New applications and extensions of the unique advantages of HVEM for physical and materials research

A report is given of the great progress made in HVEM since 1971. It is found that the number of instruments in operation has increased considerably, the resolution of current models has exceeded practical, if not theoretical, expectations, some in-situ studies have been rather successful, several high voltage STEMs are in operation and advances have been made in understanding electron-specimen interactions and image formation - especially at high resolution. Much less progress has been made in producing superior photographic materials and video image recording devices, in assessing the importance of radiation damage in both high-resolution studies and in-situ experiments and in resolving questions as to the merits of HVSTEM vs. HVCTEM. (C.F.)