DIRS Laboratory 76-3215
November 2, 2018 at 9:00am
ANTON TRAVINSKY
Ph.D. Thesis Defense
Abstract: 

Multi-object spectrometers (MOSs) are extremely useful astronomical instruments that allow for spectral observations of up to several thousands of objects simultaneously by using an object input selector commonly referred to as slit mask. Studies performed with such instruments in the last three decades placed unique constraints on cosmology, large scale structure, galaxy evolution, and Galactic structure. Terrestrial MOSs use large discrete components for object selection, which, aside from not being transferable to space-based applications, are limited in both minimal slit width and minimal time required to reconfigure the slit mask to a new field of objects. There is a pressing need in remotely addressable and fast-re-configurable slit masks for allowing space-based instruments with MOS capabilities. Digital micromirror devices (DMDs) can be viable candidates for the role of remotely re-configurable slit mask in both terrestrial and space-based MOSs. These devices were originally developed by Texas Instruments (TI) for projection systems and are the core part of the TI digital light processing (DLP) technology. This work focused on assessing the suitability of DMDs to be used as slit masks in space-based astronomical MOSs. The results of typical pre-launch tests such as radiation testing, vibration testing, and mechanical shock testing suggest that commercially available DMDs are mechanically suitable for space-deployment. Series of tests to assess the performance and the behaviour of DMDs in cryogenic temperatures (down to 70 K) did not identify any problems with subjecting commercially available DMDs to such temperatures for extended periods of time. An early prototype of terrestrial DMD-based MOS (Rochester Institute of Technology Multi Object Spectrometer-RITMOS) was updated with a newer DMD model and tested through two deployments at the CEK Mees observatory in Naples, NY. The results of all experiments strongly suggest that DMDs are well-positioned to serve as slit masks in terrestrial MOS and to enable a new generation of space-based instruments - with MOS capabilities.