What is a dirty bomb, and how dangerous is it?
There's growing speculation about ISIS's nuclear ambitions, so how dangerous would a dirty bomb be if one fell into terrorist hands?
Rob Downes is MacArthur Fellow in Nuclear Security working at the Centre for Science and Security Studies, King's College London.
Trained as a mathematician, he received his PhD in mathematics from UCL where he studied the interplay between geometry and spectral theory with applications to physical systems and gravitation. He also holds an MSci in Mathematics with Theoretical Physics from UCL.
His research interests include nuclear security, CBRN terrorism, and complex systems and mathematical modelling.