Monte Carlo simulation of x-ray generation and energy dissipation in a W/Cu target for optimum design of a high-power x-ray source

摘要

Monte Carlo simulation of x-ray generation by electron impact was applied to a W/Cu target (tungsten W film on a copper substrate) to find the optimum conditions for a high-power x-ray source. To assess the performance of the high-power x-ray source, we propose using: (1) The total intensity of continuous x-rays emitted from the target, I-t0 = integral(lambdamin)(infinity) i(t0) (lambda)dlambda, where i(t0) (lambda) is a X-in spectrum of continuous x-rays emitted from the target under bombardment of an electron beam of primary energy E-0. (2) The cooling efficiency of the W/Cu target, which is gammaE(0) = sigma(Cu) . integral(DeltaW)(infinity)(dE/dz)(Cu) dz/[sigma(Cu).integral(DeltaW)(infinity)(dE/dz)(Cu) dz + sigmaw . integral(0)(DeltaW) (dE/dz)(W)dz] where (dE/dz)(j) and sigma(j) are the in-depth energy dissipation in a target of element j and the thermal conductivity of element j, respectively, in the W/Cu target with tungsten film thickness ATV. Both I-E0 and gamma(E0) were obtained from Monte Carlo calculations for different tungsten film thicknesses by varying the incidence angle of the electron beam and the take-off angle of the x-rays according to the primary energy levels of the electron beam. Copyright (C) 2002 John Wiley Sons, Ltd. [References: 15]