Abstract. A fast-slow coincidence scintillation spectrometer for gamma-gamma cascade measurements following thermal neutron absorption in nuclei is now in operation at the Livermore 1-megawatt pool-type reactor. Design features of the spectrometer and experimental techniques in its use are discussed with particular emphasis on the application of the recently introduced sum-coincidence method for analysis of capture-gamma double cascades. A new technique for the determination of added neutron binding energy is presented and various types of coincidence data from appropriate experiments are illustrated.