Physics Commons^™

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 …

A Prototype Microwave Cavity Control Circuit For Use In Next Generation Free Electron Laser, Josh Thompson, Peter Neal Barrina, Jiayi Jiang, Joe Frisch, Steve Smith, Daniel Van Winkle

STAR Program Research Presentations

One of the current programs at SLAC National Accelerator Laboratory is the Linac Coherent Light Source, or LCLS. Using the existing hardware of the last third of their linear accelerator (or “linac”), SLAC has created one of the most energetic X-ray free electron lasers (or “FEL”). Since 2009, LCLS has used this FEL to perform a wide range of experiments across all sciences, most notably ultrafast filming at the molecular scale. As requests for beam-time with this laser increases, SLAC is purposing a linac upgrade to better match this demand. This upgrade, named LCLS-II, will replace existing copper radio frequency …

Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Superamphiphobic surfaces strongly repel both water and oils. In this work, aluminum coupons are processed by sanding with various grit of sand paper to impart microscale roughness. Subsequent submersion of the aluminum substrate in boiling water grows nanoscale grass-like structures. The oxide layer of Al is slightly soluble in water. During a fast diffusion/equilibrium, Al₂O₃ nanograss grows on the surface. A low energy coating is then deposited on the surface. The micro and nanoscale features create re-entrant structures that trap air enabling contact liquid to be in a Cassie-Baxter state. Superamphiphobicity of the samples were confirmed by …

Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde

STAR Program Research Presentations

This project explores the stability analysis of a given flow field. Specifically, where the peak disturbance occurs in a flow as this is the disturbance that is most likely to occur. In rocket combustion, it is important to understand where the maximum disturbance occurs so that the mixing of fuel can be stabilized. The instabilities are the results of frequencies in the area surrounding the flow field. The linear stability governing equations are employed to better understand the disturbance. The governing equations for continuity and momentum in the x and y directions are used to form an equation for the …

Feedback Stabilization At Spear3, Daniel Kelley, Jeff Corbett

STAR Program Research Presentations

The SPEAR3 synchrotron lightsource at SLAC relies on a sophisticated radio frequency (RF) timing system to maintain current – electrons – in the storage ring. One problem SPEAR3 operators have dealt with is the thermal expansion of one of the cables supporting this RF timing system. As the cable expands and contracts with the diurnal rise and fall of the sun, the phase of the RF in the cable shifts. This shifting phase affects the timing accuracy of electron injections into the storage ring.

A common feedback control algorithm PID (Proportional Integral Derivative) has countless applications in engineering. PID feedback …

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.

Electronics Development For The Cherenkov Telescope Array, Margaret C. Murphy, Justin Vandenbrouke

STAR Program Research Presentations

Gamma-ray astronomy promises to elucidate the highest-energy particle accelerators in the Universe, and could play a key role in identifying the nature of dark matter. The Cherenkov Telescope Array (CTA), currently in the research and development stage, will study and capture gamma-rays with an order of magnitude grater sensitivity than the instruments already in place. Each telescope in the array will be equipped with dozens of camera modules each containing four TeV Array Readout with GSa/s sampling and Event Trigger (TARGET) chips. TARGET 4 has many internal settings, several of which were tested and analyzed to achieve an optimal operating …

Analyzing Wind Turbine Controller Effects On Structure Stress, Leo Groner, Susan Frost

STAR Program Research Presentations

Wind turbines generate electric power from clean renewable sources. They must be robust and reliable. Utility-scale turbines are designed to produce power within a set of wind speed parameters. When winds change, wind turbine blade pitch is used to protect the turbine from over speed damage.

Advanced control algorithms can increase power by extending the performance envelope or they can extend lifetime by reducing stress. A FAST simulation written in MATLAB / Simulink is used to simulate the dynamics of the integrated aerodynamic, mechanical and control subsystems of the turbine. Resonance modes may lead to large amplitude displacements and damage. …

Assessing Laser Lifetime Test Performance, Joe Weichman, Hamid Hemmati, Malcolm Wright

STAR Program Research Presentations

Assessing expected component lifetime is necessary in developing instruments for future space-flight projects to ensure long term operation in the challenging environment. Although semiconductor diode lasers have widespread use in terrestrial applications, their use in space is still an emerging technology that requires on-going testing to demonstrate their capability. The project called for re-establishing the test setup for assessing lifetime performance of 20 continuously running 200mW 830 nm diode lasers. These lasers underwent previous testing based on parameters for NuSTAR’s laser metrology system, and met the six month lifetime project requirements under nominal operating conditions. Laser testing is currently underway …