Several interesting characteristics of the PS‐1 spheromak plasma have been inferred from one‐dimensional simulations of the implosion phase of the experiment. The calculations demonstrate that metallic impurities in the pre‐imploded plasma, which come from the electrodes, strongly affect the dynamics of the implosion. The simulations also indicate that the resistivity and Joule heating are much larger than their classical values, suggesting that microinstabilities are a principal source of ion heating. Finally, the calculations suggest the existence of a hot, low‐density plasma between the plasma column and the wall, which carries a non‐negligible fraction of the poloidal current.