Semper

Semper is a set of software programs originaly developed in Cambridge in the U.K. for simulation and manipulation of electron microscope images. In various forms it is present in many electron microscope laboratories around the world. It is possible to expand the capabilities of Semper using either library routines or additional commands; some of ours are Public Domain.

The particular version of Semper used at Northwestern is interfaced both to on-line image acquisition software and the multislice software using the NUMIS system. We can use this to directly acquire 512x512 images from the microscope, although we prefer to use a microdensitometer and scan in the whole negative.

As a simple example, shown below are simulations of amorphous carbon images and power spectra for a series of defoci both without and with 10nm of astigmatism, for conditions representative of the H-9000 at Northwestern.

Amorphous carbon images at different defoci

Amorphous carbon power-spectra at different defoci

Amorphous carbon images at different defoci with 10nm astigmatism

Amorphous carbon power-spectra at different defoci with 10nm astigmatism

Other sites using Semper

Synoptics Address

Lycos search: semper

Signal and Image Processing Group

Steve Bagley's page (being developed)

Mid-Ocean Ridge Processes: Research (Computer may be down)

UM-StL Scanned Tip and Electron Image Lab