Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



RAY GUNS
Where does laser energy go after being fired into plasma?
by Staff Writers
Glasgow, Scotland (SPX) Mar 27, 2017


This is a simulation of slingshot electrons from a laser wakefield accelerator. Image courtesy Dr Enrico Brunetti, produced with software by OSIRIS.

An outstanding conundrum on what happens to the laser energy after beams are fired into plasma has been solved in newly-published research at the University of Strathclyde. The study discovered that the same forces that produce a bubble in plasma in the laser-plasma wakefield accelerator produce two additional low-energy but high-charge electron beams simultaneously with a low charge high energy beam. These high charge beams can have a thousand times more charge than the high energy beam.

Plasma, the state in which nearly all of the universe exists, can support electric fields that are 1,000 to 10,000 times higher than in conventional accelerators, simply by separating the positive and negative charged particles that makes up the plasma medium, which is quasi-neutral.

This can easily be achieved using an intense laser pulse, the light pressure of which pushes electrons out of its way, leaving behind the much heavier ions which remain in place and exert an attractive force on the displaced electrons. The displaced electrons then oscillate around the stationary ions resulting in a wake behind the laser pulse, in a similar manner to the wake behind a boat.

Because the laser pulse travels at a velocity close to that of light in vacuum, the wake can track and accelerate charged particles rapidly to very high energies, over extremely short lengths.

The research paper, entitled Three electron beams from a laser-plasma wake?eld accelerator and the energy apportioning question, has been published in Scientific Reports.

Professor Dino Jaroszynski, of Strathclyde's Department of Physics, led the study. He said: "The intense laser pulse we used, and the acceleration of the wake it creates, lead to a very compact laser wakefield accelerator, which is millimetres long, rather than tens of metres long, for an equivalent conventional accelerator. The plasma wake forms into something like a bubble-shaped, laser-powered miniature Van de Graaf accelerator, which travels at close to the speed of light.

"Some of the laser energy is converted to electrostatic energy of the plasma bubble, which has a diameter of several microns. Conventional accelerators store their microwave energy in copper or superconducting cavities, which have limited power-carrying capability.

"An interesting conundrum that has not been considered before is the question of where laser energy goes after being deposited in plasma. We know where some of this energy goes because of the presence of high-energy electrons emitted in a narrow, forward directed beam.

"One of these beams is emitted by a sling-shot action into a broad forward-directed cone, with several MeV (mega electron volt) energies and nanocoulomb-level charge. Paradoxically, another beam is emitted in the backward direction, which has similar charge but an energy of around 200 keV (kilo electron volt). These beams carry off a significant amount of energy from the plasma bubble.

"It is interesting to observe that answering a very basic question - where does the laser energy go? - yields surprising and paradoxical answers. Introducing a new technology, such as the laser-wakefield accelerator, can change the way we think about accelerators. The result is a very novel source of several charge particle beams emitted simultaneously.

"My research group has shown that the wakefield accelerator produces three beams, two of which are low energy and high charge, and the third, high energy and low charge."

Dr Enrico Brunetti, a Research Fellow in Strathclyde's Department of Physics and a member of the research group, said: "These beams can provide a useful high flux of electrons or bremsstrahlung photons over a large area, which can be used for imaging applications, or for investigating radiation damage in materials. If not properly dumped, they can, however, have undesirable side-effects, such as causing damage to equipment placed close to the accelerator.

"This is a particular concern for longer accelerators, which often use plasma wave guides based on capillaries to guide the laser beam over long distances. These low energy, high charge beams also carry a large amount of energy away from the plasma, setting a limit to the efficiency of laser-wakefield accelerators.

"This is an issue which needs to be taken into account in the future design and construction of laser-wakefield accelerators." An outstanding conundrum on what happens to the laser energy after beams are fired into plasma has been solved in newly-published research at the University of Strathclyde.

The study discovered that the same forces that produce a bubble in plasma in the laser-plasma wakefield accelerator produce two additional low-energy but high-charge electron beams simultaneously with a low charge high energy beam. These high charge beams can have a thousand times more charge than the high energy beam.

Plasma, the state in which nearly all of the universe exists, can support electric fields that are 1,000 to 10,000 times higher than in conventional accelerators, simply by separating the positive and negative charged particles that makes up the plasma medium, which is quasi-neutral.

This can easily be achieved using an intense laser pulse, the light pressure of which pushes electrons out of its way, leaving behind the much heavier ions which remain in place and exert an attractive force on the displaced electrons. The displaced electrons then oscillate around the stationary ions resulting in a wake behind the laser pulse, in a similar manner to the wake behind a boat.

Because the laser pulse travels at a velocity close to that of light in vacuum, the wake can track and accelerate charged particles rapidly to very high energies, over extremely short lengths.

The research paper, entitled Three electron beams from a laser-plasma wake?eld accelerator and the energy apportioning question, has been published in Scientific Reports.

Professor Dino Jaroszynski, of Strathclyde's Department of Physics, led the study. He said: "The intense laser pulse we used, and the acceleration of the wake it creates, lead to a very compact laser wakefield accelerator, which is millimetres long, rather than tens of metres long, for an equivalent conventional accelerator. The plasma wake forms into something like a bubble-shaped, laser-powered miniature Van de Graaf accelerator, which travels at close to the speed of light.

"Some of the laser energy is converted to electrostatic energy of the plasma bubble, which has a diameter of several microns. Conventional accelerators store their microwave energy in copper or superconducting cavities, which have limited power-carrying capability.

"An interesting conundrum that has not been considered before is the question of where laser energy goes after being deposited in plasma. We know where some of this energy goes because of the presence of high-energy electrons emitted in a narrow, forward directed beam.

"One of these beams is emitted by a sling-shot action into a broad forward-directed cone, with several MeV (mega electron volt) energies and nanocoulomb-level charge. Paradoxically, another beam is emitted in the backward direction, which has similar charge but an energy of around 200 keV (kilo electron volt). These beams carry off a significant amount of energy from the plasma bubble.

"It is interesting to observe that answering a very basic question - where does the laser energy go? - yields surprising and paradoxical answers. Introducing a new technology, such as the laser-wakefield accelerator, can change the way we think about accelerators. The result is a very novel source of several charge particle beams emitted simultaneously.

"My research group has shown that the wakefield accelerator produces three beams, two of which are low energy and high charge, and the third, high energy and low charge."

Dr Enrico Brunetti, a Research Fellow in Strathclyde's Department of Physics and a member of the research group, said: "These beams can provide a useful high flux of electrons or bremsstrahlung photons over a large area, which can be used for imaging applications, or for investigating radiation damage in materials. If not properly dumped, they can, however, have undesirable side-effects, such as causing damage to equipment placed close to the accelerator.

"This is a particular concern for longer accelerators, which often use plasma wave guides based on capillaries to guide the laser beam over long distances. These low energy, high charge beams also carry a large amount of energy away from the plasma, setting a limit to the efficiency of laser-wakefield accelerators.

"This is an issue which needs to be taken into account in the future design and construction of laser-wakefield accelerators."

Research Report

RAY GUNS
Scientists find out where laser energy goes when a beam is fired into plasma
Washington (UPI) Mar 23, 2017
Researchers in Scotland have figured out what happens to laser energy when a beam is fired into plasma. Plasma is the most abundant form of matter in the universe. When it is fully ionized, and the positive and negative charged particles separate, plasma can host powerful electronic and magnetic fields. Researchers can create plasma particle separation by hitting it with a laser ... read more

Related Links
University of Strathclyde
Learn about laser weapon technology at SpaceWar.com


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

RAY GUNS
Spacewalkers Connect Adapter for Commercial Crew Vehicles

The long legacy pf space-farming leading us to Mars

X-Hab working seventh season of academic-aided innovation

Deep space gateway to open opportunities for distant destinations

RAY GUNS
Evolution of Arianespace governance ensures greater coherence with Airbus Safran Launchers

SpaceX hails 'revolution' after recycled rocket launch, landing

SpaceX launches first recycled rocket

Musk diving into minds while reaching for Mars

RAY GUNS
New MAVEN findings reveal how Mars' atmosphere was lost to space

Potential Mars Airplane Resumes Flight

Final two ExoMars landing sites chosen

Mars dust storm west of Opportunity starting to abate

RAY GUNS
Yuanwang fleet to carry out 19 space tracking tasks in 2017

China Develops Spaceship Capable of Moon Landing

Long March-7 Y2 ready for launch of China's first cargo spacecraft

China Seeks Space Rockets Launched from Airplanes

RAY GUNS
Vietnam set to produce satellites by 2022

Globalsat Sky and Space Global sign MoU for testing and offering satellite service in Latin America

OneWeb Satellites breaks ground on high-volume satellite manufacturing facility

Start-Ups at the Final Frontier

RAY GUNS
NASA laser communications to provide Orion faster connections

Space blanket floats away during historic spacewalk

'Ground Control' Arrives at Leicester University

Nanomagnets for future data storage

RAY GUNS
Astronomers identify purest, most massive brown dwarf

Fledgling stars try to prevent their neighbors from birthing planets

Fossil or inorganic structure? Scientists dig into early life forms

Gigantic Jupiter-type planet reveals insights into how planets evolve

RAY GUNS
ANU leads public search for Planet X

Juno Spacecraft Set for Fifth Jupiter Flyby

Scientists make the case to restore Pluto's planet status

ESA's Jupiter mission moves off the drawing board




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement