Specifications include, but are not limited to: The instrument being purchased is an electron probe micro-analyzer (EPMA). This instrument is capable of quantitative, nondestructive, in-situ chemical analysis on the scale of micrometers or less, and of imaging samples by a variety of means that result from exposure of the sample to a controlled electron beam. Thus, the instrument in question has a controllable (voltage, current) electron source, a focusing system (lenses) which allows user control of focal length (beam size) and scanning parameters, and an array of detectors for assessing and quantitatively measuring X-ray intensities and displaying backscattered and secondary electron emission from the sample. Specific characteristics for this purchase are listed as follows: A. Vacuum system must be dry technology, ion pump on gun chamber, magnetically levitated turbomolecular high vacuum pump on sample chamber and column, dry scroll (or equivalent) roughing/backing mechanical pump(s). B. Automated vacuum system with airlock for sample exchange, this will include an ion pump at the gun chamber, and dry scroll (or other dry technology) roughing/backing mechanical pump(s) to minimize hydrocarbon contamination. C. Sample chamber vacuum nominally 5 E -5 Pa or better D. Electron gun chamber must be isolatable from the sample chamber during sample exchange, and nominally 5E -6 Pa or better. E. System venting must be isolatable, and must have an option to vent with dry nitrogen. F. Sample chamber isolated by windows from spectrometer vacuum to maintain low sample chamber pressure and keep contaminants that evolve from sample during beam exposure from contaminating monochromators. G. LaB6/CeB6 electron source, switchable with tungsten. A number of applications set forth in the proposal rely heavily on routine high current work, therefore high current performance is particularly important. However, other applications involving beam sensitive materials requires excellent performance at low current (below 5 nA) also. H. Nominal cathode (LaB6/CeB6) lifetime should exceed 22000 hrs. at full temperature. I. High current beam regulation (up to 1.0 microamp) and total current range up to 10 microamps. Regulated current should be stable to at least 0.05% per hour at 15kV, 200nA. J. The beam current measurement system must maintain linearity through the entire measurement range, such that dead-time corrected intensities for a single X-ray measurement (for example, the SiKa line on quartz) must remain constant (within 0.5%) through the range of current up to 1.0 microamp. Automatically implemented software linearization is acceptable. K. Beam position must not vary more than 0.5 micrometers per hour at 15kV, 200nA, including during active spectrometer motion during analysis. L. Automatic beam current, voltage, and diameter settings, changeable based on point by point requirements. M. Sample stage must accept split shuttle wherein a set of standards can remain in the machine on a semi-permanent basis. N. The sample stage motion must be movable to at least 0.1 micrometer increments, and reposition on automation to within at least 1.0 micrometer. Reproducibility uncertainly must not be cumulative. O. Zoom light optical system for reflected light observation and stage focusing. This should be true optical zoom (as opposed to purely digital zoom) to maintain pixel resolution. The optical image must be digitally exportable.