Researching Experimental Plasma Physics at Concordia College

Amy Ott (’21) and Noel Geiger (’22) worked with Dr. Matthew ArchMiller in developing computational tools to support experimental plasma physics. While developing these tools, the students became proficient in Python programming with emphasis placed on specific techniques that are useful for physical modeling. Amy wrote a spectral analysis program that allows the user to interactively fit spectral data containing any number of spectral lines. The code includes various models for line shape and does an uncertainty analysis of fitted parameters. Noel wrote a program that simulates a Langmuir probe’s diagnostic response to a plasma, which is useful for understanding experimental results. His program goes beyond the basic probe theory, where electrons are assumed to have a single Maxwellian distribution function. Noel’s program can integrate any prescribed distribution function, with perhaps multiple electron populations, and calculates the current collected by the probe as the probe voltage is varied. The plasma potential and various probe geometries may also be set. This program, for example, allows one to model a beam of electrons moving through a thermal plasma and its effect on the probe’s characteristic curve. Along the way, both Amy and Noel learned best practices for coding in general – commenting and documentation, debugging and error handling, verification and validation – while receiving support from the Minnesota Space Grant Consortium.