A team from the Culham Centre for Fusion Energy (CCFE) has spent the last two years assembling SNIF, a device for studying cheaper materials to use with tokamak reactors, in a project the programme leader called a ‘scrapyard challenge’.
SNIF stands for Small Negative Ion Facility, was built from parts of other old machines ('scrapyard') but is also meant to find more economic, better ways to produce neutral beam ions for ITER.
ITER's neutral beam system will consist of two heating neutral beams and a diagnostic neutral beam that will both be based on negative ion source technology. The heating beams inject high-energy (1-2 MeV) D/H beams, that originate from neutralized D-/H- negative ion beams. The standard and most efficient solution up till now, to produce high negative-ion current uses Caesium injection and deposition inside the negative ion source, to enhance negative ion surface-production mechanisms.
The CCFE team will now test several ways of producing the particle beams, and study alternatives to the highly reactive Caesium currently used. SNIF has been operational since June 2012.