SOURCE 2019

​Watch the session live or the recording after.​​​

Jeffrey Jensen - Acquiring First-Order Coherence Measurements for a HeNe Gas Laser Using a Michelson Interferometer
A HeNe laser was used as a source in a Michelson interferometer apparatus to develop a process for making quantitative coherence measurements of the laser light. While investigating these measurements, interesting phenomena were observed that appeared to be associated with multiple wavelengths of light. When scanning the length of the interferometer arm, an interference pattern that correlated with the 14 cm length of the laser cavity was found. A periodic shift between almost complete constructive and destructive interference occurred every 14 cm down the arm, but was absent in between. We attempted detection of a beat frequency from the laser which yielded no results until a polarizer was placed in front of the laser, and at two angles perpendicular to each other the polarizer almost completely extinguished the laser light. To see the beat frequency required the polarizer to be 45 degrees relative to these polarization angles of the light. The beat frequency and polarizer adjustments therefore showed two different wavelengths and polarizations of light coming from the laser which alternate periodically, suggesting that the laser was scanning between two orthogonally polarized wavelengths as it operated. The rate at which the laser flipped between wavelengths was strongly correlated with the rate of shift in the interference pattern, providing strong evidence for their relationship with the coherence measurements.

Trent English - Portable Muon Detector
This presentation will describe the construction of a portable muon detector for education and research purposes. When cosmic rays hit the Earth’s atmosphere they produce a cascade of high energetic particles comprised of pions and neutrons, these energetic particles are unstable in nature and will eventually decay. The byproducts of the decaying charged pions are known as muons, a muon is a subatomic particle that is similar to an electron but is larger in mass. Most of the energetic particles that reach the surface of the Earth are muons. The detector will measure muon flux as a function of altitude on board a high-altitude balloon (HAB) using a scintillator that emits light when a charged particle passes through it. A silicon photomultiplier will detect the light pulses and send a voltage spike which will be counted and recorded by an Arduino Nano. As the detector increases in elevation we expect the rate of muon detections will increase until the balloon reaches 15 km above sea-level. The peak muon production occurs at 15 km due to both the relatively high density of air molecules and the high flux of cosmic rays, which is attenuated at lower altitudes. In addition to detecting muons on a HAB, the portable battery-powered detector will be used for particle physics demonstrations and other research projects.

Jeffrey Sargent and Brad Hardt - Using High Altitude Balloons to Study the Effects of Ultraviolet Radiation on Bacteria
UV light has a mutagenic effect on bacteria and can even kill bacteria. The ozone layer blocks out all but 1-3% of the UV light in the upper atmosphere. This project is testing the effects of UV light in the upper atmosphere on a strain of E. coli bacteria altered with the pGLO plasmid, causing the bacteria to glow green under a UV light. The E. coli bacteria being used are more resilient to UV light and the colder temperatures experienced at altitude. Samples will have various levels of UV filtering to determine the limit of survivability among colonies. In an earlier experiment, samples of E. coli were sent up into the atmosphere to see what effect the UV light had on the samples. The first samples came back without any growth due to an issue with the preparation of the samples. Weather was another obstacle that cut the flight short, causing the balloon to not reach the upper portions of the ozone layer. In preparation for a future flight the bacteria has been tested for viability and preparation methods have been modified, improvements to the instrumentation package have also been made. After the bacteria from the second flight is incubated, there should be colonies of bacteria that been killed off, but other colonies should have mutated. However, if there is no effect on the bacteria, there will be no bacteria showing mutations.

Joshua MacLurg - Thrust Table for Measuring High-Power Model Rocket Engines
As the field of astronautical engineering continues to grow, the demand for workers having experience with thrust analysis and rocketry grows as well. The goal of this project is to design and manufacture a thrust table to be used in future projects involving high-power model rockets. The thrust table is designed using a rail system with extruded aluminum and aluminum base plate, and electronics based on Arduino to measure thrust and chamber pressure in the rocket engine. The data collected is then used in a Matlab model to predict the flight of the rocket. Initial testing shows the table returns reliable thrust measurement, but further testing is needed to improve measurements of chamber pressure. The next step in this project is to use the table to test nozzle properties’ effects in the thrust of the motors, and to optimize those properties for maximum thrust and efficiency.