X-ray spectrum sampling technology in the CT projection simulation

A computer code was developed to simulate the operation of radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. However, in the process of projection simulation, we can’t use an expression to describe the distribution of the consecutive X-ray spectrum which is simulated by the Monte Carlo method. We only use numerical integration to realize the projection simulation. So in order to enhance the fidelity of the projection simulation, we research X-ray spectrum sampling technology, and propose projection simulation algorithm based on self-adaptive Simpson integration. The algorithm mainly uses self-adaptive Simpson integration to sampling, based on the distribution of the X-ray spectrum. Then realize the integration of the projection process. With simulation experiment and practical experiment, we have demonstrated that the new sampling method is not only more accurate but also very efficient. This new sampling method is expected to be very useful in X-ray projection simulation, as well as in computing similar sampling or integrals in other area.