Department of Physics and Astronomy

Abstract: Each of the fundamental forces has constants associated with its strength.  One of the constants for the weak force is the p.meson-coupling coefficient.  There is a proposed experiment to measure this constant using deuterium capturing polarized neutrons to make tritium and polarized gamma rays.  The calculation of the p.meson-coupling coefficient requires that the neutrons be polarized when they are captured.  Unfortunately, the capture process is not very efficient so there is a possibility that before it is captured the neutron will lose its polarization.  The degree of neutron polarization can be measured by passing the polarized gamma rays through devices containing polarized electrons in the form of magnetized metal.  Two of these devices, called polarimeters (POL), have been built and initial tests have been performed.

Abstract: In order to determine the p. weak meson coupling constant, neutrons will need to maintain a significant amount of their polarization when captured by the deuterium.  Neutron capture in deuterium is not very efficient and the neutrons will bounce' around considerably before merging with a deuterium nucleus.  Each "bounce" provides a significant opportunity for neutron depolarization.  If too many neutrons are depolarized, the experiment won't be practical to perform.  In order to measure the polarization, we need to construct a device that enables us to determine the polarization of gammas, which in turn will lead us to determine the polarization of neutrons.  Part of the data acquisition system includes the ADC.

Abstract: In 1989 the European Space Agency launched the Hipparcos satellite, carrying Tycho, a photometric instrument, which collected data for over a million stars. Some of these stars were identified as possibly being variable stars. However, further research is needed to confirm the variability of these stars. The purpose of our research was to determine whether or not one of these suspected variable stars, HD 333933, is actually variable. Before collecting data on HD 333933, we collected data for a known variable star, DY Pegasi, to refine our methods.

Abstract: The detection of silicon monoxide (SiO) in the interstellar medium was first reported by Wilson et al. (1971) in its microwave emission.  Since then SiO has been detected in over 200 stellar sources and shown to be an ubiquitous inhabitant of the universe.   Understanding SiO is very important in fields such as astrophysics and atmospheric science.  Therefore, comprehending the fundamental properties of especially the most abundant isotope SiO is significant to better understanding of various astrophysical phenomena.  The focus of this work is to find the potential function of SiO, which would provide necessary foundation on evaluation its wave function and dipole moment function.

Poster

Abstract: The Department of Physics and Astronomy proposed the addition of a Solar Observatory on the roof of Julian that would provide a real time display of the Sun, both in white light and H-alpha filtered, in the atrium of the renovated Julian Science and Mathematics Center. The Solar Observatory would consist of two refracting telescopes, which operating in a siderostat configuration [where a single mirror is turned to follow the Sun while the telescope remains pointed toward the celestial pole (Figure 4)], enclosed in a housing structure form the Julian roof on top of the penthouse.  The telescopes could continuously observe the sun during the daylight hours in Greencastle, Indiana.
The telescopes would be controlled form a computer located in Room 402.  The computer would control the opening and closing of the housing over the siderostat mirrors and automatically adjust the tilt of the mirror to compensate for the changing declination of the sun.  The images would be transmitted via the Internet and displayed on flat screen computer monitors in display cases in the northwest corner of the first floor Julian atrium.

Abstract: The gas jet target in use at the Triangle Universities Nuclear Lab (TUNL) allows to be performed with fewer contaminants and more precision than other types of accelerator targets.  However, the high volume of gas flow requires a recirculation system in order to make experiments feasible.  The purpose of this project was to design and implement a control system for this recirculator.  For more details, refer to the accompanying Control System Operations Manual.