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High resolution solar observations from first principles to applications

Posted on:2010-12-07Degree:Ph.DType:Dissertation
University:New Jersey Institute of TechnologyCandidate:Verdoni, Angelo PFull Text:PDF
GTID:1442390002474513Subject:Physics
Abstract/Summary:
The expression "high-resolution observations" in Solar Physics refers to the spatial, temporal and spectral domains in their entirety. High-resolution observations of solar fine structure are a necessity to answer many of the intriguing questions related to solar activity. However, a researcher building instruments for high-resolution observations has to cope with the fact that these three domains often have diametrically opposed boundary conditions. Many factors have to be considered in the design of a successful instrument. Modern post-focus instruments are more closely linked with the solar telescopes that they serve than in past. In principle, the quest for high-resolution observations already starts with the selection of the observatory site.;The site survey of the Advanced Technology Solar Telescope (ATST) under the stewardship of the National Solar Observatory (NSO) has identified Big Bear Solar Observatory (BBSO) as one of the best sites for solar observations. In a first step, the seeing characteristics at BBSO based on the data collected for the ATST site survey are described. The analysis will aid in the scheduling of high-resolution observations at BBSO as well as provide useful information concerning the design and implementation of a thermal control system for the New Solar Telescope (NST). NST is an off-axis open-structure Gregorian-style telescope with a 1.6 m aperture. NST will be housed in a newly constructed 5/8-sphere ventilated dome. With optics exposed to the surrounding air, NST's open-structure design makes it particularly vulnerable to the effects of enclosure-related seeing. In an effort to mitigate these effects, the initial design of a thermal control system for the NST dome is presented. The goal is to remediate thermal related seeing effects present within the dome interior. The THermal Control System (THCS) is an essential component for the open-telescope design of NST to work. Following these tasks, a calibration routine for the polarization optics for the Visible-light Imaging Magnetograph (VIM) is presented. VIM uses a set of two Liquid Crystal Variable Retarders (LCVRs) as the main components of its Stokes analyzer. Calibration of these components is a crucial step in providing reliable polarimetric measurements of the Sun using VIM. On 2007 July 15, using the Dunn Solar Telescope (DST) at the National Solar Observatory at Sacramento Peak (NSO/SP), New Mexico, the first polarimetric measurements using VIM were made. As a final step, illustrating an application of high-resolution solar observations, the results of a two-dimensional time-series acquired on 2006 June 11, using the DST at NSOP is presented. The data is used in a study of upflow events that are observed to occur in the Hα 656.3 nm and Na D2 589.0 nm chromospheric absorption lines.
Keywords/Search Tags:Solar, Observations, Thermal control system, NST, First, VIM
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