A Novel Multi Slit X-Ray Backscatter Camera Based on Synthetic Aperture Focusing

A special slit collimator was developed earlier for fast acquisition of X-ray back scatter images. The design was based on a twisted slit design (ruled surfaces) in a Tungsten block to acquire backscatter images. The comparison with alternative techniques as the flying spot and the coded aperture pin hole technique could not prove the expected higher contrast sensitivity. In analogy to the coded aperture technique, a novel multi slit camera was designed and tested. Several twisted slits were parallelly arranged in a metal block. The CAD design of different multi-slit cameras was evaluated and optimized by the computer simulation packages aRTist and McRay. The camera projects a set of equal images per slit to the digital detector array, which are overlaying each other. Afterwards, the aperture is corrected based on a deconvolution algorithm to focus the overlaying projections into a single representation of the object. Furthermore, a correction of the geometrical distortions due to the slit geometry is performed. The expected increase of the contrast-to-noise ratio is proportional to the square root of the number of parallel slits in the camera. However, additional noise has to be considered originating from the deconvolution operation. The slit design, functional principle, and the expected limits of this technique will be discussed

Innovation and Institutional Environment for Hi-tech Industrial Development: The case of Shanghai

Tools for computer simulation are helpful in NDE manyfold. A global conception of reliability in NDE can include among other procedures performance prediction by computer simulation. POD data of simulated defects can be calculated. Computer simulation gives the possibilities to optimize testing parameters, to make feasibility analysis for special testing problems, and to support the interpretation of testing results especially in case of complex component geometry. In this way simulation tools are valuable for planning and for evaluating of the examinations

Simulation of Scattering Process in Radiation Techniques Exploiting the Theory of Markovian Processes with Random Structure

There are a lot of physical and technical problems that need to calculate photon density distribution functions for the photon flow passing materials of different type. This flow can be described by a type of transport equations similar to the Boltzmann equation. Notwithstanding the huge number of equation types depending upon the particularities of the photon-matter interactions, the main properties of their trajectories are similar. Therefore it is possible to find a generalized model description for the photon trajectories which can be used to solve a large number of other problems.</p

Computer Simulation of X-Ray NDE Process Coupled with CAD Interface

Tools for computer simulation are helpful in NDE manyfold. A global conception of reliability in NDE can include among other procedures performance prediction by computer simulation. POD data of simulated defects can be calculated. Computer simulation gives the possibilities to optimize testing parameters, to make feasibility analysis for special testing problems, and to support the interpretation of testing results especially in case of complex component geometry. In this way simulation tools are valuable for planning and for evaluating of the examinations.</p