The high temperatures and densities of the 25M$_\odot$ star facilitate the production of many of the radioactive isotopes in our study in the bottom of the helium-burning layer. Because the final remnant mass of the 25M$_\odot$ is so large, most of the radioactive isotopes ejected in this model arise from yields produced in this shell.

Explosions
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The explosions were calculated using the 1-dimensional core-collapse code described in @herant94, @fryer99. This code includes general relativistic effects (spherically symmetric), an equation of state for dense nuclear matter combining the Lattimer-Swesty equation of state at high densities [@lattimer91] and the Blinnikov equation of state at low densities [@blinnikov96], and an 18-isotope nuclear network [@fryer99]. The progenitor star is mapped into this 1-dimensional code through linear interpolation at collapse and the star is followed through collapse and bounce. After the stall of the bounce shock, the core is removed as a neutron star remnant and a hard boundary is placed at the position of the core (defined by where the density drops dramatically from $10^{13-14} {\rm g \,
cm^{-3}}$ to $10^{11} {\rm g \, cm^{-3}}$). At this time, an artificial energy source is introduced. The work by @Fryer_2018 used a range of powers, 