The Design of a Rocket-Based RF Electron Accelerator for Space Applications
Christopher Roper, Georgia Institute of Technology
Beam Plasma Interactions Experiment (Beam-PIE) is a NASA sounding-rocket experiment that successfully ran in November 2023. Beam-PIE used space as a laboratory to explore wave generation from a modulated electron beam in the ionosphere. The Beam-PIE electron accelerator used a 10keV electron gun and a 5-GHz RF cavity, enabling the acceleration of the electron beam to a total energy of ~25–60 keV. The experiment was pulsed at VLF frequencies ranging from 5 to 500 kHz. The third free parameter was duty cycle which ranged from 2.5% to 10%. In total 32 different combinations of beam parameters were used and repeated every 32 seconds through the flight at various altitudes and background plasma conditions. Each of these different beam parameters ran for a ½-second beam pulse, separated by ½-second intervals when the beam was off. Further, the accelerator and wave detector payloads separate over the course of the flight to test different propagation distances parallel to the magnetic field. Beam-PIE was successful at generating plasma waves. We present an outline of the accelerator design, preliminary theoretical predictions, and experimental results of generated plasma waves. Results will be used to quantitatively test our understanding of beam-plasma-wave interactions in the space environment. This study contributes valuable insights into controlled beam-plasma interactions in space, with potential applications in space-based communication and radiation belt remediation systems.