Universality in the Equilibration of Quenched Yukawa One Component Plasmas

A Yukawa one-component plasma (OCP) is an idealized model in which particles interact through a 1/r potential with an additional exponential falloff with length scale 1/κ expressed in units of the average interparticle spacing. This model is used to approximately describe a wide range of physical systems, especially strongly coupled plasmas; i.e., those which have Γ≥1, where Γ is the ratio of the Coulomb interaction energy between neighboring particles to the kinetic energy per particle. All dynamics and physical properties in Yukawa OCPs are expected to be universal in κ when expressed in appropriate scaled units. We study a particularly clean realization of the Yukawa OCP, an ultracold neutral plasma (UNP) created by photoionization of an ultracold atomic gas. The rapid quench to a UNP results in an equilibration process known as Disorder Induced Heating (DIH). Even after DIH the plasma is strongly coupled, with Γ~3. During DIH, oscillations in 1/Γ (i.e. scaled Kinetic Energy) occurring at twice the plasma frequency, ω_{pi}, are observed, possibly indicating coupling to collective modes. Universality is demonstrated by showing that 1/Γ(t) curves taken at similar κ collapse onto the same curve when plotted vs. ω_{pi}t. We also compare our results to molecular dynamics (MD) simulations. The utility of the universality is shown by using the MD simulations to determine the density from experimental DIH measurements.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Natural Sciences

Grantor

Rice University

Year dc:date.issued

2016

Author dc:creator

• Langin, Thomas Karl

Advisor dc:contributor.advisor

• Killian, Thomas C

• Plasma Physics
• Atomic Physics
• Strontium

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/107997

OAI identifier oai:identifier

oai:repository.rice.edu:1911/107997