This blog post includes a video that demonstrates the area of illumination for a PHI 04-548 dual anode X-ray source. That is, where the X-rays hit the sample.

The 04-548 dual anode source typically has one anode side that is Mg and the other side is Al. The older XPS systems that have an 04-548 X-ray source use a lens on the input to the SCA (Spherical Capacitor Analyzer) which determines the analysis area. For example the PHI 5600 XPS system can analyze areas as large as 10mm X 4mm down to 75uM.

The actual illumination area of the 04-548 dual anode X-ray source is quite large as shown in this video – 04-548 X-ray source illumination area.

Today’s state of the art XPS systems focus a small electron beam onto an aluminum target in conjunction with a mono-chromator to excite a very small area on the sample. Rather than exciting a very large area, today’s XPS systems excite a very small area. Down to just a few microns which make it possible to image the sample and analyze surface defects.