Matching Items (5)
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- All Subjects: optics
Description
The Star Planet Activity Research CubeSat (SPARCS) will be a 6U CubeSat devoted to photometric monitoring of M dwarfs in the far-ultraviolet (FUV) and near-ultraviolet (NUV) (160 and 280 nm respectively), measuring the time-dependent spectral slope, intensity and evolution of M dwarf stellar UV radiation. The delta-doped detectors baselined for SPARCS have demonstrated more than five times the in-band quantum efficiency of the detectors of GALEX. Given that red:UV photon emission from cool, low-mass stars can be million:one, UV observation of thes stars are susceptible to red light contamination. In addition to the high efficiency delta-doped detectors, SPARCS will include red-rejection filters to help minimize red leak. Even so, careful red-rejection and photometric calibration is needed. As was done for GALEX, white dwarfs are used for photometric calibration in the UV. We find that the use of white dwarfs to calibrate the observations of red stars leads to significant errors in the reported flux, due to the differences in white dwarf and red dwarf spectra. Here we discuss the planned SPARCS calibration model and the color correction, and demonstrate the importance of this correction when recording UV measurements of M stars taken by SPARCS.
ContributorsOsby, Ella (Author) / Shkolnik, Evgenya (Thesis director) / Ardila, David (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Balloon-borne telescopes are an economic alternative to scientists seeking to study light compared to other ground- and space-based alternatives, such as the Keck Observatory and the Hubble Space Telescope. One such balloon-borne telescope is the Balloon-borne Large Aperture Submillimeter Telescope, or simply BLAST. Arizona State University was tasked with assembling one of the primary optics plates for the telescope's next mission. This plate, detailed in the following paragraphs, is designed to detect and capture submillimeter wavelength light. This will help scientists understand the formation and early life of stars. Due to its highly sensitive nature detecting light, the optics plate had to be carefully assembled following a strict assembly and testing procedure. Initially, error tolerances for the mirrors and plate were developed using a computer model, later to be compared to measured values. The engineering decisions made throughout the process pertained to every aspect of the plate, from ensuring the compliance of the engineering drawings to the polishing of the mirrors for testing. The assembly procedure itself was verified at the conclusion using a coordinate measuring machine (CMM) to analyze whether or not the plate was within defined error tolerances mentioned above. This data was further visualized within the document to show that the assembly procedure of the BLAST optics plate was successful. The largest error margins seen were approximately one order of magnitude lower than their tolerated limits, reflecting good engineering judgement and care applied to the manufacturing process. The plate has since been shipped offsite to continue testing and the assembly team is confident it will perform well within expected parameters.
ContributorsDombrowski, Shane Matthew (Author) / Groppi, Christopher (Thesis director) / Mauskopf, Philip (Committee member) / Underhill, Matthew (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The following paper discusses the validation of the TolTEC optical design along with a progress report regarding the design of the optical mounting system. Solidworks and Zemax were used in conjunction to model the proposed optics designs. The final optical design was selected through extensive CAD modeling and testing within the Large Millimeter Telescope receiver room. The TolTEC optics can be divided into two arrays, one comprised of the warm mirrors and the second, cryogenically-operated cold mirrors. To ensure structural stability and optical performance, the mechanical design of these systems places a heavy emphasis on rigidity. This is done using a variety of design techniques that restrict motion along the necessary degrees of freedom and maximize moment of inertia while minimizing weight. Work will resume on this project in the Fall 2017 semester.
ContributorsKelso, Rhys Partain (Author) / Mauskopf, Philip (Thesis director) / Groppi, Christopher (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
TolTEC is a three-band millimeter-wave, imaging polarimeter installed on the 50 m diameter Large Millimeter Telescope (LMT) in Mexico. This camera simultaneously images the focal plane at three wavebands centered at 1.1 mm (270 GHz), 1.4 mm (214 GHz), and 2.0 mm (150 GHz). TolTEC combines polarization-sensitive kinetic inductance detectors (KIDs) with the LMT to produce high resolution images of the sky in both total intensity and polarization. I present an overview of the TolTEC camera’s optical system and my contributions to the optomechanical design and characterization of the instrument. As part of my work with TolTEC, I designed the mounting structures for the cold optics within the cryostat accounting for thermal contraction to ensure the silicon lenses do not fracture when cooled. I also designed the large warm optics that re-image the light from the telescope, requiring me to perform static and vibration analyses to ensure the mounts correctly supported the mirrors. I discuss the various methods used to align the optics and the cryostat in the telescope. I discuss the Zemax optical model of TolTEC and compare it with measurements of the instrument to help with characterization. Finally, I present the results of stacking galaxies on data from the Atacama Cosmology Telescope (ACT) to measure the Sunyaev-Zel’dovich (SZ) effect and estimate the thermal energy in the gas around high red-shift, quiescent galaxies as an example of science that could be done with TolTEC data. Since the camera combines high angular resolution with images at three wavelengths near distinct SZ features, TolTEC will provide precise measurements to learn more about these types of galaxies.
ContributorsLunde, Emily Louise (Author) / Mauskopf, Philip (Thesis advisor) / Groppi, Christopher (Committee member) / Scannapieco, Evan (Committee member) / Noble, Allison (Committee member) / Bryan, Sean (Committee member) / Arizona State University (Publisher)
Created2023
Description
This dissertation explores the design, testing, and implementation of cutting-edge spaceborne instrumentation through the investigation of three distinct projects: SPARCS, STRUVE, and EXCITE. The SPARCS astrophysics project focuses on the development of a thermal vacuum chamber for testing contamination-sensitive hardware, alongside the design of ground support equipment (GSE) tailored to SPARCS' performance requirements. STRUVE, a heliophysics CubeSat mission concept, is examined for its mechanical and thermal design strategies, as well as thermal sensitivity studies crucial for mission success. The EXCITE project, an infrared spectrometer balloon-based astrophysics mission, is analyzed for its opto-mechanical design and comprehensive coefficient of thermal expansion (CTE) stress analysis. Throughout the dissertation, each project's challenges, innovations, and solutions are meticulously documented, providing insights into the intricacies and demands of space instrumentation design and testing. The introduction sets the stage by contextualizing the significance of spaceborne instrumentation projects and outlining the scope of the dissertation. The chapters present detailed examinations of SPARCS, STRUVE, and EXCITE, and discuss the engineering complexities and advancements achieved in each project. In conclusion, the dissertation reflects on the lessons learned, implications for future space missions, and the broader impact of SPARCS, STRUVE, and EXCITE on the field of spaceborne instrumentation. This research contributes to the ongoing discourse surrounding space technology innovation and underscores the importance of interdisciplinary collaboration in pushing the boundaries of space exploration.
ContributorsGamaunt, Johnathan (Author) / Scowen, Paul (Thesis advisor) / Butler, Nathaniel (Thesis advisor) / de Wijn, Alfred (Committee member) / Groppi, Christopher (Committee member) / Jacobs, Daniel (Committee member) / Arizona State University (Publisher)
Created2024