Problem definition:
The Navy Prototype Optical Interferometer, located just outside Flagstaff, Arizona, has a prototype Big Beam Compressor (BBC) designed to compress and recollimate a beam of light collected from a 20 inch siderostat into a 5 inch beam which can be transported in the vacuum line feeds on the array. Currently, experimental tests show that the prototype has a very low fundamental frequency of 17 Hz which is well within the range of inherent vibrations at the Flagstaff site. Previous Finite Element Analysis (FEA) studies have shown that it is possible to increase the fundamental frequency from 17 Hz to 128 Hz with the addition of structural members. An increase toward this frequency would allow the beam compressor to be out of the range of most inherent vibrations at the site as well as reduce the amplitude of these vibrations. This would allow further testing and additional enhancements toward the installation and commissioning of the beam compressor. This would effectively increase the viewable stars from 7,000 to 70,000. In order to verify the FEA, specified structural members are to be manufactured and installed on the beam compressor. Testing and verification will then be carried out through the use of Endevco Isotron accelerometers.
NPOI Capstone team will provide:
• Additional stability structure analysis
• The constructing of stabilizing members
• Modify secondary mirror mount
NPOI will provide:
• Access to the NPOI facilities and the beam compressor at NAU
• Former FEA/Capstone results
• Funding for any materials needed for completion of project