Design and performance of a laboratory based source of characteristic x-rays

A theoretical description for the production of characteristic X-rays (CX) is reviewed highlighting features that enhance the CX intensity. These are incorporated into the design of a secondary target system for excitation by white radiation produced by an industrial X-ray tube; Philips MCN-166, capable of continuous operation at up to 160 kVp and 1.6 kW. Results are presented for the measured spatial profile, CX intensity at 8-75 keV and spectral purity as a function of accelerating voltage. The beam is a narrow fan with half height (horizontal by vertical) 200 mm by 50 mm at 1 m from the source. The beam intensity is presented in units ph/s/mm2 at 1 m per kW and is equivalent to an isotope source with activities 100-300 mCi per kW deposited in the anode. The source provides variable intensity and the ability to change energy by simply exchanging the target material.