Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS), the transmutation for nuclear wastes such as 137Cs and 129I is investigated. It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO_2 laser photons and 3.5 GeV electrons. The nuclear activities of 137Cs and 129I are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser. Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons, the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method.
Using an isospin-dependent quantum molecular dynamics (IQMD) model, we study the 15C induced reactions from 30-120 MeV/nucleon systematically. Here the valence neutron of 15C is assigned at both 1d5/2 and 2s1/2 states respectively in order to study the density effect of reaction mechanism. It is believed that the existent neutron halo structure at the 2s1/2 state of 15C will affect the light particle emission evidently. In our calculation, the different density distributions of 15C at two states are calculated by relativistic mean field (RMF) model and introduced in the initiation of IQMD model, respectively. It is found that some observables such as emission fragmentation multiplicity, emission neutron/proton ratio and emission neutrons' kinetic energy spectrum are sensitive to the initial density distribution.
The dependence between neutron skin thickness and neutron abrasion cross section (σ nabr) for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model.Assuming that the density distributions for proton and neutron are of Fermi-type,and adjusting the diffuseness parameter of neutron density distribution in the droplet model,we find out the good linear correlation between the neutron skin thickness and the abrasion cross section σ nabr for neutron-rich nuclei.The uncertainty of neutron skin thickness determined from σ nabr is very small.It is suggested that σ nabr can be used as a new experimental observable to extract the neutron skin thickness for neutronrich nucleus.The scaling behaviours between neutron skin thickness and σ nabr,separately,for isotopes of 26 35 Na,44 56 Ar,48 60 Ca,67 78 Ni are also investigated.
