We study the sensitivity of the r -process abundance pattern to neutron capture rates along the rare earth region ( A \sim 150 to A \sim 180 ) .
We introduce the concepts of large nuclear flow and flow saturation which determine the neutron capture rates that are influential in setting the rare earth abundances .
We illustrate the value of the two concepts by considering high entropy conditions favorable for rare earth peak production and identifying important neutron capture rates among the rare earth isotopes .
We also show how these rates influence nuclear flow and specific sections of the abundance pattern .