The Ladon Facility

LADON, a facility providing a monochromatic polarised gamma-ray beam, obtained by backward Compton scattering of laser light on the electrons stored in ADONE, showed up to be a very efficient tool for experiments in nuclear physics because of its unique characteristics:

• high energy resolution;
• full or operator adjustable polarisation;
• very low background of different energy and polarisation photons;
• energy adjustable between 5 and 80 MeV;
• intensity fulfilling requirements of photonuclear reactions experiments.

LADON has been utilised for the detailed study of photonuclear reaction on light and heavy nuclei. In particular the asymmetry factor of deuterium photodisintegration has been measured at several energies between 20 and 70 MeV, giving clear experimental indications for a correct theoretical description.

Moreover, precise measurements of total cross sections of two body photodisintegration of deuterium and Helium4 clarified some unexplained problems and wrong interpretations of experimental data about the reactions

gamma + d -> p + n
gamma + He4 -> tritium + p
gamma + He4 -> He3 + n

Another research line was the study of quasi-deuton reactions in intermediate nuclei such as silicon, and photofission reactions in heavy nuclei.

The LADON group hosted researchers and technicians from Frascati, the two Universities in Rome, Istituto Superiore di Sanita’ and their associated INFN sections. The experience gained at ADONE is now being exploited at Brookhaven and at ESRF in Grenoble, by performing experiments which extrapolate to much larger energies (0.2÷ 2.0 GeV) the techniques developed in Frascati.