The experimental measurement of electron-impact K-shell ionization cross sections of Cu and Co elements within the energy region 8-25 keV was reported. The influence of a substrate of thin targets on ionization cross sections has been corrected by a method based upon a bipartition model of electron transport ͓Z. M. Luo, Phys. Rev. B 32, 812 ͑1985͒; 32, 824 ͑1985͔͒. The measured cross sections are in good agreement with existing data and are well reproduced by the empirical formula of Green and Cosslett ͓Proc. Phys. Soc. London 78, 1206

Radiation damage in quartz has been of interest to the semiconductor industry, optical fiber industry, and nuclear industry. Cross-section transmission electron microscopy (TEM) is a powerful tool for investigating the irradiation effects since it provides a direct measurement of the ion and the damage distributions, and can also provide detailed microstructural information such as the presence of amorphous regions and the size, density and chemical nature of defect aggregates. The results reported below are from a systematic cross-section TEM study on 1.5 MeV Kr+ ion irradiated quartz.3-mm discs of quartz (along 010 face) were prepared with 100 μm in thickness. One side for each discs was well polished using a 0.05 μm diamond paste. The well-polished side was irradiated at room temperature with 1.5 MeV Kr ions in the HVEM-Tandem Facility at Argonne National Laboratory. Following irradiation, cross-section TEM specimens were prepared using the so-called T-tool technique, a modified tripot technique