**Fusion adopter** Debbie Callahan is chief strategy officer at Focused Energy. (Courtesy: Focused Energy) With the world’s energy demands increasing, and our impact on the climate becoming ever clearer, the search is on for greener, cleaner energy production. That’s why research into fusion energy is undergoing something of a renaissance. Construction of the International Thermonuclear Experimental Reactor (ITER) in France – the world’s largest fusion experiment – is currently under way, while there are numerous other large-scale facilities and academic research projects too. There has also been a rise in the number of smaller commercial companies joining the race. One person at the forefront of fusion research is Debbie Callahan – a plasma physicist who spent 35 years working at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in the US.…