Fragmentation Of ¹²C On C Targets At 290 A MeV

Fragmentation of ¹²C on C targets at the highest beam energy of 290 A Me V is investigated by using CR-39 plastic nuclear track detector.The beam energies on each C target is 280 A Me V,267 A Me V,254 A Me V and 241 A MeV respectively.The total charge-changing cross sections,the partial cross sections of projectile fragment production,the scattering angle of beam ions and emission angle of projectile fragments are calculated by the statistics of the number of projectile fragment and the number of survived beam ions after the beam ions pass through each target.It is found that the total charge-changing cross sections are the same as the prediction Bradt-Peters semi empirical formulas and the corresponding results at close beam energies within experimental errors,the total charge-changing cross sections do not obviously depend on the beam energy,the partial cross sections of projectile fragment production is also do not obviously depend on the beam energy.The angle of the peak of emission angle distribution for projectile fragments is greater than that of the scattering angle distribution for beam ions at fixed beam energy,and this value increases with the decrease of beam energy.Generally speaking,the emission angle of projectile fragments is greater than the scattering angle of beam ions at fixed beam energy.These results are useful not only to heavy ion therapy,cancer treatment and radiation protection,but also to refine the models of the origination and propagation of galactic cosmic-ray.