Experimental Study On Double Differential Thick Target Neutron Yields From ⁴He And ¹²C Induced Reaction And High Energy Neutron Transport In Beryllium

High intensity accelerators play an important role in radiotherapy,material science,space radiation,isotope production,nuclear energy and fundamental research of nuclear physics.Accelerator Driven Subcritical System（ADS）uses neutrons producing by high-energy protons bombarding spallation targets to transmute nuclear waste and realize the proliferation of nuclear fuel.It is considered to be a safe,clean and promising nuclear energy technology.The design of ADS and the research of its neutronics need accurate and reliable nuclear data.In ADS,high intensity protons bombard spallation targets,producing a large number of secondary neutrons and charged particles.The nuclear data of secondary neutrons produced by the charged particles induced reaction in important materials and high-energy neutron transport in beryllium are the basis for studying the radiation protection of high intensity accelerator,the design of spallation target and the neutronics in the target reactor coupling region in ADS.Based on the nuclear data requirements,this paper performed the experiment of secondary neutron yields from helium ions and carbon ions induced reaction and high-energy neutron transport in beryllium,which is of great significance for ADS design and neutronics research.Based on the RIBLL1 experimental setup in Institute of Modern Physics,Chinese Academy of Sciences,the secondary neutron energy spectra from beryllium,carbon,tungsten and lead targets bombarded by 26.7 Me V/u ⁴He and 80.5 Me V/u ¹²C ions at different angles were measured by time-of-flight method.After the analysis of the experimental data,the secondary neutron energy spectra,double differential neutron yields and neutron angular distribution are obtained.Meanwhile,Monte Carlo particle transport codes,such as GEANT4,PHITS and FLUKA,are used to simulate the experiment with INCL,JQMD-2.0 and BME physical models.In ⁴He induced reaction experiment,the results show that GEANT4 with INCL physical model reproduces the experimental data for beryllium and carbon targets.PHITS with JQMD-2.0 physical model significantly overestimates the intermediate energy neutron yield at 0°for all targets.FLUKA with BME physical model agrees well with the experimental data for tungsten and lead targets.In the ¹²C induced reaction experiment,the results of the three simulation codes are similar for beryllium and carbon targets and in good agreement with the experimental data.For tungsten and lead targets,the neutron spectra at 0°from GEANT4 is quite different with the experimental data.And the simulation results from GEANT4 are significantly underestimated experimental data at 37°and 60°.In general,in ⁴He induced reaction experiment,GEANT4 used INCL physics model agrees well with the experimental data for light target,while FLUKA with BME physical model match the experimental data best for heavy target.In ¹²C induced reaction experiment,the simulation results of PHITS with JQMD-2.0 physical model are in good agreement with the experimental data for all targets.The differences between the simulation results and the experimental data are analyzed,and suggestions are made for the further improvement of the physical models.Based on the neutron benchmark experimental facility at China Institute of Atomic Energy,the measurement of neutron from D-T reaction transport in polyethylene and graphite was carried out.The reliability of GEANT4 and PHITS simulating the transport of 14.8-Me V neutron in polyethylene and graphite materials is verified through benchmarks.The experiment of high energy neutron transport in beryllium target was also performed at RIBLL1 experimental setup.High-energy neutrons produced by 80.5Me V/u ¹²C ion bombarding tungsten transport in beryllium sample and the leakage neutron spectra were measured at 0°with liquid scintillator detector.Meanwhile,the experiment is simulated by PHITS with INCL,GEANT4 with INCL,BIC and BERT physics models and ENDF/B-VIII.0、JEFF-3.3、JENDL-4.0 libraries.These physics models and libraries reproduced the experimental data well.By comparing the simulation results with the experimental data,the reliability of GEANT4 and PHITS simulating high-energy neutron transport in beryllium materials is verified.