Ross Fontenot

Unusual fluorescence emission characteristics from europium-doped lead phosphate glass caused by 3 MeV proton irradiation

In 1951, Birks and Black showed experimentally that the fluorescence efficiency of anthracene bombarded by alphas varies with total fluence (N) as (I/I0) = 1/(1 + AN), where I is the fluorescence yield, I0 is the initial light yield, and A is a constant. Schulman observed a similar effect to the Birks and Black equation when organic anthracene was exposed to gamma irradiation. Black later observed no efficiency degradation when the phosphor was exposed to 40 keV electrons, since they only cause ionization damage with no atomic displacements. Broser and Kallmann developed a similar relationship to the Birks and Black equation for inorganic phosphors irradiated using alpha particles. These results indicate that radiation produced quenching centers compete with emission centers for absorbed energy. From 1990 to 2005, the Birks and Black relation described the reduction in emission yield for all fluorescent materials tested by the authors. In 2006, new data indicated the emission yield increased or remained constant when europium-doped lead phosphate glass samples were irradiated with 3 MeV protons. The purpose of this paper is to present the new 3 MeV irradiation results for the europium-doped lead phosphate glass samples.

Results from Two Low Mass Cosmic Ray Experiments Flown on the HASP Platform

The High Altitude Student Payload (HASP) program is designed to carry twelve student experiments to an altitude of about 123,000 feet (∼37u2009km). In 2006, students participated in the first HASP launch to measure cosmic ray intensities using traditional film and absorbers. This 10 kg payload flew from Fort Sumner, New Mexico in early September 2006 and was a great success. In 2007, students participated in the second HASP flight to measure the cosmic ray intensity and flux using a traditional film and absorber stack with five layers of optically stimulated luminescent (OSL) dosimeters. Results from both payloads showed that the cosmic ray flux decreases as a function of payload depth. As the cosmic rays go through the stack, they deposit their energy in the payload material. Determining cosmic ray flux is a tedious task. It involves digitizing the film and determining the real cosmic ray density. For the first HASP payload, students used a program known as GlobalLab to count particles. For the second payloa...

Results from the low mass cosmic ray experiment on the HASP balloon

The Louisiana High Altitude Student Payload (HASP) program is designed to carry twelve student payloads to an altitude of about 36 km with flight durations of more than sixteen hours. Payloads are designed and built by college and university students and are used to test compact satellites and to fly other related space science experiments. The major goals of HASP are to foster student excitement in an aerospace career path and to help address workforce development issues in Louisiana. HASP plans to provide a space test platform to encourage student research and stimulate the development of student satellite payloads and other space-engineering products. In 2006, physics students from the University of Louisiana at Lafayette built a low mass cosmic ray detector using aluminum absorbers and standard x-ray film (with image intensifiers). This 10 kg payload flew from the Columbia Scientific Balloon Facility in Fort Sumner, New Mexico in early September 2006 and was a great success. The students are currently analyzing data from a second 10 kg nuclear stack detector that was flown in September 2007. The purpose of this paper is to present results from the 2006 and 2007 flights of our low mass cosmic ray detector. Emphasis will be placed on the hands-on and step-by-step approach used to provide students with practical space-related skills developed as part of the HASP program.

Training Physics Students for Space Careers: Introduction to the LaACES CajunSat Program

In January 2004, the President set goals for our space program for the 21st century. This renewed sense of direction means that a whole new generation of scientists and engineers will be needed to support space-based science and technology. Declining enrollments in science, mathematics, and space related engineering programs are well documented in the United States. These enrollment reductions are also observed at Louisiana colleges and universities. During the 2002-2003 academic year, Louisiana State University (LSU) was able to involve approximately fifteen undergraduate students in the design, development, fabrication and operation of their own balloon experiment under the Louisiana Aerospace Catalyst Experiences for Students (LaACES) program. In 2004-2005, the University of Louisiana at Lafayette extended the highly successful LaACES project for several of its physics undergraduates. Using the LSU model, UL Lafayette developed an informal ballooning course to design and build a student-directed payload (CajunSat) for launch at the NASA National Scientific Ballooning Facility in Palestine, Texas. This presentation provides details of the LaACES CajunSat balloon project. Emphasis will be placed on highlighting the hands-on and step-by-step approach used to provide students with practical space related skills.