  For relativistic heavy ion collisions the energy flow in the collision
reveals information on the equation of state of matter at high density. The
BRAHMS experiment has studied the relation between multipliciity in the
sidewards direction and zero degree energy using our Tile Multiplicity Array
and Zero Degree Calorimeters. To understand this spectrum requires a knowledge
of the coalesence of nucleons that are close in phase space. We have also
studied electromagnetic collisions and compared our results to lower energy
data. As the center of mass energy increases, each nucleus sees a stronger
electromagnetic field resulting in more energy being absorbed. This in turn
causes an increase in the neutron multiplicity.
