PIXE studies on pure metal targets surrounded by insulating material produc
ed enhanced X-ray yields at comparatively low proton energies. Specially pr
epared metal discs of selected transition elements were embedded in Macer t
arget holders and irradiated with 700 keV protons. Improved X-ray yields of
up to more than 300% were observed. It was found that the enhanced yields
were affected by the incident beam current due to a "leakage" effect. The r
ecorded time-dependent spectra showed similar charge build-up and discharge
patterns as those originally obtained for non-conducting samples. A possib
le mechanism for the enhancement is discussed.