Hamamatsu has developed a range of sealed microfocus X-ray sources for non-destructive inspection. The smallest spot size that can be obtained with the 150 kV L8121-03 is 5 micron and the L8321-01 offers a spot size of <1 micron.  These provide sharp images even at maximum magnification. There are many sources which are hermetically sealed and air cooled and feature RS-232C interface for external control. Most of the units contain both the high voltage power supply and air cooled, sealed X-ray tube in one package, for simple operation. Microfocus sources with open tubes that permit changing of the cathode are also available. Applications include IC and PC inspection and critical parts inspection such as turbine blades for small cracks.