Experimental and Monte Carlo simulated spectra of a liquid-metal-jet x-ray source

• The x-ray spectrum of a liquid-jet x-ray anode was measured with a CZT spectrometer.
• Results were compared with Monte Carlo simulations using MCNPX, PENELOPE, EGS5.
• Notable differences were found among the Monte Carlo simulated spectra.
• The key role was played by the electron-impact ionization cross-section model used.
• The experimentally measured spectrum was closely reproduced by the PENELOPE code.

A prototype x-ray system based on a liquid-metal-jet anode was evaluated within the framework of the LABSYNC project. The generated spectrum was measured using a CZT-based spectrometer and was compared with spectra simulated by three Monte Carlo codes: MCNPX, PENELOPE and EGS5. Notable differences in the simulated spectra were found. These are mainly attributable to differences in the models adopted for the electron-impact ionization cross section. The simulation that more closely reproduces the experimentally measured spectrum was provided by PENELOPE.