Projectile fragment emission in the fragmentation of 56Fe on Al,C,and CH2 targets

The emission angle distribution of projectile fragments(PFs)and the temperature of PF emission sources for fragmentation of 56Fe on polyethylene,carbon,and aluminum targets at the highest energy of 497 A MeV are investigated on the basis of corrected data,using a CR-39 plastic nuclear track detector.It is found that the average emission angle of PFs increases with the decrease in PF charge for the same target,and no obvious dependence of angular distribution on the mass of the target nucleus is found for the same PF.The cumulative squared transverse momentum distribution of PFs can be well represented by a single Rayleigh distribution.The temperature of PF emission sources is extracted from the distribution,and it is about 1.0-8.0 MeV and does not depend on the mass of the target for PFs with charges of 9≤Z≤25.

Charge-Changing Cross Sections of 736 A MeV ^(28)Si on Carbon Targets

The total and partial charge-changing cross sections of 28 Si on carbon targets at 736 and 723 A Me V are studied by CR-39 plastic nuclear track detectors using the HSP-1000 microscope system and the PitFit track measurement software. The values of the total charge-changing cross section are σtot=（11794-50） mb and σtot=（11864-42） mb at 736 and 723A MeV, respectively. The result is compared with the ones obtained by other experimental and theoretical results. The odd-even effect of the partial charge-changing cross section is observed.

The fragmentation of ^(20)Ne at 400 A MeV

The total charge-changing cross sections and partial cross sections for the production of projectile fragments are measured in the interactions of 400 A MeV 20 Ne with aluminum,carbon and polyethylene targets sandwiched with CR-39 plastic nuclear track detectors.The measured total charge-changing cross sections are compared with the predictions using the Bradt-Peters semi-empirical formula,and the NUCFRAG2 and PHITS models.It is shown that the measured experimental results are in good agreement with the theoretical model prediction and other experimental results,and it can be clearly seen that the partial cross sections for fragment production show obvious odd-even effects.

Projectile fragment emission in the fragmentation of ^(56)Fe on C,Al and CH_2 targets at 471 A MeV

The emission angle and the transverse momentum distributions of projectile fragments produced in the fragmentation of 56Fe on CHs, C and A1 targets at 471 A MeV are measured. It is found that for the same target, the average value and width of the angular distribution decrease with an increase of the projectile fragment charge; for the same projectile fragment, the average value of the distribution increases and the width of the distribution decreases with increasing the target charge number. The transverse momentum distribution of a projectile fragment can be explained by a single Gaussian distribution and the averaged transverse momentum per nucleon decreases with the increase of the charge of projectile fragment. The cumulated squared transverse momentum distribution of a projectile fragment can be explained well by a single Rayleigh distribution. The temperature parameter of the emission source of the projectile fragment, calculated from the cumulated squared transverse momentum distribution, decreases with the increase of the size of the projectile fragment.