Physics of Solar Flares and Development of Statistical and Data Driven Models. ADA591356

Solar flares impact DoD and civilian space- and ground-based assets. The current state of predictability of solar flares, such as the probability of a solar flare occurring (NOAA Space Weather Prediction Center, and USAF/AFWA) are evaluated based on once-a-day measurement and resultant change of solar activity parameters, such as sunspot magnetic classification. With the advent of the USAF s prototype Improved Solar Observing Optical Network telescope, we have the capability to monitor rapid changes in characteristics of the solar chromosphere (1-minute cadence), photosphere (5-minute cadence) and corona (10- minute cadence). We will also use the GOES x-ray data (1-minute cadence) and other space data to complement these measurements. These data sources of past and current data will help us research, track and establish the relationship between the high-cadence variation of measured parameters at the various layers (sunspot umbral and penumbral areas, plage index, magnetic flux, sequential chromospheric brightenings, development of flare ribbons, etc.) and solar flares. We will research the seemingly heterogeneous and voluminous parameterized observational data to understand the measures needed for flare forecasts, incorporating such techniques as principal component analysis, discriminant analysis, genetic algorithms and neural networks. The goal is to demonstrate parameters that could be used in real-time operations to predict the near-term probability of flare occurrence. This research will help gain insights into physical mechanisms of the flaring proF298cess. It will aid in the development of physics-based solar flare forecast models. This report provides the final summary of the work performed under this AFOSR task. Individual and interim technical work has been published in peer-reviewed journals and presented in professional society meetings as appropriate
Personal Author Balasubramaniam, K. S.; Norquist, D. C.; Henry, T.; Kirk, M.
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Eliminating Crystals in Non-Oxide Optical Fiber Preforms and Optical Fibers

images[7]Non-oxide fiber optics such as heavy metal fluoride and chalcogenide glasses are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. The addition of rare earths such as erbium, enable these materials to be used as fiber laser and amplifiers. Some of these glasses however are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. Previously two research teams found that microgravity suppressed crystallization in heavy metal fluoride glasses. Looking for a less expensive method to suppress crystallization, ground based research was performed utilizing an axial magnetic field. The experiments revealed identical results to those obtained via microgravity processing. This research then led to a patented process for eliminating crystals in optical fiber preforms and the resulting optical fibers. In this paper, the microgravity results will be reviewed as well as patents and papers relating to the use of magnetic fields in various material and glass processing applications. Finally our patent to eliminate crystals in non-oxide glasses utilizing a magnetic field will be detailed.
Personal Author D. S. Tucker M. R. LaPointe or call NTIS 800-553-6847 M – F 8am – 5pm est
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