It is the long-term goal of the thermonuclear fusion reactor ITER to heat plasma to temperatures that allow for the ignition of the nuclear fusion process, and to harvest the energy set free in this process.
One method to heat the plasma to the required temperatures is to inject a 1 MeV 50 A hydrogen beam into the torus of the reactor. This hydrogen beam is generated by DC acceleration within a complex beam source. MITICA, a beam test facility comprising such a beam source and other components necessary to qualify and measure the beam parameters is under construction at RFX laboratory in Padua, Italy. The MITICA beam test facility is a 1:1 test bed for the future ITER heating system. Upon successful demonstration of the feasibility at MITICA, one or two such beam source heating systems will be manufactured for ITER.
The French company Alsyom recently won the manufacturing contract of the MITICA beam source and has now subcontracted RI Research Instruments for the production of 28 ‘grids’, key components of the beam source. RI has produced similar grids already for SPIDER, another plasma test source for ITER, and is currently finalizing the production of similar grids for the ITER diagnostic neutral beam source. The grids are manufactured by milling from special copper plates with cooling channels closed by electrodeposition of copper. One of the biggest challenges is the final milling of the complex geometry of the grids and meeting the extremely sophisticated requirements regarding flatness and positioning.
RI and Alsyom have a history of successful and trusting cooperation on technically challenging projects. Together, we already produced the ITER pre-production cryopump for F4E as consortium partners. At RI, we are looking forward to continuing this collaboration with Alsyom on the MITICA beam source production.