| Wilhelm Roentgen discovered x-rays in 1895, and then did the research on the x-ray radiography, the radiography has been developed. Nowadays, the technology of radiography has been developed a rounded system, whose imaging particle include x-ray, proton, neutron, muon, and so on, and also incude so many imaging methods, such as static imaging, tomography (ICT) 3-dimension imaging, dynamic imaging...These technology also has benn used in medical, physics, archaeology, and military areas.In order to take stop action pictures of dynamic events:from the detonation of high explosives to the implosion of a mock weapon assembly containing a surrogate material for the nuclear core, to investigate the density distribution, structure of the material, the flash radiography has been developed. But there are still some problem cannot be solved by flash radiography, such as how to cancel the image blur due to the scattering particles, how to control the beam spot size of x-ray, how to increase the penetration rate of x-ray. Compared with x-ray, heavy charged particles like proton has obvious advantages in penetrate power, focusing property, detect efficiency, the higher resolution can be expected. So proton radiography has been treated as the next generation of radiography technology, it has became a hot topic in high energy density image field, has been discussed and wide concern.Base on the Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring (HIRFL-CSR), a high energy proton radiography beam line has been proposed. The paper has studied the following aspects base on above plan.The interaction between proton and target atomic has been investigated, which include Coulomb interaction between proton and extranuclear electron, poulomb interaction between proton and nucleus, nuclear interaction between proton and nucleus. The basic principle of proton-scattering radiography and magnetic lens proton radiography has been explained, whose advantage and disadvantage also are discussed. The principle of Zumbro lens system and twice proton radiography system are also been studied. Moreover, the computational method about spatial resolution, density resolution and demanded incident proton flux are investigated.In order to choose the optimize material of diffuser, the simulation has made the 1GeV proton transport through the diffuser which is made of W, Ta and Cu respectively by using Geant4 code. The relationship of normniformity of tramission proton, penetration rate, average scattering angle and energy loss rate with thickness of diffuser has been calculated from the simulation data. As a result, the optimize material of diffuser is W or Ta, the optimize thickness is from 2cm to 5cm for 1GeV proton.A proton-scattering radiography simulation has been made with Geant4 code. From the data at the image plane, a magnify image is geted, the magnification factor is decided by the geometric parameters. For cylinder model, the spatial resolution is about 63μm; for FTO model, the boundary between different material can be seen clearly from the 2D image result, but cannot be calculated the spatial resolution from the simulation data because of the impact by multiple coulomb scattering. In order to cancel the image blur by multiple coulomb scattering, the image lens system has to be included.Based on the proposed proton radiography beam line which will be built at HIAF, a series simulation has been made by optic software WINAGILE and My-BOC, and Monte Carlo toolkit Geant4 and G4beamline.Firstly, we use beam optic software WINAGILE and My-BOC to calculate the geometric parameters for 2.6GeV proton. Then simulate the whole proton radiography beam line which includes matching lens, imaging lens and ideal detector by using G4beamline, test the transport efficiency. Stripes sample and steps sample is put at the object plane respectively to test its spatial resolution and density resolution. From the final result, the best spatial resolution is about 35μm, the best density uncertainity is better than 2%. For FTO model, the spatial resolution is 153μm, all boundary of different material can be seen clearly, which is better than the result from proton-scattering radiography.The simulation is made for high energy proton pass through the heavy ion radiography terminal by Monte Carlo code G4beamline. Moreover, the image simulation is also made for stripes sample in the proton radiography beam line. From the simulation data the spatial resolution of stripes edge is calculated which is 54μm.The carbon ions radiography experiments are made with stripes sample and steps sample respectively at heavy ion raidography terminal of HIRFL-CSR. The energy of carbon ions in twice experiments are 600MeV/u and 300MeV/u respectively. For stripes sample, the experiment result shows the structure of stripes can be seen clearly, the spatial resolution is 90μm. And for steps sample, the spatial resolution can’t be calculated because the boundary of step not can be seen clearly, so the further improvement for the experiment is the next step work. |
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