About a half century ago it was discovered that an enormous magnetic field (several thousand tesla) acts at the nucleus of an ion swiftly traversing a magnetized ferromagnetic medium. This so-called transient magnetic field has been used to measure the magnetic moments of many nuclear quantum states with lifetimes of the order of picoseconds. Several parametrizations of the transient-field strength in terms of the ion velocity and its atomic number have been used to obtain nuclear moments. However these parametrizations cannot always be relied upon; the example in the figure shows observed transient-field strengths that exceed an often used parametrization by 40%.
The International Atomic Energy Agency has instigated an evaluation of magnetic moment measurements on nuclear states to provide recommended values for the research community. The aim of this project is to review the data, which now stretch back several decades, to re-evaluate the transient-field parametrizations, and seek to put this class of nuclear moment measurements on a consistent footing.
The project will require careful reading of the literature, collation of data, and computation. Although it begins with mining the existing data, we anticipate new discoveries from looking at the big picture, including new insights into the physics of ion-solid interactions, and pre-equilibrium effects associated with ion implantation, along with nuclear structure physics. The project outcome will be reliable data on nuclear moments for research and applications.