Numerical analysis of spectrum degradation methods of pulsed hard X-ray

Spectrum degradation methods of pulsed hard X-ray by optimum design of bremsstrahlung converter were introduced based on bremsstrahlung principal. Output parameters of composite converter and reflection converter were simulated by using MCNP code. Influence of converter thickness on spectrum, conversion efficiency of X ray and transmission electron quota was analyzed. The difference of spectrum and conversion efficiency between transmission and reflection X-ray of reflection converter and the change law of these parameters according to electron incidence angle were presented. Experiments of two converters with different thickness were carried out, and the experimental result is close to simulation result. These methods can be used to degrade spectrum of pulsed hard X-ray. (authors)