Kippenhahn diagram and maximal neutron density of the 1 M_⊙ model with [Fe/H] = −3.0 during the PIE while considering different values for the convective velocity: the standard case (top left), v_conv divided by 10 (top right), 100 (bottom left), and 1000 (bottom right). The dotted green and blue lines in the Kippenhahn diagram correspond to the maximum nuclear energy production by hydrogen- and helium-burning, respectively. The dashed green and blue lines delineate the H- and He-burning zones (when the production of energy by H- and He-burning exceeds 10 erg g⁻¹ s⁻¹).