(Supported by the NIH/NCRR/P41 RR 01219 grant). The HVEM website compliments the mailed-in grid program, and otherwise promotes the availability of the instrument. The website provides immediate access to images on the HVEM, feedback between the remote user and the microscope operator, and methods to survey specimen remotely. The website does not provide the remote control of the microscope, which we do not anticipate will be necessary for most users. For televiewing, we use a lens-coupled, intensified, TV-rate CCD camera which was developed in-house for low-dose viewing, focusing, and image capture. The quality of these images is good, approximately 640x480 pixels, which depends mainly on the phosphor screen used for image conversion from electrons to light. We developed a particle-size filtering method to make phosphor screens with very good uniformity and resolution, taking into account the trade-off between sensitivity and resolution. We consulted with Dr. Nestor Z aluzec of Agronne National Lab, Dr. Larry Allard of Oak Ridge National lab and Dr. Mark Ellisman of U. San Diego, concerning approaches to and problems with tele-microscopy, and which computer systems and software are most suitable. A PowerMac clone with video capture board was acquired, Mac webserver software was downloaded, and a dedicated web server with video-streaming capability was set up. A webpage accessible to anyone with a standard web browser was created. Images of 320x320 pixels can be updated at a rate of about one per second, or higher-resolution images can be provided at a slower rate. An auxiliary camera can be selected for a view of the operator, for example. We plan to add specimen-position coordinate readout facility to the HVEM stage controller, which will interface with the televiewing system. The location of the HVEM website is: www.wadsworth.org/spider_doc/bmirr/hvem/index.html
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