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Articles 1 - 14 of 14

Full-Text Articles in Astrophysics and Astronomy

Resistance Temperature Detectors In A Cryostat Refrigeration System, Kirsten Marie Manahan, Alice Callen Jan 2018

Resistance Temperature Detectors In A Cryostat Refrigeration System, Kirsten Marie Manahan, Alice Callen

STAR Program Research Presentations

The Large Synoptic Survey Telescope (LSST) is a ground-based telescope that will survey the Southern sky every few nights. Located in the telescope will be a 3.2 gigapixel digital camera. To ensure proper instrumentation of the camera, there must be a monitored stable temperature. As part of my research, I assembled resistance temperature detectors and tested them to verify their reliability in measuring temperature in the camera’s cryostat refrigeration cooling system. Resistance temperature detectors function by the principle of thermal resistivity, in which their electrical resistances vary as temperature varies. Through testing, I was able to determine whether these particular …


Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney Oct 2016

Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) conducts research on a modified Boeing 747sp aircraft. By using a variety of infrared science instruments mounted on a 2.7 meter telescope, researchers can make discoveries about the galactic center, star formation, and various topics associated with a deeper understanding of our universe. To efficiently collect data through the SOFIA instruments, the instruments must be tested and prepared prior to being placed on the aircraft. Therefore, with the use of the Telescope Assembly Alignment Simulator (TAAS), researchers can design and construct improvements needed for these instruments to efficiently perform while in flight. The …


Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka Oct 2016

Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka

STAR Program Research Presentations

Dark matter is an unknown type of matter that composes roughly 27% of the observable universe and, as cosmological structure models suggest, the earth should be passing through a “dark halo” of this unknown matter present in the Milky Way galaxy. As we pass through this halo, the Super Cryogenic Dark Matter Search (SuperCDMS) experiment aims to directly detect dark -matter particles. Though many dark matter particle candidates exist, SuperCDMS focuses on the detection of particles called WIMPS (weakly interacting massive particles) as predicted by super-symmetric theories beyond the standard model. Due to the high-sensitivity of the germanium detectors employed, …


Design And Fabrication Of Liquid Scintillator Counter, Andrea Calderon Saucedo, John L. Orrell Aug 2015

Design And Fabrication Of Liquid Scintillator Counter, Andrea Calderon Saucedo, John L. Orrell

STAR Program Research Presentations

Pacific Northwest National Laboratory (PNNL) is currently developing an ultra-low background liquid scintillator counter (ULB LSC) in the shallow underground laboratory. At a depth of 35-meters water-equivalent, the underground laboratory has a multi-layered shielding to keep out cosmic-ray induced background. The ULB LSC, which is located in a clean room facility, is a multi-layered design made up of various materials, including plastic scintillator veto panels, borated polyethylene, lead and copper. These layers help lower the contributions of the terrestrial background and intrinsic background, resulting from the impurities present in the materials, to the overall background count rate observed by the …


Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine Aug 2014

Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine

STAR Program Research Presentations

This research focuses on laser ranging developments for LISA (Laser Interferometer Space Antenna), a planned NASA-ESA gravitational wave detector in space. LISA will utilize precision laser interferometry to track the changes in separation between three satellites orbiting 5 million kilometers apart. Specifically, our goal is to investigate options for laser frequency stabilization. Previous research has shown that an optical cavity system can meet LISA's stability requirements, but these units are large and heavy, adding cost to the implementation. A heterodyne Mach-Zehnder interferometer could be integrated onto LISA’s existing optical bench, greatly reducing the weight, provided the interferometer meets the stability …


Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter Aug 2014

Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter

STAR Program Research Presentations

NASA’s Cold Atom Lab (CAL) is a multi-user facility designed to study ultra-cold quantum gases in the microgravity environment of the International Space Station (ISS). One of the main goals of CAL is to explore the unknown territory of extremely low temperatures—possibly as low as the picokelvin range!—where new and fascinating quantum phenomena can be observed. At such temperatures matter stops behaving as particles and instead becomes macroscopic matter waves. CAL will be remotely controlled to perform a multitude of experiments and is scheduled to launch in 2016. In order to anticipate problems that might occur during and post-launch, including …


Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer Aug 2014

Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer

STAR Program Research Presentations

Photometry is the measure of the brightness of an object. When making such measurements on stars, it is done is units of magnitude, which is on a logarithmic scale with a base of ~2.512. Variable star photometry using a commercially available digital camera is not going to be as accurate and precise as equipment used by astronomers, and because of the logarithmic scale of magnitude used, determining how much of an effect different error reduction strategies have is not straightforward, and is best done experimentally.

My research is conducting photometry on variable stars (changing brightness) with a digital camera, and …


Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson Aug 2013

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …


Flitecam Data Process Validation, Jesse K. Tsai, Sachindev S. Shenoy, Brent Cedric Nicklas, Zaheer Ali, William T. Reach Aug 2013

Flitecam Data Process Validation, Jesse K. Tsai, Sachindev S. Shenoy, Brent Cedric Nicklas, Zaheer Ali, William T. Reach

STAR Program Research Presentations

FLITECAM Data Processing Validation

Many of the challenges that come from working with astronomical imaging arise from the reduction of raw data into scientifically meaningful data. First Light Infrared Test CAMera (FLITECAM) is an infrared camera operating in the 1.0–5.5 μm waveband on board SOFIA (Stratospheric Observatory For Infrared Astronomy). Due to the significant noise from the atmosphere and the camera itself, astronomers have developed many methods to reduce the effects of atmospheric and instrumental emission. The FLITECAM Data Reduction Program (FDRP) is a program, developed at SOFIA Science Center, subtracts darks, removes flats, and dithers images.

This project contains …


Designing A Cold Source To Be Integrated With The Existing Telescope Assembly Alignment Simulator, Rebecca L. Salvemini, Carey Baxter, Zaheer Ali, Greg Perryman, Robert Thompson, Daniel Nolan Aug 2013

Designing A Cold Source To Be Integrated With The Existing Telescope Assembly Alignment Simulator, Rebecca L. Salvemini, Carey Baxter, Zaheer Ali, Greg Perryman, Robert Thompson, Daniel Nolan

STAR Program Research Presentations

The stratospheric observatory for infrared astronomy (SOFIA), is a modified Boeing 747-SP with a 2.5m telescope mounted inside. SOFIA flies at an altitude of 45,000 feet, above 99% of the water vapor in the atmosphere, allowing transmission of most infrared radiation. SOFIA has seven different science instruments (SI) that can be used to collect astronomical data, enabling scientists to look at many different wavelengths of infrared and visible radiation.


Telescope Assembly Alignment Simulator Performance Optimization, Joshua G. Thompson, Brian Eney, Zaheer Ali, Bob Thompson Aug 2012

Telescope Assembly Alignment Simulator Performance Optimization, Joshua G. Thompson, Brian Eney, Zaheer Ali, Bob Thompson

STAR Program Research Presentations

The Telescope Assembly Alignment Simulator (TAAS) calibrates scientific instruments (SI’s) that are installed on the Stratospheric Observatory For Infrared Astronomy (SOFIA). An SI’s accuracy is directly dependent on the consistent performance of the TAAS, which has never been fully characterized. After designing various thermal and optical experiments to identify the current unknowns of TAAS, we now have a far better grasp on how the equipment behaves.


Leds And Astronomy, Britny N. Delp, Stephen M. Pompea Aug 2012

Leds And Astronomy, Britny N. Delp, Stephen M. Pompea

STAR Program Research Presentations

Using a Czerny-Turner spectrometer, 45 different types of outdoor lights were categorized. These spectra were used to determine how useful the light is to human eyes and how dark skies friendly these lights are. Dark skies friendly lighting means that little to no light shines above a right angle to the light, and should emit as little as possible below 500nm (green) wavelengths. The short wavelengths present a problem to astronomers in the form of Rayleigh scattering. The following criterion were used in selecting the best source for urban and rural lighting: color rendition measured by color rendering index (CRI), …


The Role Of Llnl's Fast Calibration Facility In Diagnosing Nif Fusion Plasmas, Joshua G. Thompson, Carey Scott, Greg V. Brown Aug 2011

The Role Of Llnl's Fast Calibration Facility In Diagnosing Nif Fusion Plasmas, Joshua G. Thompson, Carey Scott, Greg V. Brown

STAR Program Research Presentations

The Fusion and Astrophysics (FAST) Calibration and Diagnostic Facility uses the original Electron Beam Ion Trap (EBIT-I) to profile x-ray filters that are used in the Dante Soft X-Ray Diagnostic at the National Ignition Facility (NIF). FAST has an advantage over any other facility not only for its high accuracy, but also for its proximity to NIF in the Lawrence Livermore National Laboratory (LLNL). This makes for highly accurate and near-instantaneous filter calibration turnover.

EBIT-I was first constructed to create, trap, and observe static highly charged ions (HCIs) and conduct experimental astrophysics (creating an x-ray spectroscopy catalogue of ions). To …


Laboratory Astrophysics: Using Ebit Measurements To Interpret High Resolution Spectra From Celestial Sources, Carey Scott, Joshua Thompson, N. Hell, Greg V. Brown Aug 2011

Laboratory Astrophysics: Using Ebit Measurements To Interpret High Resolution Spectra From Celestial Sources, Carey Scott, Joshua Thompson, N. Hell, Greg V. Brown

STAR Program Research Presentations

Astrophysicists use radiation to investigate the physics controlling a variety of celestial sources, including stellar atmospheres, black holes, and binary systems. By measuring the spectrum of the emitted radiation, astrophysicists can determine a source’s temperature and composition. Accurate atomic data are needed for reliably interpreting these spectra. Here we present an overview of how LLNL’s EBIT facility is used to put the atomic data on sound footing for use by the high energy astrophysics community.