What is is the main source of energy production in the inner core and outer core of earth?

The main source of energy production in Earth's inner and outer core is the decay of radioactive isotopes, such as uranium and thorium, along with the heat generated from the gravitational compression of materials during Earth's formation. Additionally, the inner core's solid state and high pressure contribute to the generation of geothermal energy through the release of latent heat as it cools. This process drives the convection currents in the outer core, which are crucial for generating Earth's magnetic field.