XRF中激发电位和靶材对散射效应增强荧光强度的影响研究

采用一组熔融片样品研究了由不同的X光管激发电位和不同的X光管靶材(Cr靶和Rh靶)所导致的入射X射线能量及强度分布变化对3种散射效应增强荧光强度的影响规律.研究的散射增强包括相干散射激发的荧光强度、非相干散射激发的荧光强度以及其他方向的一次荧光被散射进探测方向的强度.研究结果表明,对于采用的熔融片,相干散射效应和一次荧光被散射进探测器方向增强效应对荧光强度的贡献随X光管激发电位增大而减小,用Cr靶原级谱激发比用Rh靶原级谱激发贡献大;而非相干散射效应对荧光强度的贡献则随X光管激发电位增大而增大,用Rh靶原级谱激发比用Cr靶原级谱激发贡献大;3种散射效应对荧光强度的总贡献随X光管激发电位增大而增大,在Rh靶原级谱激发条件下比用Cr靶原级谱激发贡献大.

Study on the Influence of Excitation Voltage and Anode on the Contribution of Scattering Effects to the Intensity of X-Ray Fluorescence

The influence of X-ray tube spectral distribution related to the X-ray tube voltage and target anode on the contribution of scattering effects to the intensity of fluorescence was studied by using some fused disk samples. Three scattering effects were considered. They are coherent scattering effect, incoherent scattering effect and primary fluorescence scattered into the direction of detector respectively. For the fused beads under investigation, the results show that the contributions of coherent scattering effect and the primary fluorescence scattered into the direction of detector decreased with increasing the tube voltage, and the contribution was larger when excited by the X-ray from Cr target than that from Rh target. On the contrary, the contribution of incoherent scattering effect to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target. The sum of the contribution of scattering effects to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target.