What’s New

Some of the most detailed images ever of a hot plasma inside a tokamak have been captured at MAST, the spherical tokamak device at the Culham Centre for Fusion Energy (CCFE) in the UK.

At 100,000 frames per second, the movies from the MAST device give a vivid illustration of how tokamaks keep fusion fuel trapped in a magnetic cage, with particles moving around magnetic field lines and resembling a large spinning ball of wool.

If only it were that simple; in reality, a magnetically-confined plasma is a highly complex system, and predicting how it behaves is key to making nuclear fusion a viable energy source. In particular, knowing how the hot fuel affects the cold walls of the machine is integral to ensuring that future reactors survive.

Turbulence in the magnetic field throws out wispy bunches of particles—known as filaments—from the plasma in a seemingly random fashion, ejecting fuel which touches the surfaces of the tokamak. Researchers are now working to unravel meaning within this randomness to understand this complex interaction with the machine walls, and videos such as these can give them pointers to what is happening.

Nick Walkden of CCFE's Theory & Modelling Department, who produced the videos, explains: "We believe that filaments are a vital part of the 'exhaust process' within a tokamak—how particles are expelled from the plasma. Seeing the MAST plasma at this unprecedented level of detail enables us to image individual filaments and measure their size, velocity and position within the plasma. It tells us a lot about their physics so we can find out how to predict their motion and, in future experiments, possibly learn to control them."

Read the full article at CCFE. 

Physicist Richard Hawryluk of the Princeton Plasma Physics Laboratory (PPPL) has been named chair of the board of editors of Nuclear Fusion.

Current head of the ITER and Tokamaks Department at PPPL and former Deputy Director-General of Administration at ITER, Hawryluk has been a member of the editorial board at Nuclear Fusion since 2009. In his new role as chair he will provide policy oversight and support to the journal's editor.

From 1991 to 1997 he headed the Tokamak Fusion Test Reactor (TFTR) project, the only magnetic confinement fusion experiment in the US to have operated on a high-power mix of deuterium and tritium. He was also deputy director of PPPL lab from 1997 to 2009, before taking over the running of the ITER and Tokamaks Department.

Less than one year ago, last December, the ITER Organization signed a large supply contract with W. Schulz GmbH in Germany for the procurement of piping materials. The scope covers up to 65 km (1,800 tonnes) of pipes and 43,000 units (250 tonnes) of fittings. 

The first shipment of pipes and fittings under this contract was delivered late October to the ITER worksite. It was the inaugural delivery of a broad ITER Organization-Domestic Agency program for the centralized procurement of piping materials for the component (CCWS), chilled (CHWS), and tokamak cooling water systems, expected to play out over five years.

Thirty-three tonnes of material were delivered, including 450 metres of stainless steel seamless pipes and 350 stainless steel fittings such as tees, elbows and reducers. The material will be stored in ITER's largest warehouse on site until needed for installation.