This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. ABSTRACT: The IVEM (JEOL JEM-4000FX) is primarily used for TRD1, electron tomography of frozen- hydrated specimens. The IVEM is equipped with a LaB6 cathode, a 5-axis computer-controlled goniometer, and several double-tilt and tilt-rotation specimen stages, as well as Gatan single-tilt and tilt-rotation cryo-transfer stages. In 2002, we completed installation of a Gatan GIF2002 post-column energy filter equipped with a 2048x2048 CCD camera, and a TVIPS FastScan TV-rate CCD camera was installed for tracking beam-sensitive specimens at very low electron dose. Automated electron tomography is provided via external computer control. The instrumental resolution is 0.14 nm (gold lattice). The STEM-mode point-to-point resolution is 1 nm. Full analytical capability is provided, including EELS and EDX. Activity in past reporting period: The aging Emispec ES Vision STEM imaging and EDX/EELS spectroscopy system was replaced with a 4pi """"""""Revolution"""""""" system. This was necessary because Emispec no longer exists, and service on the units is no longer available. We took this opportunity to consolidate all EM control software on a new, single computer. We installed the latest versions of the Gatan and Tietz imaging software. We re-wrote our automation system for collecting tomographic tilt-series images, since the old version was built on the Emispec system. The new version is completely stand-alone. It has a much easier-to-use interface with the Gatan energy filter and CCD imaging, via internal direct commands to Gatan Digital Micrograph. All EM control and imaging can now be done from the same application window, and the number of mouse needed for data collection has been reduced. The new software was written by Dean Leith. It was necessary to do this, rather than simply implementing Serial EM or another more-modern data-collection system, because the specimen stage of the JEM-4000 is not as eucentric as that of more modern TEMs, requiring a more-complicated procedure to track the specimen during the tilt series. The integration of STEM spectrum imaging for both electron energy-loss and energy-dispersive x-ray microanalysis, is now done using the Revolution system supplied by 4pi company. The President of 4pi, Scott Davilla, is a former Resource staff member, having worked on our HVEM. We are a beta-test site for integration of EELS with STEM, and we will use this system with our new JEM-3200FSC during the next funding cycle (see below).
Showing the most recent 10 out of 252 publications
