Magnetized Electron-Ion Collision and Rydberg Atom Formation Rates in Ultracold Plasmas
Abstract
Plasmas are a state of matter in which atoms are ionized, leading to a collection of electrically interacting ions and electrons. Plasmas are common throughout space, the atmosphere, and in laboratory environments. While usually plasmas are hot, it is possible to create plasmas that are cold – including socalled ultracold plasmas with temperatures just degrees above absolute zero. These plasmas lend themselves to precise control and measurement. Studies of ultracold plasmas can improve the understanding of plasma properties that are also present in more complicated and difficult to produce plasmas such as those in certain astrophysical settings, in certain types of fusion experiments, and created by intense laser pulses.In the proposed work, two aspects of the interaction between the electrons and ions in ultracold plasmas are to be measured. First, the rate at which electrons and ions collide to recombine to form atoms will be measured via electric field ionization. This recombination has important impacts on plasma density and temperature. There is a predicted rate for such atom formation, but for too cold or too dense plasmas this prediction produces absurdities and must break down. In the proposed work, the breakdown of this predicted rate for cold plasmas will be studied. In the second aspect, the collision rate between electrons and ions when the electrons are strongly magnetized will be measured through inducing electron oscillations in the ultracold plasmas and then measuring their decay. Magnetic fields in plasmas are common, and electron-ion collisions are important for how the plasmas behave but are often difficult to measure, making measuring these collisions in ultracold plasmas useful. Understanding these experiments engages start-of-the-art theoretical techniques, pushing and validating those techniques and then allowing translation of these results to other plasmas to better describe and model their behavior for scientific and technical uses.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2017
- Source ID
- FA95501710148
Entities
People
- Jacob L. Roberts
Organizations
- Air Force Office of Scientific Research
- Colorado State University
- United States Air Force