A Monte Carlo model was used to simulate specimen-electron beam interactions relevant to electron back-scattered diffraction (EBSD). Electron trajectories were calculated for a variety of likely experimental conditions to examine the interaction volume of the incident electrons as well as that of the subset of incident electrons that emerge from the specimen, i.e., back-scattered electrons (BSEs). The spatial resolution of EBSD was investigated as functions of both materials properties, such as atomic number, atomic weight, and density, and experimental parameters, such as specimen thickness, tilt, and incident beam accelerating voltage. These simulations reveal that the achievable spatial resolution in EBSD is determined by these intrinsic and extrinsic parameters.

Electron beam damage is a significant limitation for transmission electron microscopy (TEM) studies of beam-sensitive samples. An approach for studying surface reactions on alkali halide crystals using 200 kV TEM is presented. Experiments were designed to monitor the reaction of NaCl crystals with HNO3 gas followed by water vapor to form solid NaNO3. During beam damage experiments, TEM micrographs record structural changes to both NaCl and NaNO3, including dislocation loops, void formation, and decomposition. Sample decomposition can be successfully minimized by a combination of commonly used techniques: (1) focusing the beam adjacent to the area of interest, (2) lowering the electron density, (3) choosing to image larger (micrometer- versus submicrometer-sized) alkali halide crystals, and (4) lowering temperature by the use of a liquid nitrogen cooling stage. From these results, additional studies were designed that monitored sequential experiments. Sensitive micrometer-sized sodium chloride single crystals before and after exposure to nitric acid vapor and water vapor and the subsequent growth of submicrometer-sized sodium nitrate single crystals could then be successfully imaged using TEM.

The performance characteristics of electron microscopes and probe-forming instruments depend ultimately on the focal properties and aberrations of electron lenses. A practical method of experimentally determining the properties of electron lenses is described. The method utilizes shadows cast by two meshes inserted separately in front of the lens and behind the lens to study the properties of the image of a point source. The image properties are then used to calculate the lens properties. The paraxial values of the focal length and focal distance as well as their spherical and chromatic aberrations are determined. Experimental data and the analysis are presented in the form of a tutorial that has been tested in the classroom. Discussions of the relationship between image properties and lens properties, in particular, focal point aberrations and focal length aberrations, and the various ways aberration coefficients can be defined, are included to clarify concepts in optics that are important for microscopists.

Light microscopy was used to analyze the effects of added catalyst at different conditions (temperature and reaction times) in liquefaction testing of a low pyritic sulfur bituminous coal. Quantitative changes in vitrinite/vitroplast reflectance of coal and liquefaction residues were shown to be useful markers in analyzing and understanding the role of catalyst during the initial stage of coal particle hydrogenation. Lower reflectance values corresponded to increased conversions up to about the 60 min and 375°C experimental conditions. Microscopical observation of liquefaction residues also revealed the presence of “wall scales” of varying width.

A laboratory test of X-ray tomography employing a diverging beam of X-rays rather than the usual parallel X-ray beam is described. We chose to test and demonstrate the advantages of divergent beam tomography by imaging an extracted juvenile human premolar using an ordinary dental X-ray source and a cooled CCD camera. Experiments with a three-piece cover-glass sample and with the human tooth demonstrated that three-dimensional reconstruction can be achieved at 34 μm per pixel resolution employing an X-ray tube spot 800 μm in its smallest direction without requiring close contact with the fluorescent screen. Reconstruction of a 256 x 256 pixel single-plane image from 100 projection images took only 45 sec on a personal computer with a Pentium 166 MHz processor. We have also demonstrated a volume reconstruction of 256 x 256 x 256 voxels from the data. Successful extension of this work to submicrometer projection X-ray microscopy is predicted. Improved resolution of medical tomography is another possible application.

Three-dimensional image formation in an interference confocal scanning microscope under ultra-short pulsed beam illumination is investigated in this study. The novelty of this new image system is that it keeps advantages in femtosecond interferometry but also provides a femtosecond-resolved three-dimensional image without necessarily using an ultrafast detector. For a 5-fs pulsed beam illumination, spatial resolution in the axial and transverse directions in this system is improved by approximately 45% and 15%, respectively, compared with that in the case of continuous wave illumination. However, strong chromatic aberration caused by an ultrashort pulsed beam can result in a degradation of spatial and temporal resolution, whereas weak chromatic aberration may lead to an improvement in transverse resolution.

We describe here a simple and inexpensive solution for marking film negatives with identification numbers before film development. This technique avoids the purchase of expensive camera-magazines with data-backs, and it reduces the risk of misidentifying film negatives.

It is with much pleasure and gratification that I encourage you to read the messages from the presidents of the five societies for whom Microscopy and Microanalysis is the official journal. Each of the five presidents graciously agreed to write a message for this first issue of 1998. Writing such messages is often a burden on an already overtaxed schedule and we very much appreciate the effort they all have made. These contributions reflect one of the primary goals of the News and Commentary, that is, to be an arena for contributions from all of the societies affiliated with the journal—contributions of interest to a broad spectrum of microscopists. We hope to truly make this journal an endeavor reflecting international exchange and cooperation. Again, I thank these presidents for taking the time to write these words. So please, respect this effort and take the time to read their comments. The five presidential messages are presented in the order of their listing on the front cover of the journal, which reflects the order in which the particular society became affiliated with Microscopy and Microanalysis.

Microscopy continues to be a rapidly evolving field. Advances in instrumentation and image processing/analysis in traditional areas of TEM, SEM, and micro-analysis have taken place in tandem with developments in force-based microscopy and light microscopic imaging systems. MSA, through its programs and publications, has been evolving as well to meet the challenges and opportunities these advances provide for investigators in both the biological and physical sciences.

As the new President of the Microscopical Society of Canada, I am aware that it is going to be difficult to follow in the footsteps of our past Presidents. A major concern, as with many societies, is the decline in membership; the MSC/SMC is no different.

Dear Colleagues,

As we move toward the twenty-first century, the Microbeam Analysis Society is going through a few changes, mostly for economic reasons. MAS is not a large society, yet it is healthy due to the strong support of members who believe that microanalysis needs its own venue for communication, education, and growth. I want to thank all those people who contributed to MAS, who through the years, from its beginnings more than thirty years ago to the present, have donated their time and energy to bringing the society to its mature position today. Thanks to these members, MAS exhibits the ultimate in scientific professionalism and fiscal integrity which makes me very proud to be a participant.

The Mexican Microscopy Society (MMS) wishes you all the best for 1998. One more year is over and the MMS has achieved its 1997 goals. Last year the MMS was very active collaborating in the organization of national and international conferences. Our presence was felt in several universities and colleges around our country through the organizing of courses and seminars which strongly supported the wide spread of knowledge and use of both electron and optical microscopies. Last but not least, we have also established strong ties with similar societies in all America.

This is the first time that the president of a Brazilian scientific society has addressed a message through Microscopy and Microanalysis. I would like to thank Barbara Reine, News and Commentary Editor, and Dale Johnson, Microscopy and Microanalysis Editor-in-Chief, for giving me the honor of this inaugural opportunity.

Joint meeting of the Microscopy Society of America (56th) and the Microbeam Analysis Society (32nd).

An exciting and diverse set of meeting activities has been arranged for the upcoming gathering of microscopists and micro-analysts in Atlanta, Georgia in July. The meeting should prove to have something for everybody. The core of the Microscopy and Microanalysis '98 meeting consists of state-of-the-art symposia in the areas of Advances in Instrumentation and Techniques and in Applications of Microscopy and Microanalysis in the areas of biological sciences and physical sciences. Invited speakers include world-renown researchers from 14 different countries. Of special interest are symposia celebrating 30 Years of Energy Dispersive Spectrometry in Microanalysis (specially sponsored by MAS), 30 Years of Atom Probe Field Ion Microscopy, and a pre-meeting workshop and meeting symposia on that topic have also been scheduled this year.

This list contains brief descriptions of each of the positions known to be open in Microscopy Society of America (MSA) Placement Office files as of January 1, 1998. Potential employers are urged to use the Placement Office as widely as possible to advertise their needs to MSA members. Likewise, MSA members who are seeking employment in microscopy are urged to register with the Office to receive data on open positions periodically.

E-mail messages regarding Microscopy and Microanalysis.

Following is a list of microscopy-related meetings and courses. The editors would greatly appreciate input to this list via the electronic submission form found in the MSA World-Wide Web page at http://www.msa.microscopy.com/. We will gladly add hypertext links to the notice on the Web and insert a listing of the meeting in the next issue of the Journal.