Ultrafast X-ray provides new look at plasma discharge breakdown in water
A better understanding of the phenomena could lead to advances in green
energy production

Date:
July 30, 2021
Source:
Texas A&M University
Summary:
Occurring faster than the speed of sound, the mystery behind the
breakdown of plasma discharges in water is one step closer to being
understood as researchers pursue applying new diagnostic processes
using state-of-the-art X-ray imaging to the challenging subject.



FULL STORY ========================================================================== Occurring faster than the speed of sound, the mystery behind the
breakdown of plasma discharges in water is one step closer to being
understood as researchers pursue applying new diagnostic processes using state-of-the-art X- ray imaging to the challenging subject.


========================================================================== These diagnostic processes open the door to a better understanding of
plasma physics, which could lead to advances in green energy production
through methods including fusion, hydrocarbon reforming and hydrogen generation.

Dr. David Staack and Christopher Campbell in the J. Mike Walker '66
Department of Mechanical Engineering at Texas A&M University are part of
the team pioneering this approach to assessing plasma processes. Partners
on the project include diagnostics experts from Los Alamos National Laboratories and using the facilities at the Argonne National Laboratory Advanced Photon Source (APS).

The team is working with LTEOIL on patented research into the use of
multiphase plasma in carbon-free fuel reforming. The research is supported
by the dynamic materials properties campaign (C2) and the advanced
diagnostics campaign (C3) at Los Alamos National Laboratories through
the Thermonuclear Plasma Physics group (P4) principal investigator,
Zhehui (Jeph) Wang.

The research, which was recently published in Physical Review Research,
is producing the first-known ultrafast X-ray images of pulsed plasma
initiation processes in water. Staack, associate professor and Sallie
and Don Davis '61 Career Development Professor, said these new images
provide valuable insight into how plasma behaves in liquid.

"Our lab is working with industry sponsors on patented research into the
use of multiphase plasma in carbon-free fuel reforming," Staack said. "By understanding this plasma physics, we are able to efficiently convert tar
and recycled plastics into hydrogen and fuels for automobiles without
any greenhouse gas emissions. In the future, these investigations may
lead to improvements in inertial confinement fusion energy sources."
Inertial confinement fusion -- in which high temperature, high energy
density plasmas are generated -- is a specific focus of the project. To
better understand the plasma physics involved in this type of fusion,
Staack said the team is developing short timescale, high-speed imaging
and diagnostic techniques utilizing a simple, low-cost plasma discharge
system.



========================================================================== Additionally, they are seeking to better understand the phenomena that
occur when plasma is discharged in liquid, causing a rapid release of
energy resulting in low-density microfractures in the water that move
at over 20 times the speed of sound.

Campbell, a graduate research assistant and Ph.D. candidate, said the
team hopes their discoveries can prove to be a valuable contribution to
the collective knowledge of their field as researchers seek to develop
robust predictive models for how plasma will react in liquid.

"Our goal is to experimentally probe the regions and timescales of
interest surrounding this plasma using ultrafast X-ray and visible imaging techniques, thereby contributing new data to the ongoing literature
discussion in this area," said Campbell. "With a complete conceptual
model, we could more efficiently learn how to apply these plasmas in
new ways and also improve existing applications." Although they have
made progress, Campbell said current methods are not yet sophisticated
enough to collect multiple images of a single plasma event in such a
short amount of time -- less than 100 nanoseconds.

"Even with the state-of-the-art techniques and fast framerates available
at the Advanced Photon Source, we have only been able to image a single
frame during the entire event of interest -- by the next video frame, most
of the fastest plasma processes have concluded," Campbell said. "This work highlights several resourceful techniques we have developed to make the
most of what few images we are able to take of these fastest processes."
The team is currently working to measure the pressures induced by the
rapid phenomena and preparing for a second round of measurements at APS
to investigate interacting discharges, discharges in different fluids and processes that may limit confinement of higher energy discharges. They
look forward to the opportunity of using even higher-framerate X-ray
imaging methods ranging up to 6.7 million frames per second, compared
to 271 thousand frames per second in this study.

========================================================================== Story Source: Materials provided by Texas_A&M_University. Original
written by Steve Kuhlmann.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Christopher Campbell, Xin Tang, Yancey Sechrest, Kamel Fezzaa,
Zhehui
Wang, David Staack. Ultrafast x-ray imaging of pulsed plasmas
in water.

Physical Review Research, 2021; 3 (2) DOI: 10.1103/
PhysRevResearch.3.L022021 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/07/210730142052.htm

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