Fen Fu

Code Development and Target Station Design for Chinese Accelerator-Driven System Project

Abstract The Institute of Modern Physics, Chinese Academy of Sciences performs research and development on the target station of an accelerator-driven system (ADS) under the China ADS project. A newly developed Monte Carlo program for the design of the target station named GMT1.0 is presented. The program is designed for a massively parallelized simulation of the initiative granular-flow target concept. Based on the combination of the Intranuclear Cascade of Leige (INCL) model and the ABLA evaporation/fission model, GMT1.0 integrates a particle transport code and a nuclear reaction code to simulate a spallation target. For validation, a series of calculations of neutronics characteristics and heat-deposit distributions of solid targets were performed, and a high degree of accuracy was shown for GMT1.0. Using GMT1.0, a systematic study of the neutron economy of the target was performed and the neutronics characteristics of the most optimal parameters were illustrated well.

Nuclear matter at a HIRFL-CSR energy regime

We report some recent progress in constraining the symmetry energy Esym(ρ) at high densities using high-energy heavy-ion collisions. Circumstantial evidence of a soft Esym(ρ) at supra-saturation density is obtained by comparing the pion ratio π−/π+ measured recently with FOPI at GSI and the IBUU04 model calculations. Detailed studies indicate that the power of determining the Esym(ρ) from π−/π+ is enhanced with decreasing the beam energy to near the pion production threshold, showing a correlation to the increasing nuclear stopping. Among several heavy-ion reaction facilities in the world, the cooling storage ring (HIRFL-CSR), newly commissioned at Lanzhou, delivering heavy-ion beams up to 1 A GeV, to be coupled with advanced detectors will contribute significantly to further studies of the equation of state of asymmetric nuclear matter.

7Be, 8B+208Pb Elastic Scattering at Above-Barrier Energies

Angular distributions for the elastic scattering of 7Be and 8B by an enriched 208Pb target were measured at the Radioactive Ion Beam Line at Lanzhou (RIBLL). The incident energies of the radioactive beams were about three times the respective Coulomb barriers. A suppressed Coulomb-nuclear Interference Peak (CNIP) is not observed for 8B, a pronounced proton halo nucleus. Optical model fits were performed using Woods-Saxon potentials and the total reaction cross sections deduced. The results are discussed.