Gleaming beamline will put the heat into MAST Upgrade

CCFE 17/10/2016

Here’s a glimpse into one of the completed MAST Upgrade Neutral Beam heating systems – and at some exquisite fusion engineering.

The team working on MAST Upgrade’s main plasma heating system, the two neutral beam injectors (NBI), recently passed a major milestone when they completed the installation of equipment into the two NBI vacuum vessels.

Often likened to a high-powered cappuccino machine, the NBIs will inject fast-moving neutral particles into the MAST-U plasma, in much the same way that steam goes into the milk in your coffee to heat it up. This will provide most of the muscle to get the plasma to the target temperatures of around 50 million degrees C for five second pulses during MAST-U experiments.

Following months of preparations – assembling the NBI components, cleaning and vacuum testing the vessels, refurbishing existing parts and carrying out trial fits of the system – the installation of the internal components went very smoothly and only took around a week.

“This is MAST Upgrade’s largest sub-system so we’re glad to have it all ready, and keen to link it up to the tokamak,” says Sanjay Mistry of the MAST-U team. “We’ve had great support from colleagues in the Vacuum Group and Engineering Installation Group, and we’ve worked closely with the NBI operators, who’ve been actively involved in the build.

“We still have work to do on the cooling system, power supplies and control systems – and of course in reconnecting the NBI vessels to MAST Upgrade itself. But we’re in good shape to have both beamlines finished by the end of this year.”