Fast Calculation of the Radiative Opacity of Plasma

Plasma opacity calculations play an important role in solar modelling and many plasma physics and inertial confinement fusion experiments. This thesis is focussed on the fast calculation of opacity from first principles. The existing average atom (AA) opacity code IMP [1] is used alongside experimental data and detailed atomic physics to develop new models; the results show that simple models can give an excellent description of plasma spectra for a large range of conditions. The results are significant for the development of fast opacity codes which necessarily use the AA approach. The application of fast models to very large scale calculations is considered and an efficient approach to these developed; this allows the fast description of experimental data that would not have otherwise been possible [2]. Analysis of this data then allows the accuracy of the IMP model to be further discussed. The atomic model is also considered, and an improved approach implemented. These improvements makes little difference to the description of experiment provided electron exchange is included. The range of applicability of the IMP model is then extended to higher density by adding a fast description of line broadening by electrons. This gives an excellent agreement with both experiment and more advanced opacity codes. The treatment of atomic term structure can represent a significant portion of code runtime. A good compromise between detail and efficiency is the unresolved transition array (UTA) formulation; a consistent theory of UTAs is developed, and various models introduced. The accuracy of these is systematically tested. It is found that within the validity range of the UTA approach, a good description of the opacity can be gained using a simple model provided that the linewidth is correct. Various simplified calculations of this width are tested, and found to be inaccurate [3]

Afghan Narcotrafficking Post-2014 Scenarios

As Afghanistan now faces an uncertain political and security environment following the drawdown of ISAF troops at the end of 2014, the potential for a worsening narcotrafficking threat is great. The report states that the potential for deterioration "underscores the imperative need for Russian and U.S. policymakers to find the political will to resume and perhaps even increase cooperation despite ongoing differences on other issues. Together with regional partners and international organizations, renewed Russian-U.S. cooperation presents the best hope for a brighter future.

A Study of Two Newly-Discovered Eclipsing Binary Systems

I have observed three newly-discovered variable stars using the 16-inch telescope and CCD at the Valparaiso University Observatory. Of these three variables, two have been verified as binary star systems, where one of the stars passes in front of the other. The third is found to be a pulsating variable, which varies due to a change in its size and temperature. One of the goals of this project has been to further refine the periods of these three variables. From my new data and some previous observations at the Valparaiso University Observatory, I have been able to determine that the brightness of the three systems has varied from 13-55 percent. I have improved upon the determination of the periods of these variables. For the two binary systems, the periods are 0.52 and 1.21 days. For the pulsating variable, the period is 0.32 days. I have formed light curves for each star showing the change of brightness over one cycle. For the two binaries, the light curves are being analyzed to determine the relative sizes and differences in temperature of the two stars in each system. All of this is a part of my senior research project in physics and astronomy