Focused beam total reflection X-ray fluorescence with low power sources coupled to doubly curved crystal optics

A focused beam total X-ray fluorescence technique was developed based on doubly curved crystal optics. This technique provides good detection sensitivity and spatial resolution for localized detection of surface deposits. Compact low power X-ray sources were used to demonstrate the benefit of the X-ray optics for focusing Cr Kα, Cu Kα and Mo Kα radiation. The detection capability of the focused beam Total reflection X-ray fluorescence system was investigated with dried droplets of calibrated low concentration solutions. Detection limits at the femtogram level were demonstrated.