  Long-lived excited states of atomic nuclei can act as energy traps. These
states, known as nuclear isomers, can store a large amount of energy over long
periods of time, with a very high energy-to-mass ratio. Under natural
conditions, the trapped energy is only slowly released, limited by the long
isomer lifetimes. Dynamical external control of nuclear state population has
proven so far very challenging, despite ground-breaking incentives for a clean
and efficient energy storage solution. Here, we describe a protocol to achieve
the external control of the isomeric nuclear decay by using electrons whose
wavefunction has been especially designed and reshaped on demand. Recombination
of these electrons into the atomic shell around the isomer can lead to the
controlled release of the stored nuclear energy. On the example of $^{93m}$Mo,
we show that the use of tailored electron vortex beams increases the depletion
by four orders of magnitude compared to the spontaneous nuclear decay of the
isomer. Furthermore, specific orbitals can sustain an enhancement of the
recombination cross section for vortex electron beams by as much as six orders
of magnitude, providing a handle for manipulating the capture mechanism. These
findings open new prospects for controlling the interplay between atomic and
nuclear degrees of freedom, with potential energy-related and high-energy
radiation sources applications.
