The Beam Plasma Interactions Experiment (Beam PIE): Wave Generation and Particle Interaction Using a Compact Linear Electron Accelerator

Geoff Reeves and Rebecca Holmes

Los Alamos National Laboratory

Active experiments in space provide the opportunity to perturb the natural environment with known and controllable conditions. Active experiments using electron beams are particularly well-suited to studying wave-particle and wave-wave interactions. Results from rockets, the Space Shuttle, and satellites provided important contributions to our understanding of both linear and non-linear plasma physics. Since the heyday of active experiments in the 1970s and 1980s the technologies for conducting electron beam experiments and for collecting high-resolution measurements have advanced considerably. These new technologies provide opportunities for a new generation of electron beam experiments. Here we discuss an active Beam-Plasma Interactions Experiment (Beam PIE) on a sounding rocket scheduled for launch from Poker Flat Research Range in 2021. Beam PIE uses an RF linear accelerator to produce an electron beam with a highly configurable range of energies, frequencies, and duty cycles. The Whistler and R-X-mode waves that a pulsed electron beam produces are sensitive to all three parameters and to the background plasma conditions. Beam PIE will measure these conditions and the detailed characteristics of the waves (including full 3D waveform capture) to investigate both linear and non-linear beam-plasma-wave interactions. The mission design, science objectives, and expected results will be discussed. We will also discuss a unique single-photon camera that will be used for ground-based measurements during the rocket flight. Beam PIE’s pulsed electron beam will create an artificial aurora when it interacts with the upper atmosphere. This light emission can be measured from the ground to provide additional information about accelerator performance. We will use NCam (Nocturnal Camera), a sensor developed at Los Alamos National Laboratory, to measure the artificial aurora from Beam PIE. NCam creates an image one photon at a time, with extremely high time resolution, enabling many unique applications.