Here is the current schedule for the Spring 2026 semester

 

 

A COMPREHENSIVE LANGMUIR LAB STUDY ON THE 
MULTISCALE PROPERTIES OF STREAMERS 

Luis Contreras-Vidal

Streamers are the starting point of electrical discharges, initiating phenomena ranging from laboratory sparks to lightning and sprite discharges in the upper atmosphere. Although they occur on a wide range of pressure and length scales, streamers share common physical characteristics, including low conductivity and intense enhancement of the electric field at their tips. In these high-field regions, electrons can reach energies of approximately 100 eV or higher. This electric field enhancement plays a crucial role in runaway electron production, in which some electrons gain sufficient energy to trigger further ionization and emit X-rays.

This dissertation examines streamer-related processes across several orders of magnitude in physical scale. At kilometers scales, combined high-speed optical and radio-frequency measurements of sprite streamers collected during the summer of 2019 show that the increase in morphological complexity in sprite bodies is correlated with the increase in currents flowing through the discharge channels. At meter scales, analysis of lightning leader emissions shows that stepped leaders produce a harder photon energy spectrum than dart leaders, with a larger population of photons exceeding 1 MeV. At centimeter scales, laboratory experiments show that runaway electrons are produced very early during the discharge initiation phase, and no later than when the inception cloud breaks into streamers.

To support controlled laboratory investigations of these processes, this dissertation presents the development and implementation of instrumentation for the precise timing and controlled initiation of spark-gap triggered streamer discharges. The work focuses on a low-voltage trigger timing system capable of generating fast rise-time control signals that enable reliable nanosecond-scale control over discharge initiation. This timing capability provides a robust experimental foundation for detailed studies of streamer development and associated high-energy emissions in laboratory spark-gap discharges.

 

Zoom Link: https://nmtedu.zoom.us/j/97572348560pwd=OLHjHRLKVCeL1LnUsxGTFMLrDJagQv.1

Meeting Id: 975 7234 8560; Passcode: 677943