We analytically study the problem of pore detection and certification in bulk objects by means of radiography. For an absorbent sample, the optimum thickness for pore imaging and detection is expressed in terms of the linear attenuation coefficient of the material. This can be used to maximize the signal-to-noise ratio by tuning the photon energy of the incident monochromatic beam. The problem is more complicated for transparent objects. An evident approach is radiography in coherent beams; in this case, we use a simple model allowing to find the field structure of the transmitted beam on the backside of the sample and beyond in the outer half space in terms of few dimensionless parameters, including the Fresnel number F = a²/λz, where a is the pore radius, λ is the wavelength, z is the distance from the back side of the sample to the detector, and the phase number Φ = akδ, with k = 2π/λ and δ being the bulk material decrement. The detailed analysis of this field structure is performed that can be used to find the optimum position of a detector revealing the pores parameters from the intensity distribution measured. We present the numerical results for a Gaussian type of the pore shape function and provide the software to calculate the space field structure for other pore shape functions. The stationary phase method in higher orders, used here to simplify the Fresnel integral, can be applied to extend the obtained results to 3D geometry. The suggested qualitative picture of the formation of images of pores as phase objects complements modern methods of monitoring porous-sensitive materials.

我们通过射线照相法分析研究了散装物体中的孔检测和认证问题。对于吸收性样品，用于孔成像和检测的最佳厚度用材料的线性衰减系数表示。通过调整入射单色光束的光子能量，可以将其用于最大化信噪比。对于透明对象，此问题更为复杂。一种明显的方法是在相干光束中进行射线照相。在这种情况下，我们使用了一个简单的模型，允许发现在样品的和超出所述外半空间背面上的发射波束的场结构中的几个无量纲参数，包括菲涅耳数术语˚F =一个² / λZ，哪里一个是孔半径，λ是波长，Ž是从样品到检测器的背面侧的距离，和相位数Φ= akδ，与ķ = 2 π / λ和δ是散装物料减量。对该场结构进行了详细的分析，可用于找到检测器的最佳位置，从而从测量的强度分布中揭示出孔隙参数。我们提出了高斯类型的孔隙形状函数的数值结果，并提供了计算其他孔隙形状函数的空间场结构的软件。可以使用此处用来简化菲涅耳积分的高阶固定相方法，将获得的结果扩展到3D几何形状。所建议的定性的关于作为相对象的孔的图像形成的图片补充了监测多孔敏感材料的现代方法。