Previous work has already shown that the techniques proposed by Phoenix can detect defects as small as 4mm x 4mm. The company has now been given the go-ahead to begin the second phase of the project, where the emphasis will be on developing a prototype inspection system. John Turner, special projects manager at Phoenix, explains: “Narrow gap welding processes make for more rapid production with less use of filler metals. However, the coarse grain structure in the weld metal makes it difficult for the ultrasound beam to penetrate and detect defects that may be present.

We have found that low frequency waves and the use of ultrasonic phased array devices in conjunction with more established techniques can help to overcome these problems. Trials so far have been successful in showing up even very small defects and we are now working on refining our techniques. “We are also developing a design for a scanner, and here we have to take a practical engineering approach, since any system will have to work within very tight constraints of space.”

Nuclear fusion relies on fusing atoms together, as opposed to fission, which involves splitting the atom and is the basis of current nuclear energy production. Scientists around the world have been working on fusion programmes since the 1950s and so far a number of fusion machines have been developed which are able to generate increasing amounts of energy. The ITER project addresses the technical challenges involved in making fusion a practical source of energy for the 21st century.