Hafnium controversy
The hafnium controversy is a debate over the possibility of 'triggering' rapid energy releases, via gamma ray emission, from a nuclear isomer of hafnium, Hf. The energy release is potentially 5 orders of magnitude (100,000 times) more energetic than a chemical reaction, but 2 orders of magnitude less than a nuclear fission reaction. In 1998, a group led by Carl Collins of the University of Texas at Dallas reported having successfully initiated such a trigger. Signal-to-noise ratios were small in those first experiments, and to date no other group has been able to duplicate these results . Peter Zimmerman described claims of weaponization potential as having been based on "very bad science". Background. Hf is a particularly attractive candidate for induced gamma emission (IGE) experiments, because of its high density of stored energy, 2.5 MeV per nucleus, and long 31-year half life for storing that energy. If radiation from some agent could "trigger" a release of that stored energy, the resulting cascade of gamma photons would have the best chance of finding a pair of excited states with the inverted lifetimes needed for stimulated emission. While induced emission adds only power to a radiation field, stimulated  emission adds coherence. A proposal to test the efficacy for "triggering" Hf was approved by a NATO-Advanced Research Workshop (NATO-ARW) held in Predeal in 1995. Although the proposal was to use incident protons to bombard the target, α-particles were available when the first experiment was scheduled. It was done by a French, Russian, Romanian and American team. Results were said to be extraordinary, but the results were not published. Nevertheless, Hf was implied to be of special importance to potential applications of IGE. A controversy quickly erupted. References. "Also note:"