Quick Shot

Situated on the floor of the OMEGA Target Bay, a midbeam collimator is positioned between the target chamber and an advanced neutron time-of-flight (nTOF) detector. The nTOF detector is used to measure the neutron spectrum emitted from deuterium–tritium (DT) fusion reactions in cryogenic implosions. Analysis of the spectrum provides important information on the implosion performance. DT neutrons scattered from the target chamber and other structures in the Target Bay can distort the shape of the measured neutron spectrum, leading to incorrect conclusions about the implosion. Neutron transport simulations, common in the nuclear power industry, were used by University of Rochester physics graduate student Chad Forrest (shown aligning the collimator) to define the field of view required for the collimator to mitigate a background of scattered neutrons.