The interior of the giant planets of our Solar System can be described in simple terms as consisting of a core of unknown composition surrounded by fluid envelopes (Guillot, 2005). For Jupiter, the core could be small and dense, but also large and dilute (Wahl et al., 2017). The overlying envelopes consist of an inner layer of metallic hydrogen and an outer layer of molecular hydrogen. Recent experimental results describe a transition H-He demixing layer, suggesting Helium rain between depths 0.68 and 0.84 R J (Jupiter's equatorial radius, 1 R J = 71,492 km) (Brygoo et al., 2021). The high temperature and pressure inside the planet renders it electrically conducting. Convection in the electrically conductive metallic hydrogen generates the strong Jovian magnetic field (Jones, 2011(Jones, , 2014. In contrast to rocky bodies, Jupiter does not have an abrupt change between its metallic hydrogen (magnetic source) and molecular hydrogen (source free) regions. The change is expected to be gradual. The electrical conductivity profile of the different hydrogen layers at different depths from an ab-initio simulation (French et al., 2012) does not indicate a clear value of the dynamo region radius. Previous attempts to constrain this radius using the magnetic energy spectrum place it somewhere between 0.80 and 0.90