Disintegration of 12C nuclei by 700–1500 MeV photons

Disintegration of C-12 nuclei by tagged photons of 700-1500 MeV energy at the GRAAL facility has been studied by means of the LAGRAN gamma E detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of C-12 into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on C-12 in the same energy range is also reported.