Subsurface Inspection with X-ray Generated Positrons

PI提出了一种高能背散射成像的构建方法， 用于金属和其他高强度材料无损检测的系统 密度材料。 这样的系统将是有用的应用程序 其中高密度阻止了康普顿反向散射的使用， 其中空气间隙阻止了噪声比的传输， 高能X射线产生的电子/正电子对的高产量 以及由此产生的韧致辐射的近各向同性性质， 湮灭辐射 PI之前的蒙特卡罗模拟表明，这种反向散射 系统能够成像材料的深度，允许 0.511 MeV湮没光子和韧致辐射光子的出射 主要由韧致辐射和正电子湮灭组成 辐射，空间分辨率和对比度歧视 系统强烈地依赖于平均自由程， 电子在材料中成像。 因此， 必须对原始散射进行数学校准 轮廓以获取有关形状、深度和 地下成分的组成。 这项技术没有 替代现有无损检测。

PIs' proposed the construction a high-energy backscatter imaging system designed for nondestructive testing of metals and other high density materials. Such a system will be useful for applications where high density prevents the use of Compton backscatter and where air gaps prevent the transmission of noise ratio because of the high yield of electron/positron pairs from high-energy X-rays and the near-isotropic nature of the resulting bremsstrahlung and annihilation radiation. PIs' previous Monte Carlo simulations show that this backscatter system is capable of imaging materials to depths that permit the exit of 0.511 MeV annihilation photons and bremsstrahlung photons composed primarily of bremsstrahlung and positron-annihilation radiation, the spatial resolution and contrast discrimination of the system are strongly dependent upon the mean free paths of the electrons in the materials imaged. For this reason, it is necessary to perform mathematical calibration of the raw scatter profiles to obtain information about the shape, depth and composition of the subsurface components. This technique has no substitute in existing nondestructive testing.