Bombardments of iron (commercially pure) with self-ions having energies of 50 and 100 keV were performed in–situ in a High–Voltage Electron Microscope at temperatures of 40 and 300 K. The resulting damage microstructures were examined at the irradiation temperature in the HVEM using 200, 300, 500 and 1000 keV electrons (damage threshold in Fe is ∼330 keV). Dislocation loop densities were measured as functions of ion dose, ion energy, irradiation temperature, electron dose (500 keV), and step annealing to room temperature. Loop geometries, size distributions, and nature (interstitial or vacancy) were also determined.

Atherosclerotic lesions of the thoracic aorta and particularly mobile mural thrombi constitute a rare but important source of cerebral and peripheral emboli. Conventional treatment of such pathologies includes systematic anticoagulation therapy and surgical thromboendarterectomy, with potential segmental replacement of the thoracic aorta using synthetic grafts. We report the successful covering of a mobile thoracic aortic thrombus using a commercially available endograft (Endofit) in a patient presented with multiple peripheral emboli. The endovascular treatment of such lesions constitutes a new alternative treatment particularly effective and safe that decreases considerably both operational time and surgical risk.

Direct observations in the high voltage electron microscope of electron- and ion-beam-induced effects in solids now form a significant part of the research activity at the Argonne National Laboratory High Voltage Electron Microscope Tandem Facility. The programs utilize unique facilities that permit samples held at temperatures between 10 and 1300 K to be bombarded in vacuo with ions having energies between 20 keV and 8 MeV. Instrumentation both internal and external to the high voltage electron microscope has been provided to characterize fully the ion beam at the specimen rod over a wide range of beam intensities.

The use of analytical and high-voltage electron microscopies (AEM, HVEM) for microcharacterization is now well established as a powerful tool in both basic and applied materials research. There are, however, several fundamental limitations in the use of analytical electron microscopy in lower voltage instruments (100 to 200 kV) which restricts microanalysis - most notably multiple scattering. As a result of this, there is sufficient motivation to explore the merits of AEM-type microanalysis in the HVEM regime. This paper will discuss aspects of both qualitative and quantitative analysis at higher voltages, as well as the plans for upgrading the ANL 1.2 MeV HVEM (EM-7) for x-ray and electron-energy-loss spectroscopies (XEDS, EELS).

Recent work has shown that ion implantation is a powerful scientific and technological tool in surface metallurgy. In order to study in situ effects of ion implantation/bombardment on the structure of materials, we have constructed an ion-beam interface system to deliver a fully characterized beam of ions into the specimen stage of the Argonne National Laboratory 1.2 MV high voltage electron microscope at an angle of 33° to the microscope axis. The facility has two accelerators. A 300 kV modified Texas Nuclear with a sputter ion source, and a National Electrostatics Universal 2 MV Tandem accelerator model 2UDHS which is scheduled for operation this fall. The microscope is equipped with a number of specialized stages to permit observations to be made between 78–1100 K with double tilt capability, and from 10–1300 K wth single tilt. A single tilt, heating, tensile stage is also available. Although the system design indicates a minimum beam envelope of 0.2 mm diameter in the microscope, initial experimental work has used beam diameters of 1–2 mm to bypass problems of introducing spatial stabilizers into the ion beam. The ion beam used in the following studies are: (N+, Si+, Ni+) is restructing of Ni-12.8% Si; (Li+) in oxidation of nickel; and (Fe+) in implant structures in Al.