The Compound-Nuclear Reaction and Related Topics (CNR*) international workshop series was initiated in 2007 with a meeting near Yosemite National Park. It has since been held in Bordeaux (2009), Prague (2011), Sao Paulo (2013), Tokyo (2015), and Berkeley, California (2018). The workshop series brings together experts in nuclear theory, experiment, data evaluations, and applications, and fosters interactions among these groups. Topics of interest include: nuclear reaction mechanisms, optical model, direct reactions and the compound nucleus, pre-equilibrium reactions, fusion and fission, cross section measurements (direct and indirect methods), Hauser-Feshbach theory (limits and extensions), compound-nuclear decays, particle and gamma emission, level densities, strength functions, nuclear structure for compound-nuclear reactions, nuclear energy, nuclear astrophysics, and other topics. This peer-reviewed proceedings volume presents papers and poster summaries from the 6th International Workshop on Compound-Nuclear Reactions and Related Topics CNR*18, held on September 24-28, 2018, at Lawrence Berkeley National Lab, Berkeley, CA.

The symposium covered the following topics: Physical foundation of preequilibrium reaction models; Randomness in nuclei and nuclear reactions; Statistical multistep compound and direct reactions; Exit channels in nuclear reactions: n, p, α, and γ-emission as well as fission; Multiple emission processes; Parameter systematics for nuclear model calculations; New approaches to angular distributions; Experiments for reaction mechanism studies; Applications for nuclear data evaluation.

While we have attempted to mention at least the most important developments in the theory of pre-equilibrium reactions, the volume of work in this area over the last few years has been so immense that it is not possible to give a comprehensive account of all that has been done. Our aim is to describe as clearly as we can the main physical ideas and to sketch the mathematical formulations that have been developed to enable practical calculations to be made. We attach particular importance to the detailed comparisons between theory and experiment because only in this way is it possible to assess the usefulness and validity of the theories that have been proposed.