The present invention includes the use of N-isomers as a source of energy and of neutrons, and the use of K-isomers as a source of energy when associated with a source of neutrons. Although there is strong indirect evidence for the existence of shape isomers in nuclei lighter than actinides, super-deformed (SD) isomeric states have not yet been directly observed. However, rotational bands from such SD states have been observed through .gamma.-ray transitions within high-energy rotational states of this band, as populated by HI reactions. The lifetimes for the shape isomers are likely to be small, but may be increased by effects like the odd-even effects already observed for fission isomers. By contrast, K-isomers have been observed and investigated. If N-isomers are found with the required properties (especially with sufficiently long lifetimes) and produced in sufficient quantities, portable neutron sources more intense than existing neutron sources could be obtained. Neutrons from these sources could also be used to produce energy by using a variety of neutron-induced reactions in selected materials added to the N-isomers, such as K-isomers, which release energy after interacting with neutrons.