The Monte Carlo method is used to simulate the beam optics of the WS beam line of RCNP, Osaka University in order to know the effect of collimators on the beam line to control the beam spot. According to the simulatio...The Monte Carlo method is used to simulate the beam optics of the WS beam line of RCNP, Osaka University in order to know the effect of collimators on the beam line to control the beam spot. According to the simulation, we do not need to use the collimator to cut the beam and the beam angular resolution can be better than 0.05° in achromatic mode. In the present paper, the actual beam condition during the beam adjustment is listed. The accelerator can provide a 12C beam in achromatic mode and the angular resolution σ=0.7775 mrad±0.0030 mrad.展开更多
In order to further obtain the information of three-body force （TBF） from 200-400 MeV/u ^12C＋^12C elastic scattering, we plan to perform this experiment on a SHARAQ spectrometer. Based on the experimental condition...In order to further obtain the information of three-body force （TBF） from 200-400 MeV/u ^12C＋^12C elastic scattering, we plan to perform this experiment on a SHARAQ spectrometer. Based on the experimental condition of the Radioactive Ion Beam Factory （RIBF）-SHARAQ facility, a simulation is given to find a compromise between the better energy and angular resolutions, and higher yield by optimizing the target thickness, beam transport mode, beam intensity and angular step. From the simulation, we found that the beam quality mainly limits the improvements of energy and angular resolutions. A beam tracking system as well as a lateral and angular dispersion- matching technique axe adopted to reduce the influence of beam quality. According to the two angular settings of SHARAQ as well as the expected cross sections on the basis of the theoretical model, the energy and angular resolutions, and statistical accuracy are estimated.展开更多
The Monte Carlo method is used to simulate the 12C＋12C reaction process. Taking into account the size of the incident 12C beam spot and the thickness of the 12C target, the distributions of scattered 12C on the MWPC ...The Monte Carlo method is used to simulate the 12C＋12C reaction process. Taking into account the size of the incident 12C beam spot and the thickness of the 12C target, the distributions of scattered 12C on the MWPC and the CsI detectors at a detective distance have been simulated. In order to separate elastic scattering from the inelastic scattering with 4.4 MeV excited energy, we set several variables： the kinetic energy of incident 12C, the thickness of the 12C target, the ratio of the excited state, the wire spacing of the MWPC, the energy resolution of the CsI detector and the time resolution of the plastic scintillator. From the simulation results, the preliminary establishment of the experiment system can be determined to be that the beam size of the incident 12C is Ф5 mm, the incident kinetic energy is 200-400 A MeV, the target thickness is 2 mm, the ratio of the excited state is 20%, the flight distance of scattered 12C is 3 m, the energy resolution of the CsI detectors is 1%, the time resolution of the plastic scintillator is 0.5%, and the size of the CsI detectors is 7 cm×7 cm, and we need at least 16 CsI detectors to cover a 0° to 5° angular distribution.展开更多
The simulation is performed for the monitors of beam direction and beam position for p-p elastic scattering. We set several variables to simulate the monitors of incident beam condition changes： beam positions at the...The simulation is performed for the monitors of beam direction and beam position for p-p elastic scattering. We set several variables to simulate the monitors of incident beam condition changes： beam positions at the quadrupole magnet and target in beam line polarimeter（BLP2）, distance between quadrupole magnet and target,size of plastic scintillators, distance between the target in BLP2 and the centers of plastic scintillators, and beam polarization. Through the rotation of the coordinate system, the distributions of scattered and recoiled protons in the laboratory system were obtained. By analyzing the count yields in plastic scintillators at di？erent beam positions,we found that the beam incident angular change（0.35°） could be detected when the asymmetry of geometries of left and right scintillators in BLP2 was changed by 6%. Therefore, the scattering angle measured in the experiment can be tracked by these monitors.展开更多
基金Supported by National Nature Science Foundation of China(11035007,11235002,11175011)State Key Laboratory of Software Development Environment(SKLSDE-2014ZX-08 as well as by the Key Laboratory of High Precision Nuclear Spectroscopy,Institute of Modern Physics,Chinese Academy of Sciences.)
文摘The Monte Carlo method is used to simulate the beam optics of the WS beam line of RCNP, Osaka University in order to know the effect of collimators on the beam line to control the beam spot. According to the simulation, we do not need to use the collimator to cut the beam and the beam angular resolution can be better than 0.05° in achromatic mode. In the present paper, the actual beam condition during the beam adjustment is listed. The accelerator can provide a 12C beam in achromatic mode and the angular resolution σ=0.7775 mrad±0.0030 mrad.
基金Supported by National Nature Science Foundation of China(11035007,11235002,11175011)
文摘In order to further obtain the information of three-body force （TBF） from 200-400 MeV/u ^12C＋^12C elastic scattering, we plan to perform this experiment on a SHARAQ spectrometer. Based on the experimental condition of the Radioactive Ion Beam Factory （RIBF）-SHARAQ facility, a simulation is given to find a compromise between the better energy and angular resolutions, and higher yield by optimizing the target thickness, beam transport mode, beam intensity and angular step. From the simulation, we found that the beam quality mainly limits the improvements of energy and angular resolutions. A beam tracking system as well as a lateral and angular dispersion- matching technique axe adopted to reduce the influence of beam quality. According to the two angular settings of SHARAQ as well as the expected cross sections on the basis of the theoretical model, the energy and angular resolutions, and statistical accuracy are estimated.
基金Supported State Key Laboratory of Software Development Environment (SKLSDE-2011ZX-20)National Natural Science Foundation of China (11175011)
文摘The Monte Carlo method is used to simulate the 12C＋12C reaction process. Taking into account the size of the incident 12C beam spot and the thickness of the 12C target, the distributions of scattered 12C on the MWPC and the CsI detectors at a detective distance have been simulated. In order to separate elastic scattering from the inelastic scattering with 4.4 MeV excited energy, we set several variables： the kinetic energy of incident 12C, the thickness of the 12C target, the ratio of the excited state, the wire spacing of the MWPC, the energy resolution of the CsI detector and the time resolution of the plastic scintillator. From the simulation results, the preliminary establishment of the experiment system can be determined to be that the beam size of the incident 12C is Ф5 mm, the incident kinetic energy is 200-400 A MeV, the target thickness is 2 mm, the ratio of the excited state is 20%, the flight distance of scattered 12C is 3 m, the energy resolution of the CsI detectors is 1%, the time resolution of the plastic scintillator is 0.5%, and the size of the CsI detectors is 7 cm×7 cm, and we need at least 16 CsI detectors to cover a 0° to 5° angular distribution.
基金Supported by National Nature Science Foundation of China(11035007,11235002,11175011)Special Joint Project of Beijing Municipal Education Commission
文摘The simulation is performed for the monitors of beam direction and beam position for p-p elastic scattering. We set several variables to simulate the monitors of incident beam condition changes： beam positions at the quadrupole magnet and target in beam line polarimeter（BLP2）, distance between quadrupole magnet and target,size of plastic scintillators, distance between the target in BLP2 and the centers of plastic scintillators, and beam polarization. Through the rotation of the coordinate system, the distributions of scattered and recoiled protons in the laboratory system were obtained. By analyzing the count yields in plastic scintillators at di？erent beam positions,we found that the beam incident angular change（0.35°） could be detected when the asymmetry of geometries of left and right scintillators in BLP2 was changed by 6%. Therefore, the scattering angle measured in the experiment can be tracked by these monitors.
