Continuous X-rays produced in light-ion–atom collisions

Continuous X-rays produced in light-ion–atom collisions producing continuous backgrounds and therefore determining the detection limit of PIXE, have been experimentally and theoretically studied. It is shown that the experimental results over the wide range of projectile-ion energy from 0.5 to 40 MeV are well explained by four sources of radiative processes: nuclear bremsstrahlung (NB), atomic bremsstrahlung (AB) (or polarization bremsstrahlung), secondary-electron bremsstrahlung (SEB), and quasi-free-electron bremsstrahlung (QFEB).