We have developed a process that is able to detect, count, and map micropipes on SiC substrates. This process uses a polarized light microscope to scan the wafer. The pictures taken are analyzed with a program that produces a micropipe map as well as numerical defect distribution data in a text file. The results of the process were validated with x-ray topography measurement. The repeatability of this process is also studied and reported.
Stable beam alignment of an optical interferometer is crucial for maintaining a usable signal-to-noise ratio during science measurements on faint astronomical targets. The Magdalena Ridge Observatory Interferometer will use an Automated Alignment System (AAS) that performs a start-of-night alignment procedure and subsequent alignment corrections in between observations, all without the need for human intervention. Its design has recently been updated in line with a revised error budget for MROI requiring that two axis drifts during science operations should not exceed 15 milliarcseconds in tilt, referred to the sky, nor 1% of the beam diameter in shear. For each beam line, the AAS provides two reference light beams, a pair of quad cells to monitor coarse alignment, and a tilt and shear detector for tracking fine drifts. The tilt and shear detector is a novel application of a Shack-Hartmann array that permits the simultaneous measurement tilt and shear well within requirements for MROI. Results of laboratory testing and simulations are presented here.
The Magdalena Ridge Observatory Interferometer (MROI) software system contains distributed systems managed by a centralized Supervisory System. Interface software is generated from spreadsheets that describe commands, monitor points, and fault conditions for each subsystem. The Supervisory System consists of an Executive, Operator, Database Manager; one or more Supervisors plus Fault Manager, and Data Collectors. System-wide simulations are discussed: (1) a test framework is generated from the spreadsheets characterizing a subsystem; (2) a detailed simulation of the actual hardware in a subsystem; (3) a system-wide simulation of collecting astronomical data based on executing observing projects. The first two levels have been implemented.
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