Measurement The Reaction Cross Section And The Neutron Removal Cross Section Of ¹⁶C

In recent 20 years, with the rapid development of accelerator technology and particle detection technology, the development of experimental methods and theoretical research, people have a new understanding on the nuclear structures, the halo structure is one of them. For the neutron rich exotic nuclei, the information about the nuclear reaction and structure and density distribution can be obtained from the total reaction cross section and the neutron removal cross section.It is pointed out that the exotic structure of halo nuclei have a typical physical phenomenon that the total reaction cross section is much larger than the stable nucleus and the separation energy of valence nucleon is small, which is a necessary condition for the formation of the halo structure.The narrow momentum distribution of the core of the halo nucleus can be explained by the uncertainty principle in quantum mechanics, which is the fundamental characteristic of the halo structure. We can get a more accurate information about valence nucleon distribution, which can further confirm whether there is halo structure, through experimental measurements of total reaction cross section and removal neutron cross section and momentum distribution width of fragment. In this paper, we focus on the halo structure of the neutron drip line nuclear16 C. In this paper, focusing on the halo structure of the neutron rich nuclear 16 C, we had measured the total cross section and the neutron removal cross section, and extracted the information of the nucleon density distribution in order to study whether the 16 C has a halo structure.The experiment was carried on at the Radioactive Ion Beam Line in Lanzhou(RIBLL).38 Me V/u16 C secondary beam bombarded at a12 C target, three Parallel-Plate Avalanche Counters(PPAC) placed before the target were used to measure the position of the incident particle. A △E-E telescope detector, placed behind the target, was used to identify the fragments and measure the complete kinematic. The telescope consists of a double-sided silicon detector(DSSD) which each side has 16 strips and a 8 * 8Cs I(Tl) detector, can identify the fragments and measure the energy and position. The experimental data obtained from the system can be processed and analyzed to obtain the total cross section and the one- and two-neutron removal cross section of16 C.The finite-range Glauber-model calculation was used to analyzed the experimental data. The theoretical results was found to be in good agreement with the experimental ones in inter medium and high energy, while is slightly low than the experimental ones in the low energy region. Suppose that 16 C mainly having a core plus valence neuclon structure and shows a strong contribution of(2s1/2)2 for valence neutron, the core distribution and density of HO valence neutron density distributions extracted 16 C corresponding density distribution parameters fitting calculated the theoretical and experimental values in the low energy region can be well in line. In this experiment,the total reaction cross section and the neutron removal cross section of 16 C are measured at the energy of 38 AMe V. The results of theoretical analysis and experimental results are in good agreement with the experimental ones.