Temperature of intermediate mass fragments in simulated ^(40)Ca + ^(40)Ca reactions around the Fermi energies by AMD model

The primary fragments in ^(40)Ca +^(40)Ca reactions at 35,50,80,100,140,and 300 MeV/u were simulated using the antisymmetrized molecular dynamics model,in the phase space at t=300 fm/c with a coalescence radius R_c=5 fm.The standard Gogny interactions g0,g0 as,and gOass were adopted in simulating the collisions at an impact parameter of b=0 fm.It was found,using an isobaric yield ratio method,that temperature of the primary fragment depends on the incident energy and hardness of the interaction potential.The temperature obtained in this work agrees with the results by the self-consistent fitting method.

Improved FRACS parameterizations for cross sections of isotopes near the proton drip line in projectile fragmentation reactions

The FRACS parameterizations,labeled as FRACS-C,have been improved in order to predict the presence of isotopes near the proton drip line produced in projectile fragmentation reactions.By investigating the cross sections for proton-rich isotopes in a series of reactions with energies ranging from intermediate to relativistic,it is shown that the FRACS-C parameterizations can predict isotopes near the proton drip line considerably well.The FRACS-C parameterizations are suggested to serve as an effective tool for predicting the presence of proton-rich isotopes with large asymmetry in a projectile fragmentation reaction.Different reactions have been investigated to check these results.

Binding energies of near proton-drip line Z = 22-28 isotopes determined from measured isotopic cross section distributions

A new method is proposed to determine the binding energy(B)of near proton-drip line isotopes from isotopic cross section distribution.To determine B of Z=22-28 isotopes(with T_z=-2 and-5/2),the lack of cross sections for proton-rich isotopes in the 345A MeV^(78)Kr+~9Be is overcome by predicting the proton-rich isotopes from a newly discovered scaling phenomenon found in the proton-rich isotopes measured in the 140A MeV^(40,48)Ca(^(58,64)Ni)+~9Be reactions.The cross sections for proton-rich isotopes are verified to exponentially depend on the average binding energy per nucleon,based on which B of the Z=22-28 isotopes with T_z=-2 and-5/2 are determined from cross sections.The determined B of the isotopes are justified from obeying the scaling phenomenon of the difference between the mass of mirror nuclei.The cross sections for the Z=22-28 isotopes with T_z=-1 and-3/2,which in potential can be experimentally studied in mass storage ring,are also predicted.

A scaling phenomenon for the cross section of fragment produced in projectile fragmentation reactions

A scaling phenomenon has been found for the cross section of a fragment, which is defined as a "square" cross section(SCS).This phenomenon can unify the cross sections of fragments in projectile fragmentation(PF) reactions. An empirical formula is proposed to calculate SCSfor a fragment with parameters determined by an extensive investigation of measured reactions ranging from Fermi energies to relativistic energies. The scaling phenomenon of SCShas been verified using different techniques,showing that the scaling of SCSgenerally exists in PF reactions. The concept of SCS, which can be assumed as a standard value for a fragment, is shown to accurately predict the cross sections of isotopes in PF reactions with incident energies ranging from tens of A MeV to approximately 1000 A MeV.

Cross-section prediction for isotopes near neutron drip line in 70, 80Zn projectile fragmentation reactions

The cross sections for 59,60Ca, recently measured in the 345 A MeV 70Zn+9 Be reaction,were estimated using the FRACS parametrization and an empirical formula,which are in good agreement.The FRACS parametrization and the empirical formula are combined to predict the cross sections for extreme calcium isotopes 66,70Ca in the70,80Zn+9 Be reactions at the incident energies of 60,80,and 345 A MeV.The dependence of emperical formula parameters on the reaction system,as well as the incident energy,are discussed.The results indicate that 66,70Ca can be discovered in reactions of 60,80A MeV 80Zn+9 Be.The predicted binding energy for extreme neutron-rich isotopes by the spherical relativistic continuum Hartree-Bogoliubov theory was adopted in the calculation.Hence,the planned Beijing Isotope-Separation-On Line Neutron-Rich Beam Facility(BISOL),which is a third generation radioactive ion beam facility,could provide the opportunity to discover 66,70 Ca and neighboring neutron-drip line nuclei.

Predictions for cross sections of light proton-rich isotopes in the ^(40)Ca + ~9Be reaction

The cross sections for Z=10-19 with isotopes Tz=-3/2 to -5 in the 140A MeV 40Ca ＋ 9Be projectile fragmentation reaction have been predicted. An empirical formula based on the correlation between the cross section and average binding energy of an isotope has been adopted to predict the cross section. The binding energies in the AME16, WS4, and the theoretical prediction by the spherical relativistic continuum Hartree-Bogoliubov theory have been used. Meanwhile, the FRACS parametrization and the modified statistical abrasion-ablation model are also used to predict the cross sections for the proton-rich isotopes. The predicted cross sections for the Tz=-3 isotopes are close to 10-10 mb, which hopefully can be studied experimentally. In addition, based on the predicted cross sections, Z=14 is suggested to be a new magic number in the light proton-rich nuclei with Tz ≤ -3/2, for which the phenomenon is much more evident than it is from the average binding energy per nucleon.