Sir

In your News story “Fusion cash shortfall leaves JET grounded” (Nature 424, 4; 2003), you cite Alexander Bradshaw's view that the “sensible” option for the European Union (EU) fusion programme is to close the Joint European Torus (JET), implying that it is a luxury, low-priority item.

This could not be further from the truth. JET is the most relevant device to ITER, the planned international magnetic fusion reactor, for addressing questions of how scenarios, performance limits, heat loads and stresses extrapolate with device size. As a scientist working on JET, I must point out that it is also developing key techniques that would otherwise have to await much more expensive research programmes in ITER. Examples include the development of tritium and remote-handling technologies, ion cyclotron and lower hybrid resonant heating techniques, D–T fusion capability and exploration of effects of 'fast' particles (which can only be confined in a large device such as JET) in heating and changing the stability of the plasma. Thus JET is exploring the 'new' physics of ITER, and developing techniques and understanding to speed ITER's research programme.

In recent years JET has been redeveloped as a model of European collaboration, enabling even small scientific associations to have leading roles in key fields for ITER. Without a centrally funded EU facility, the EU fusion programme would have no coherence. We should be following the example of particle physics, pooling resources at every level in the operation of major shared facilities that most directly address the development of the field.

Closing JET may seem the easy option, giving each country the security of having its own individual programme. A far more sensible, though challenging, option is for directors to make the case for increased fusion funding, a restructured and more centralized European programme, and to centre national resources and programmes on a few pan-European facilities.

JET remains at the forefront of the world fusion programme. With the many upgrades and new systems coming online over the next 18 months, and the vigour injected by its collaborative framework, it has one of the most diverse, dynamic and intensive ITER-relevant programmes in the world. It should be the last part of the EU programme to be closed down.