By Geoff Brumfiel

In an effort to put the world's largest scientific experiment back on track after delays and cost overruns, Europe is shaking up the agency overseeing its portion of the multinational ITER reactor.

On February 16, Frank Briscoe, a British fusion scientist, will take the reins as interim director of Fusion for Energy (F4E), the agency in Barcelona, Spain, that manages Europe's ITER contribution--the largest of any partner's. Briscoe replaces Didier Gambier, a French physicist who joined the F4E as director when it formed in 2007. Gambier was originally appointed for a five-year term.

The European Union (EU) is also formulating a plan to complete construction on the multibillion-dollar machine in 2019, a year after currently scheduled, Nature has learned.

ITER aims to prove the viability of fusion power by using superconducting magnets to squeeze a plasma of heavy hydrogen isotopes to temperatures above 150 milliondegrees Celsius. When full-scale experiments begin in 2026, the machine should produce ten times the power it consumes.

Europe will supply some 45 percent of the construction costs for the reactor, including the buildings that will house it in St-Paul-lès-Durance, France. The F4E was created in part to hand out billions of euros in construction contracts. In 2009, it awarded 86 contracts, but major works such as building excavations slated for last autumn have yet to begin, and contracts for crucial elements such as the massive vacuum vessel are not yet signed. Gambier told Nature in October that the delays occurred because ITER's overall design has not been finalized.

But sources say that the European Commission was unhappy with the F4E's performance and with Gambier's leadership. In a December meeting of the European Competitiveness Council, research commissioner Janez Potonik stressed the need for better costing, scheduling and management of ITER.

Catherine Ray, a spokeswoman for the European Commission in Brussels, declined to comment on the circumstances behind Gambier's leaving. So did Gambier, who will take up a new position with the commission. Aris Apollonatos, a spokesperson for the F4E, called the departure a "personal choice."

Briscoe is well known in the global fusion community. From 1996 to 2008 he managed the Culham Science Centre in Abingdon, UK, home to the Joint European Torus, Europe's main fusion experiment. In 2008, he led an independent review of the cost and design of ITER. "He is a very practical, sensible, solid guy," says Robert Goldston, a physicist at Princeton Plasma Physics Laboratory in Princeton, New Jersey.

"We trust that the new team in the F4E will implement the necessary changes to allow the EU to respect its commitments," says Ray.

Europe has faced increasing criticism from ITER's six other international partners: Japan, South Korea, Russia, India, China and the United States. A budget proposed last week by U.S. President Barack Obama would slash America's funding for ITER in 2011 by 40 percent, to US$80 million; it cited "the slow rate of progress by the [ITER Organization] and some Members' Domestic Agencies." And on February 2, Evgeny Velikhov, a Russian fusion researcher and head of ITER's council, called Europe a "weak link." "Unfortunately, their organizational structure is very poor," he told Russian President Vladimir Putin in an interview that appeared on a Russian government Web site.

Finishing ITER in 2019, a goal that the F4E is now working towards with industrial contractors, would involve risks such as producing components in parallel, but scientists think that those risks can be managed. "There should be no doubt that Europe is trying hard to get ITER ready in the shortest time that is realistic," says one senior European scientist. The new schedule will be presented to other ITER partners at a meeting on February 23-24 in Paris.