral Beam Injection Group (°ÄÃÅÁùºÏ²Ê¸ßÊÖ Technology and Diagnostics Division) at the Max Planck Institute for Plasma Physics (IPP) visited the installation as part of a two-day meeting in Padua at Consorzio RFX to discuss progress in collaborative activities for °ÄÃÅÁùºÏ²Ê¸ßÊÖ neutral beam injection. Members of the Neutral Beam Test Facility team exchanged recent experimental results with their IPP colleagues and discussed further plans to be carried out at both institutes. They visited the test facility's experimental hall and its two full-size prototypes—SPIDER (an °ÄÃÅÁùºÏ²Ê¸ßÊÖ-scale negative ion source designed to achieve all ion source requirements) and MITICA (a full-size 1 MV heating neutral beam injector, capable of full acceleration voltage and power).

At IPP two test facilities have been supporting the development of the radio-frequency-driven ion source for °ÄÃÅÁùºÏ²Ê¸ßÊÖ neutral beam injection for many years as part of the European roadmap: BATMAN Upgrade, a prototype ion source, and ELISE, an ion source one half the size of °ÄÃÅÁùºÏ²Ê¸ßÊÖ's.  

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Inside of the MITICA bunker with the vacuum vessel on the right and the last part of the 1MV transmission line in blue. When it enters operation, MITICA will be a 1:1-scale °ÄÃÅÁùºÏ²Ê¸ßÊÖ neutral beam injector, the first to operate at °ÄÃÅÁùºÏ²Ê¸ßÊÖ requirements (up to the full acceleration voltage of 1 MV and full power of 16.5 MW).
At the Neutral Beam Test Facility, hosted by the Italian research laboratory Consorzio RFX, SPIDER started operation in 2018 and is currently completing a full device upgrade, initiated after the first experimental campaigns identified a set of key improvements. This is exactly what the NBTF project is for—testing and exploring physics and technology issues and validating concepts before the neutral beam system is installed on °ÄÃÅÁùºÏ²Ê¸ßÊÖ. 

Although neutral beam injection is routinely used for plasma heating in fusion devices, the size of °ÄÃÅÁùºÏ²Ê¸ßÊÖ imposes enhanced requirements: particle beams have to be much thicker, for example, and individual particles have to be much faster in order to travel far into the core of the plasma. 

Read more about neutral beam injection and the Neutral Beam Test Facility and here.